Com-Pac Yacht Owners Association

I got started on my rudder upgrade project today.  I am going to modify the flat plate on my '84 CP16 to a NACA 0014 foil.  I admired the pictures of Doug's foil (Doug142) and he kindly supplied a template printout of the foil shape.   I am going to use a hardwood leading edge and pink styrofoam filler covered in fiberglass.

The first step was to make a maple leading edge to give the rudder some impact protection.  I'm posting a couple pic's of the nearly finished piece.  I followed Doug's advice and have added 1" to the leading edge so it will end up 13" wide x 22" tall. 

(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/NACA-0014FoilRudderProject012.jpg)

(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/NACA-0014FoilRudderProject009.jpg)

This will be an interesting project to follow.

Keep us posted.

Greene:
   This is perfect timing as I'm about to embark on a similar project. I'm also going to turn my 23's flat plat to a NACA 0014 foil only instead of foam, I plan on using a series of foil shaped blocks and a hardwood leading edge just as you are. The "framing" will be wrapped in an 1/8" mahogany plywood and fiberglassed, giving the look of a wood foil rudder. My son, who builds surf boards, will fiberglass it for me- he's a better glasser than I.
   I plan on chronicling the process but, as of right now, don't know how to post photos here. I guess this is a good time to learn!
Bob23..thanks

Bob,

Your project sounds a lot more involved than mine.  As a tinkerer I look forward to seeing your project come together.  Lucky for us we can just follow Doug's (Doug142) lead and profit from his advice and experience on these projects.  I'd like to see someone else try a NACA-0012 foil on a 16 so we could compare them.  Any takers?

Last night I tested some old fiberglass resin I had laying around on a couple brands of pink polystyrene.  The resin ate the foam like I eat chocolate.  Doug was kind enough to remind me to look for an epoxy resin instead of the polyester resin.  That epoxy isn't supposed to eat stryofoam.

Mike  

I was thinking of a slightly different foiling method. Using one of two methods.

#1
~Start with the factory aluminum blade. As this blade has the correct depth and width for the hull's design.
~The leading edge would have a nice hardwood leading and trailing[?] edge prescribed to foil's shape.
~Glue on a single layer of pink foam board insulation. Both sides.
~Sand the foam board to the foil's shape.
~Shape and check the foil with templates.
~Using a woven 1-1/2 once fiberglass cloth saturated with West System epoxy...
~I'd wrap the glass cloth round the leading edge and over lap at the trailing edge. Pulling It tight.
~Sand her out when cured. And paint it.

#2
~Aluminium blade.
~Shaped hardwood leading edge.
~Glass cloth wrapped around leading edge.
~Pulled tight all the way to the trailing edge of aluminum blade.
~The glass cloth would not be touching the blade between edges.
~Leaves a hollow blade between the two edges.
~A couple of 1/4" drilled holes to let water flow in and out, when down or pulled up.
~The rudder would be flat sided. Is that OK? Don't know. Foiled? yes.

Note that when the epoxy cured and was sanded and low spots filled
the rudder 'would be stiff as a wedding cock' as they say. You won't be able to punch through the hollow part.

Bare in mind that the IdaSailor rudder is 3 lb heavier on land and 3 lb lighter in water then factory rudder.

skip.

Skip,

Your description #1 is exactly what I planned on.  I don't see any need for hardwood at the trailing edge.  At that point of the foil there is very little Styrofoam thickness, just metal.

I figure if it doesn't work all I have to do is clean the stuff off the stock rudder and I'm back where I started.  Well, maybe $30 poorer and I will have entertained myself through a couple weeks of this stiffwater season.

Mike
   

I've thought about this project too, but I'd try to cut the foam with a hot wire over plywood templates. Cutting plywood in two dimensions is easier than shaping foam in three dimensions. One thing to consider though, I agree that epoxy fiberglass is the way to go, but keep in mind, UV will destroy the epoxy so plan accordingly. See if you can find some sort of UV inhibiter to use with your epoxy and/or keep it painted.

--Greg

Don't cut with a hot wire. Use a sanding block and smooth your way to that perfect shape.
Takes about 25 minutes per side I'd guess. Check with a cardboard template cut from the foil picture.

kchunk...Well Ok then Hot Wire it is. Nothing wrong with it. I make my model boats out of glued blocks of foam and sand to shape using templates. I have zero experience with hot wire, never thought about a battery charger. Hummmmm wait! Maybe going in the house and saying to the wife, "I'm energized" will work.

I don't really cotton to R/C aeroplanes that are A.R.F.'s. I like building with balsa, stick and tissue. Some how they come out lighter in weight then the foam guys. Of course I sand almost every stick to nothing before I super glue it together. Maybe that's where the weight goes? My nephew holds my 14 ounce-72" wing span-two channel Carl Goldburg's Gentle Lady. I still have it with a .051 power pod. Boy does she fly nice. I going to fix her up with new battery pacs and give this plane to Dylan. He flys it pretty well. Uncle skip is trying to guide him into being a Corporate Pilot, both fixed and non-fixed wing craft.
West System epoxy is fortified with UV resitant polyester blend.
Think yard furniture.
If the paint goes chalky then there was no polyester in the epoxy powder paint coat used to coat the furniture.
This is present on cheaper Wal-Mart brands.

http://www.finishingtalk.com/community/

skip.

Quote from: skip on February 03, 2010, 11:17:09 AM
Don't cut with a hot wire.

Well, cutting with a hot wire is only my opinion. And what do I know...other than that's how they taught us to make composite aircraft wings and control surfaces in A&P school. I suppose both methods will result the same product. Sanding to match will get you close, a hot wire will be dead nuts...just my opinion...

After a brief search on youtube I'm certainly convinced that a hot wire is the way to go. Apparently the R/C aircraft hobby has adopted this method and you can find anything from complex CNC cutters to the most simple homemade solutions using a battery charger as a power source. This particular example was rather impressive:

http://www.youtube.com/watch?v=R0ZCnR_g6ZU (http://www.youtube.com/watch?v=R0ZCnR_g6ZU&feature=related)

I was picturing using a positive template and running the wire along the outside of the template, but this guy shows a pretty good example of using a single negative template to quickly make a tapered wing. Pretty sweet!

--Greg

That was a really cool hot wire video.
What is the template made out of?
I think the trick is to keep both ends
of the wire level so the core is the
same thickness/shape both ends.
Is the held end insulated against
heating and applying voltage to the hands?
Looks easy. Too easy.

skip.

The way you'd do it for a consistent wing section (like a rudder) is to put your wire through a bow and use two templates. The bow will keep it taut and allow you you follow the outside of the positive templates. The templates can be cut from plywood. I saw one video on youtube where the guy started cutting his templates from formica. Said that his plywood templates were so used that they were starting to develop flaws over the years.

Here's a link for a NACA foil generator:

http://darwin.wcupa.edu/webapps/javafoil/

I still have my old rudder blade and keep thinking to myself that I need to try this...partly because I keep bending my IdaSailor rudder.

Gee thanks a bunch  kchunk!  Now I have to build a hot wire foam cutter to complete this project.  The Admiral said to just hand sand it like I originally planned on.  (i.e. "You don't need another tool.")  But the tinkerer in me just loves a new tool/toy project.  Lets see, I have a used furnace transformer 24volt/40VA for the power supply and plenty of hardware junk around the house, so all I would need to buy is a 5' chunk of Nichrome wire ($3.50)   Sorry Admiral, it is kchunk's fault.

Don't mention it  ;)

Sounds like you got everything you need. If your wife gives you grief over the $5.50 let me know...I'll spring for the $5.50.

Watching that guy cut that tapered foil by fixing one end of the wire was a great idea for a swept wing.

How are making your foil template? I was thinking of using the foil generator from the link in my last post, printing out a 0012 or 0014 foil and taking to kinkos and getting them to enlarge it to what ever size I needed and transferring the paper template to a pair of plywood templates.

My wife would never gives me grief, just love and admiration.  Well .........maybe she just tolerates me.

Doug142 printed out a set of 14" templates for me and I have transferred them to wood.  Hopefully I can find some time this weekend to make my new foam cutter and spend some time building the rudder.  

Just keeping busy until the lakes start cooperating.

Just to let you know that I'm lurking in the shadows and taking in all this information, trying to assimilate it into my grey matter before I begin my rudder project. I'll either photo chronicle it here or start a blog.
Bob23

Just an idea to save weight on the rudder.   Drill several (perhaps 50-75, maybe more?) 1/2" holes evenly spaced throughout the aluminum blade, sand smooth..then glue the foam on. The idea here to keep the structural integrity intact while removing some of the heavy material.  The foam and glass will add strength back. If I recall correctly, I read a post on another forum about doing this with success.  Your mileage may vary.

IDA chose the NACA 0012 blade shape for Compacs on their foiled rudders after testing various forms.  Doug tried the 0014 design as an experiment.  And judging from his boats' speed (sailed w/ him 2 years ago), as well as his reviews of the performance, no question the 0014 works quite well.  Probably splitting hairs between the 0014 and 0012 on our little cruising boats.

Salty, that's a good idea, but without calculating anything, I wouldn't be surprised if the increased buoyancy from the foam on the rudder actually made it float. At the very least it'll probably increase the buoyancy of the new rudder assembly, acting against whatever method you use to hold the rudder down when sailing.

--Greg

Salty, my Ida rudder has positive buoyancy and had to rig a tension line to keep her down. I believe you will need all the weight to keep her down,.....Phil

I plan on installing a downhaul line to solve the buoyancy problem. This worked well with my old SeaPearl 21. Haven't worked out the particulars yet but all these brainstorms start with pencil and paper and morning coffee.
Bob23

I figured every bit of reduction of weight adding to increased buoyancy would good thing, what with thee heavy 4 strokes and all, but can see your points about holding the rudder down.  Would be cool to fit something like what the IDA rudder assembly has to keep 'er down and let it come up when grounded, then pushes it back down. Something like a truck engine hood auto-raise rod/dampener .

Let me get a pick and I'll post it.  Bob you may need a second or third cup to think this one through :)

Don't need to hold the rudder down if she's bolted down with a sheer pin from a snow blower auger.
The keel hangs lower and I don't usually run aground going astern. Some 6" deeper then the keel. Really?

Saber Saw out a rectangle hole in the aluminum blank and pour in some lead protruding out on both sides. That will hold it down. File to shape, then glue on the foam, cope the foam around the lead and shape all that to the foil. Glass over the works and paint.

skip.

ps: on my 23, the rudder draws 6 inches more than the keel. I guess the 19 is different.
I may need espresso for this one...with Sambucca!
Bob23

Skip, with my great sailing ability I have sailed backwards.............Phil

Actually, if you can keep it down, a little more buoyancy in the rear would be a good thing.  Offset some of the weight of these heavier, four stroke, motors that are hanging there.

Drill out a pound of aluminum? I suppose in theory you're right, but the difference would be negligible.

Step 2 nearing completion.  I ended up using a Shur-Form and sanding pads to shape the stryofoam even though I did make a hot wire foam cutter.  The foam cutter really would be the way to go if you have one.  My cobbled together power supply included a used furnace transformer which worked really well for about twenty minutes while I practiced.  About the time I was ready to use it on my templates it gave up.  Oh well, back to hand shaping if I want to get Step 2 done this weekend.

The hand shaping really isn't difficult or time consuming, so it worked out pretty well.  As you can see in the pictures it shaped up nicely. The rectangular sanding pads they sell at the hardware store for drywall sanding really work great for final shaping.  I didn't want to end up with the rudder lifter/holder line going through the stryofoam so I tapered the top edge down slightly to end just below the 1/4" hole for the line.  I don't think this will be an issue, but I'm not sure.  Any opinions?
Since the nose piece (wood) was already finished I ground out the nose portion of my template to make it easier to slide it along the rudder.

Next up will be coating it with epoxy resin fiberglass.
(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/RudderStep2005.jpg)
(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/RudderStep2004.jpg)
(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/RudderStep2003.jpg)
(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/RudderStep2001.jpg)

Mike, that's really coming out nice! It's going to be such a drastic improvement, not to mention the satisfaction of doing it yourself. Way to go!

--Greg

Mike:
   Thanks so much for the great photos and live coverage of this news event! It's helping me re-think a few steps in my own rudder project which, for now, resides only in my grey matter.
Bob23

That tiny bit of foam and wood will not displace enough water to make a modified and foiled rudder float. Do the math, or better yet just think about it.

skip.

Great pictures, thanks for showing us your work. Very nicely done!

One question for the gallery, would it be easier to 'glass if the top edge was tapered to the core plate? Or would it really make a difference?

mel

Quote from: kahp ho on February 07, 2010, 12:46:07 PM
Great pictures, thanks for showing us your work. Very nicely done!

One question for the gallery, would it be easier to 'glass if the top edge was tapered to the core plate? Or would it really make a difference?

mel

Thanks,  I was wondering about that as well.  I am also undecided about how to finish the bottom edge.  Would it be better to taper it as well?
Mike

Bottom edge on the IdaSailor rudder is just rounded nicely and DOES follow a wide in front narrow in back taper. I don't think I'd fill in the tangent where the leading edge 'hits' the blade. Just carry on the foiled shape.

skip.

Mike,

great job..................cant wait to see the final product and read about your test sail with the new rudder.

   hey mike, that is one first rate job. im inspired. even though i have an ida rudder (got lucky got one when they were still reasonable) on my 16, i might just take the old blade and follow your pattern. maybe if you could pass that template along to me i would appreciate it. im always up for a new project. send me an e mail if you would    thanks buddy my best to brenda

Sounds like Mike could be starting a new business- "The Mike-a-Rudder".
Bob23

Thanks everyone, but lets remember that the original idea, plan and template are all courtesy of Doug142.  He is responsible for all this fun.  He just decided it was more important to move to a new house than to play with his newest rudder.  Nice guy, but his priorities seem a little out of line.

Mike

I put the question to one of our rabid racers.  There is a Precision 23 berthed next to me and looking at it s rudder he suggested taking a piece of schedule 40 3/4 pipe split to snap on the leading edge of the existing rudder then tapering back to the trailing edge with epoxy and micro balloons.  Any thoughts?

The "rabid racer" solution will give you a straight taper which won't be a foil and may create as much turbulence as the original metal slab. With a decent pattern and a lot of grinding, one could achieve a reasonably good foil using the PVC leading edge and epoxy/microballoon fairing, but it would entail a lot more work and added weight than the way Mike's going about it.

OK I see what you mean.  There would be little or no wing effect.  We were looking at the Precision rudder which is flatter than the rudders shown in the photos.   Matt

Skip,

you and I have a lot in common, Model "A's" , RC planes and sailing so far.

I don't like the "ARF" stuff either and relish a good RC kit from the old days like Carl Goldberg, Viking, Sterling etc..........

I have an old "Buzzard Bomb Shell" that I have had for some time, 1930 design.

The "Buzzard Bomb Shell" I have fly on an inverted O S Max 40 four cycle flipping a 10" x 6 prop with a 8 oz fuel tank so she'll remain aloft for an hour with prudent use of the throttle.  More then enough power. Picked up the kit at the R/C show in Toledo, Ohio around 1982 ? Installed the Futaba and use three channels.
Also have a "Kloud King" 72" wing span, 11 " chord, three channel 3 and 3/4 lb. Build 'em light!! Don't need all that balsa I just keep sanding the weight away. And I think their are 13 others in the basement.

skip.

Skip,

Ive been out of the RC world for some time and it wasn't until the last few years that I venture back in to the field. When I retire in June of this year I plan on spending more time with the Rc stuff when I'm not sailing or the world of Amateur astronomer, I built a 12.5 f/5 scope last year and have been enjoying that as well.

Step 3:  Finished putting the thickened epoxy on the rudder to fair the edges and any major imperfections.  I ended up buying the West System 2 part epoxy.  (105 Resin, 206 Slow Hardener, 410 Filler)  The final shape seems to be pretty decent, so I am pretty excited about how it will affect the performance of the sailboat.  I put the fiberglass cloth on and applied the "wetting out" layer of epoxy.  After a couple of hours I can trim the rough edges off with a razor blade while it is still in the green stage of curing.  After 3 or 4 coats of epoxy and a little fairing work I can figure out how I want to paint it.  I still have a lot of white Pettit Vivid Antifouling bottom paint left over, so maybe I should just use that.

(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/rudder3001.jpg)
Epoxy Filler used to fair the rudder
(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/rudder3003.jpg)
(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/rudder3005.jpg)(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/rudder3006.jpg)

Anti-fouling? Don't do it, Greene. A rudder that nice needs a tricked-out paint job. How about flames? Or American flag? Or barber pole stripes? Let your imagination run wild, man!
Bob23

Wow. That looks like a 'Clark Y' air foil of a model aeroplane wing. Think it will fly?
I think it'll be slippery in the water and if a tad balanced will add that power steering
feeling to the tiller.

Yes flames Dr. Gregory House MD bought a cane with flames on it, to quote him. "Bitch'n!" And the good Dr. hardly ever exceeds 2.5 mph.

What? I luvs glass'n its fun and makes your shoes 5 sizes bigger.

skip.

Bob23 - Flames on something that goes 5 MPH?  Well, maybe only 4 MPH with me at the controls.  The Admiral read your suggestion and said I could put a "nekid lady" on it.  Lets see, I'm not really a flames kinda guy, but I am a fan of the ladies.....

Skip -  I don't think it will fly, but I can always hope. 

I am fiberglassing the rudder now - fiberglassing SUCKS!

Mike         

I like the Admirals idea. We could expand this to the rudder of the month club. You, know- Miss June...Miss September...you get the idea.
My rudder is going to be sheathed in 1/8" mahogeny. I have enough drawings of this thing and you have provided the motivation to finally start this project.
I have glassing too...gonna have my son, the surfboard builder do it. Off topic: Check out his blog at www.strangeflora.blogspot.com ...you'll be sure to find something interesting there.
Bob23

Mike, I'm really impressed with the outstanding sculpting work on that rudder.  It is turning out nice.  Almost makes me wish mine hadn't come with a foil so I could give it a shot.

Quote from: Bob23 on February 16, 2010, 05:28:38 AM
I like the Admirals idea. We could expand this to the rudder of the month club. You, know- Miss June...Miss September...you get the idea.
My rudder is going to be sheathed in 1/8" mahogeny. I have enough drawings of this thing and you have provided the motivation to finally start this project.
I have glassing too...gonna have my son, the surfboard builder do it. Off topic: Check out his blog at www.strangeflora.blogspot.com ...you'll be sure to find something interesting there.
Bob23

Bob23,  I can really picture your mahogany rudder.  It would be beautiful and probably look more original than mine.  Hmmm, maybe I need to make a second rudder with a NACA-0012 foil just to see how it compares.  Make sure you post some pictures for us.

Mike

I plan on photo-ing every step of the way. As of now, I don't know how to post pictures here,,,maybe I'll learn. In any event, I could always email 'em to you.
You have been the inspiration for me to actually start this project instead of leaving it in my head and on paper!
Bob23
(ps: Maybe you should paint the rudder green? Get it- Greene?)

Ironically, green is my least favorite color.

Mike

oops...back to the nekid ladies!
Bob23

Fiberglassing is almost done.  Good riddance, I am not a fan of the stuff.

Bob23 - You can get an  idea of what your wood covered rudder would look like under fiberglass in these pics.  I am going to be jealous of the wooden look yours is going to have.

(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/Fiberglassing007.jpg)
Maple Leading Edge
(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/Fiberglassing008.jpg)
Side View
(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/Fiberglassing009.jpg)
Profile

Wow!

OK now that ya gotter done, band saw the bottom off the rudder to equal the drop in the keel.
And saw out a 6mm aluminium KEEL BOOT and glue that on the bottom of the keel with a little proactive lip on the fwd leading edge of the keel and go rock hunting. Looks great.

skip.

Mike:
   True, mine may look better, being wood. But yours is real...mine is still in my brain!
Looks great and we are all anxiously waiting seal trial reports. And just whose female form will adorn this beautiful blade?
Bob23

Quote from: Bob23 on February 19, 2010, 04:19:33 AM
Mike:
   True, mine may look better, being wood. But yours is real...mine is still in my brain!
Looks great and we are all anxiously waiting seal trial reports. And just whose female form will adorn this beautiful blade?
Bob23

Bob23, I can't rush such a decision, I need to research, research, research - this subject needs more research!
Mike

Great job!

To those thinking of making one for a 23 have a look at the Compac website photo section for the 23s.   One photo of a new 23 on a trailer shows a very different rudder profile.

I wonder if what works for a 16 may not be the best for a 23.   

Why did you use the NACA 0014 instead of the 0012?

From what I ve read on the subject air foil rudders are the way to go and I like the idea of using the existing rudder as a base.  Its much stronger than the usual built-up type.

Matt

Matt,
I chose the 0014 instead of the 0012 based on Doug142's recommendation.  He already made a drop dead gorgeous NACA-0014 foil for his 16. Check out his website for pic's.  Doug seemed to be very pleased with the performance, so I didn't see any reason not to follow suit. Once again, thanks to Doug for all the assistance.

I understand that Hutchins is making/selling a NACA-0012.  It would be really interesting if someone would make a 0012 for the CP16 so we could try both out and compare notes.  Maybe they would even bring it to the CLR and we could swap them back and forth.   I am tempted to start one, but I think a cheap homemade jib furler is next on my list.  No-wait a minute, next on the list is to finish the hot wire foam cutter project.   
Mike

Matt,

I have the new rudder on my 23, however, I've never sailed with the old one, so couldn't offer a comparison.  Any 23 folks close by or passing through want to take the helm and see if it would be worth it to make the change let me know.

I've never measured it, but think it would probably be the NACA-0012 profile.

Mike: Yes, I agree those important decisions must not be rushed. If you need a hand doing the research, let me know!
Matt: Good point. I'll do some more research on my own to determine which foil is best for the 23. Good thing I procratinated starting it!
Bob23

(ps: I just took a peek at the Compac site and, yes, the 23's rudder blade is quite different. What really stands out, though, is the amount of the blade that is forward of the pivot point. This is something that I want to incorporate in my rudder to try to provide more balance. ie, to remove some weather helm. I know that the foil shape will help in this area but moving more of the area forward should also help.)

     it never fails to amaze me how much i have learned from com-pac people.

Bob did you notice how big the trailing edge is too.  Both of those things have to make a big difference.  Does anybody have Doug142 web site I can t find it.   Thanks  Matt

Matt,

Go to martindalewoodworking.com and go into his com-pac section.  He has some interesting projects in there.

Mike

Hey, Mike:
   I am wondering about the overall width of your new blade. Can you measure and post here? I'm having a diffucult time finding a NACA 0014 template on line... I know I found one awhile back but can't now. I have found a 0012,  printed it out and enlarged it to suit my purposes. Thanks...and thanks for sharing your blade-building adventures with us here at the site...very helpful
Bob23
(ps: Do you know what the width of the original aluminum blade was?)

Good morning Bob,

I measured the rudder and here are the dimensions;

Original aluminum blade thickness was 1/4"
Original blade width was 12"

Foil thickness at the widest point is 2"
Foil width is 13" (original 12" of alum. plus 1" of maple for the leading edge)
Note: The foil template that Doug142 printed out for me was set at 14".  This allows us to cut off the final 1" on the thin trailing edge for strength. 

I did my final sanding this morning - could use a little more but it is just a rudder.  I'm trying to convince the Admiral to break out the ol' Singer and make up a nice storage bag for it.   
Mike

Obrigado, Mike:
   We are all waiting to see the finished product. A 14" wide blade will probably be what I end up with.
   Funny you bring up a storage bag. My plan was to sew up a cover to be used while moored. My rudder is pulled up out of the water most of the time and I know the effects of UV on clear wood. Is having a rudder cover being too vain? I hope not.
   Any decisions on paint or whose photo will be on the blade? How about shark teeth!
Bob23

Bob,
I am surprised that your boat has a rudder with the same width as a 16.  It must be quite a bit longer. 

A rudder cover vain?  Yes, but at our age it is good to be vain about something.

I put some primer on the rudder this morning and was disappointed in the surface appearance of the fiberglass.  Too many imperfections for me to be happy with it.  Guess I'll have to put another layer of thickened epoxy on it before painting. 

I am still undecided about the paint theme for the rudder.  I tried to do some "research" today by watching the Sports Illustrated Swimsuit Show, but the Admiral said, "I don't think so Buddy!"

Mike

To find the measurements etc google
Rudder Blades & Centerboards
By Gougeon Brothers, Inc.
1. How to Build Rudder Blades & Centerboards
By J.R. Watson

Jamestown Distributers has it as well

Mike:
   My blade is very long. (That didn't sound right.) In fact, it sits about 6" lower than the keel. Makes a great "You are about to run aground, Bob" warning device! When I first aquired the boat, I thought that it might've been replaced by someone so I emailed Gerry or Rich a photo but they ID'd it as a factory rudder.
   I have a suggestion for your rudder graphics but I don't have your email address and I don't yet know how to post photos here. It is from an old Glen-L catalog (1953) and used to be on thier website but has been removed. It is tasteful, I can assure you but probably quite edgy back in '53!
   Doug has graciously and prompty replied to my emailed request for the NACA 0014 template so I may actually start this project soon.
Bob23...28 days till spring...snow is melting here in NJ!

Bob,
I sent you my e-mail address.

Are you still deciding between the 0012 and the 0014?  I would think with the longer waterline you would be looking at the 0012.  Or is the speed difference between the 16 and a 23 small enough that either foil would be equally effective

I am considering just painting my rudder camoflouge after seeing it primed.  Fiberglassing still sucks.

Mike

Mike,

Very nice work!

"I'm trying to convince the Admiral to break out the ol' Singer and make up a nice storage bag for it.   "

Might not be a bad idea. There was a company that built foam cored rudders awhile ago that ended up having problems if the rudders got to hot in the sun. Apparently the foam shrank and the change in pressure deformed the outer skin. I tried finding the info on it again but couldn't. Don't know what type of foam they used in those.

Shawn

Hi all,
This thread is looking good.  Just had to get my 2 cents in.,,,,errrrr okay a picture of my NACA 0014 foil rudder.
Thanks for all the nice comments. 

(http://i895.photobucket.com/albums/ac156/DOUGN6885/126_2674.jpg)

See ya at the Carlyle Lake Rendezvous.  That's my cajun canoe that I made in the background.  Sold .
Thought I would try my luck at posting a pic within this post.
Doug
More SNOW coming tonight !!!!

Mike:
   Me not being an engineer, I don't know which foil shape would be correct. But anything will be an improvement over what I have. I thought to try to mimic the keel...hmmm...wonder which one that is? Oh, dear... decisions, decisions.
   Again, mucho thanks for all the help from you, Doug and everyone else here at the site. I actually started yesterday- removed the zinc from the blade, drilled out a new pivot hole in the rudder and rudder head. Yeah, I sail in salt water and had to replace the rudder gudgeon this year. I'm switching from SS bolts to bronze for the rudder pivot bolt and the two bolts that secure the rudder head to the gudgeon. Should help. The bottom ear of the gudgeon was well on it's way to being gone completely.
   Doug is sending me templates so I'll start a-cuttin' as soon as they arrive.
Bob23 out (of my mind, some would say!)

I seem to recall a comment a while back that mentioned IDA tested both profiles and found the 0012 style foil to be more efficient.  That is what they implement on their rudders (for the Compacs anyway).   

With that said, the 0014 obviously works well too.  Probably splitting hairs between the two.

To all:
   Doug142 has graciously mailed me the NACA 0014 foil templates for 12, 13, and 14 inch widths. Thank you so much Doug! Dang...no I have no excuse for getting started! Looks like another major nor'easter here in NJ tonight and tomorrow. With snow. One could really get used to wonderful weather like this. My snow shovel has sparks flying from it, I've used it so much.
   With the weather going to Hades, maybe Saturday I'll get started on the rudder project. And maybe, just maybe, I'll buckle down and learn how to post photos here.
Bob23
(ps: Again- much Grog is due Doug!)

Well today I figured I could just make up a quick template for some kind of insignia, paint the template, and post the final product.  ARGGGGGGG! Seems the blue paint I chose to use with the template reacted with the white paint already on the rudder and I ended up with a bubbly mess.  Ok, I'm an easy going kind of guy so I kept the language pretty PG and moved on.  I cleaned off the mess and repainted the white.  No cool insignia, but here is what it looks like before I do the final touch-up and cleaning of the bare aluminum.

(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/RudderPainted004.jpg)
Side View

(http://i613.photobucket.com/albums/tt211/greene2108/CP16%20NACA-0014%20Foil%20Rudder/RudderPainted009.jpg)
Top and Side

Mike

Looks great! And you'll be so happy with the noticeable performance. Great job!

Looks really nice, M Greene.
Good job!
Can't wait to see you zipping along with it.
Doug142

Nice work,

This was a fun project to follow, thanks for the post.

Now I'm waiting for the actual test results when you take her out with the new rudder!

Will you really be able to notice the difference ?

Mike-  very nice handiwork!  I think you'll find the foiled rudder to be the biggest improvement yet for your boat in terms of handling.   

I used the IDA assembly on my 16 (and have one on the 19 ready to be installed) and was amazed at the difference it makes.  No more strong weather helm, much better controlled tacking, points higher into the wind and the boat tracks with less slip.  I also noticed a MUCH increased ability to hold a tack before weather helming in strong winds.  Yes, enough to hold the boat on it's lines to take water over the rubrail in a good breeze.  That was with new sails too.  She will fly compared to last year.

Adding a 155% genoa, roller furling and a decent main sail will really make the most of the boat.

Glenn..if you're waiting for a review before you make one, don't bother! This is a proven modification that has been tested by many sailors.   Just do it!

Salty,

I am anxious to get out on the water and try it.  I have an older 155 genoa which will be attached to the PVC roller furler I am in the process of building.  The main is OLD, but it'll have to do.  I don't want to spend $400 on a new one since I hope to go to a 19 later this season or next.  I'll start a thread this weekend about the furler to get some input from others.

No details, but here is the start of my prototype.

(http://i613.photobucket.com/albums/tt211/greene2108/Com-Pac%2016%20Roller%20Furler/RollerFurler001.jpg)

We test sailed the new foiled rudder today.  Even though the winds weren't as strong as we would have liked, we got to try out the foil.  The most immediate and obvious difference was our ability to easily tack with very little headway.  With the flat blade we would often stall in the middle of a slow speed tack.  The foil just doesn't put the "brakes on" when you throw it over.  Brenda actually found herself oversteering during these tacks.  It seemed to allow the boat to gather speed more easily as well.  The nicest thing about the new rudder was the ability to sail closer to the wind.  Last year we felt that the CP16 would struggle to go even close to  45 degrees.  Some days it seemed like we were closer to 80 degrees!  Today with gentle winds of 7-9 mph we consistently tacked back and forth at 45 degree each way.  When the wind would pipe up a little we could sail even closer than that.  I hand sailed the last three hours non-stop today by myself and had little or no fatigue from holding the tiller.  It does feel like it has "power steering" as someone said it would.  

I also wanted to note that the rudder does end up with positive bouyancy.  If the tightener is left loose the rudder will float into the raised position.

I can't imagine a less expensive improvement that we can make to these fine crafts that would have this much impact on their ability to sail.  I'll be doing the same thing to the rudder on our CP19 ASAP.

Mike and Brenda

   Thanks for the feedback, Mike. I'm looking forward to trying mine out but it'll be about 2 weeks till it's done completely. I don't know if I'd undertake one of these wood-rudder projects again...very labor intensive and that's not good for one with limited time.
   I've wondered if a small skeg installed just forward of the rudder would help even more. Maybe next winters project, eh?
Bob23

Come on Bob23 - Pick up the pace.  I've got the wood leading edge on and the styrofoam glued to the plate.  I'll be shaping the styro tomorrow, so you'd better get moving or I am going to lap you. 

Post some pictures already!

Mike

Harsh bells, brother. Harsh bells you ring indeed!
   Yeah, I've been slacking. Work has been busy and I've had the rudder home for about a week. I have decided to fiberglass the bottom 1/3  for contact protection (not that it ever happens, mind you) and finding a place to do that is a challenge.
   Currently, there are 3 coats of West System on the body and another clear coat using 207 hardener will be applied. After that, about 3 coats of Flagship varnish will be applied and then, and only then, will it be installed.
   Looks like rain this Sunday but Saturday I hope to sail aboard my friend Dennis' Morgan 30.
No, I don't drink Captain Morgans rum; the name is just coincidental. I like Gosslings.
   I'll give the photo thing a good honest try this weekend. Promise.
Bob23
(ps) your adventures into roller- furling have inspired me to make a retractable awning for my home using an old sail. The original plan was to not buy anything for the project but instead scrounge around my vast store of "good junk". Looks like I will need to buy a few things but it should be kept to a minimum. Needless to say, Linda (commander in chief) is not thrilled with the idea  of an old sail hanging off the front of the abode.)

Bob said it best in an email to me about the rudder project (paraphrasing slightly) describing that the planning and procrastination stage is very important to the outcome of the project.

So with over two years of planning and procrastinating, Bob's rudder is sure to be the most finely crafted, perfectly designed piece of aluminum, wood, and fiberglass mankind has ever seen, and will ever know for eternity.

Not currently though:
   For some reason unbeknownst to myself, the rudder turned a bit milky when left out in the rain the other night. Geez...it's supposed to be in water, right? I think I can remove it with mild heat.
   I'll be glad when this is over...it's turned out to be a bigger project than I anticipated.
Bob23

Bob,
Doug here.  What coating is on the rudder right now?  Epoxy resin?   Not that polyester resin I hope.

I have seen that happen to stuff before and wish I could remember why.  But it seemed okay once dried out. 

If you can email me and pics in the email.  There wasn't varnish on the wood was there ? before glassing it in.
dougmartindale at elknet dot net

Doug

Hi Doug:
   I checked some West System info I have. It seems that this is common and due to high amounts of moisture present. Yeah, rain usually has high amounts of moisture. I used 205 hardener because I was building in a cool environment. Only 207 hardener is designed for clear coating.
   The info states that mild heat will eliminate the moisture in the epoxy coating.
   Today I'll glass the bottom third or so and pick up some 207 hardener and hopefully wind up this project before I turn 85!
   Doug, I'll email you a photo of the "beast" so far but remember, this is a top secret project and there are some lurking here who don't believe I will ever post photos on this site. If the word gets out about this rudder, Obama may appoint a rudder czar and we all know what that would mean!
Bob23

Quote from: Salty19 on April 23, 2010, 09:31:58 AM
Bob said it best in an email to me about the rudder project (paraphrasing slightly) describing that the planning and procrastination stage is very important to the outcome of the project.

That Bob is full of helpful bits of wisdom.  Another direct quote that I can use with the Admiral. 

Bob23,
Ah! Yes, the old to much moisture thing. 

Yes, I will keep it secret.  I have been following this thread and understand the politics that is going on.  No leaks here.

doug142

Sure Bob23 -  you trust everyone else enough to send them super double secret photos and info on your rudder project, but not me.  I guess I know who you trust......  wait a minute. I did receive an email with pics of the rudder from you.  Sweet, who can I send them to?  Sailnet, Good Ol' Boat, everyone!  You can't stop me now Bob.

Bob23 for Rudder Czar!

Mike (Can't Keep A Secret) Greene

Start of my Foiled Rudder for the 19.  (Not Bob23's)

(http://i613.photobucket.com/albums/tt211/greene2108/1988%20Com-Pac%2019/r2.jpg)

(http://i613.photobucket.com/albums/tt211/greene2108/1988%20Com-Pac%2019/r5.jpg)

Mr M Greene,

I heard rumors that $$ may be paid to those that can keep secrets of high level rudder workings.
Are you in?

Hint.....Bobs rudder looks very good.  That is all your gonna get out of me, no matter how much you torture me with YOUR fancy rudder pics.

Doug

  Ok, I see where all this is going. You guys have got wind that I'm independently wealthy and you intend to drain me dry. Well it's not gonna work. Ok, who do I send the check to?
  Well, I didn't glass anything today but instead went out for the first sail of the season aboard my friend and fellow co-conspiritor-in-the-construction-trade Dennis' 1970 Morgan 30. Once aboard, we cracked the previously requisitioned beer and ceremoniously poured some in the Barnegat Bay to officially signal the start of the season. 'Twas a sweet sail, gents!
Bob23

Bob,
Soooooooooooo glad you got your first sail in for the season.  We are still landlocked here in Southeastern Wis.  Raining on and off all weekend and not very warm outside.  Summer Escape is all ready to go.  Even charged up the old VHF handheld to take along when we CAN go sailing.

If we just move South a few hundred miles.  hummmmmmmmmmmm.

Congrats.
Doug142

Quote from: Bob23 on April 24, 2010, 08:07:55 PM

  Well, I didn't glass anything today but instead went out for the first sail of the season aboard my friend and fellow co-conspiritor-in-the-construction-trade Dennis' 1970 Morgan 30.

Would that be a traditional keel centerboard model Morgan 30.  A sweet boat.  The mentor of our sailing group when I was in my late twenties (he was over seventy at the time) the late Henig Forman had one.  Spent a lot of time on that boat.  Most memorable was doing the Gulfport to Pensacola race, part of the GORC series.  The race wasn't much but hanging out with Henig and my buddies the crew was a real treat.

Yes, keel centerboard. About 5 years ago my friend bought it from a marina for 1500 clams with a new Yanmar. It was the deal of the century. He loving restored it and keeps her in pristine condition. She's a fast boat, narrow in beam and we regularly pass most boats in her length range.
Bob23

If anyone is interested:

I have a 3" long piece of a NACA0012 foil made from HDPE that is the size to fit a CP19.   This is the bottom few inches of an IDA rudder which I cut off as it was too long (ordered that way, but thought it was too long when I received it).

The foil shape at the cut is 100% intact.

Would be happy to send this to anyone who wants the actual foil piece to model it from.  I would only ask that you return the piece when you're finished with it so I can loan it out again or later use it for my own reference.  Send me an email if you want to borrow it...email is in my profile (click on my name to the left to get the address).

Since this is designed for the 19, I make no promises that the size is appropriate for other boats.

I will give Greene first preference since he's looking to build one now. 

Thanks Salty19, but I am almost done fiberglassing my new 19 foil rudder.  I stayed with the NACA 0014 shape as it worked well on the first one.  It seems to be a lot easier to do the second one.  Who says I'm untrainable?  We all certainly appreciate the offer.  That profile should make it pretty easy for others to get started.  I sure wish this entire thread would have been here when I was starting on my first rudder.  Fortunately several members gave me all the info and advice I needed to complete the project successfully.

You think Bob23 is actually working on a rudder?

Mike

Quote from: Greene on April 27, 2010, 12:00:43 PM
You think Bob23 is actually working on a rudder?

Mike

I will believe it when the said forementioned untouched pictures are posted.  :)
Until then...figment of the imagination from the Garden State!

You seem to work on projects with a feverish pace!  I work slow but steadily on boat projects.  Admittedly I didn't and won't get everything done this spring I wanted to do, but have plenty of time once Island Time arrives in her slip next week. 

This week is the barrier coat and bottom paint (it better not rain!!!), do a little work on the outboard, fix a small leak on the cabin rails (optional this week, it can wait until next) and get all the lines in place for launching next weekend.   

I was going to make the roller furling this week (Doug142 made me a nice mahagony spool-you are the man, Doug!) but I don't think the genoa I have will fit (luff a bit too long).   So may need to have it modified or buy a new headsail.

Salty19 "You seem to work on projects with a feverish pace!"

Yep, just one of my many, many character flaws.  I am basically a really lazy guy that has a bulldog determination on projects.  A little weird, but it works for me.

The Admiral is a little happier with me because I am finally reducing the fleet instead of adding to it.  I had one old powerboat hauled away and sold another.  The fleet is down from 5 to 3.  As soon as I get the nerve up to sell Puppy Luff it will be down to a very neat 2.  NO boats outside the garages?  I haven't seen that in a long time.

Mike

Now that's a dichotomy if I've heard one...Lazy and determined all in one package. 
There are people that can help with such flaws, you know.  j/k

It will truly be fun to meet you and Brenda in July.

Hang in there Bob, this modification projects can be a bit tiring. Just do not let it get you down...

   Last night I fiberglassed the rudder, only the bottom 8 inches or so for a little extra protection from impacts. It came out ok, just a few Calvin hairs sticking up. You know, Calvin and Hobbes? Calvin's hair?
   Tonight I sand 'em down, put on a few patches over Calvin's hair, and let it be till tomorrow. Weather around here is looking good for a Force 5 launching but I should work on Koinonia on Saturday instead of playing.
   But, maybe I'm just dreaming all this. Maybe it's not real at all!
Bob23
(ps: You feverish-pace guys make me sick! Really makes us procrastinating genius' look bad.)
(pss: I'm really looking forward to meeting you guys. If I come out, I'm bringin' this damn rudder so you 23 ers' can try it out. )
(psssss: You don't really make me sick; instead you provide great inspiration. On the wall of my office is a sign which reads: "Procrastination is the thief of time." A while back I was talking to a wonderful neighbor, now deceased, who passed that tidbit of wisdom on to me. As he uttered it, I had one of those Ah-ha moments. Made a sign out of it. I've made progress on battling with my procrastination. I'd be further along, but I can't seem to get around to it!)

Guys,
Bob23 is in fact making a naca 0014 foiled rudder.  I know because I have seen TOP Secrect documents (pics) verifying said such item.

It works great on cp-16's, Soon to know about Compac 19's, and yes Bob's will be the first Compac 23 to sport the fantastic 0014.
Bob,
These guys are near dying to see the rudder.  How about it?  Ya gonna show them? Or make em wait till the 2010 rendezvous at carlyle Lake?

Looking pretty good!!!!

Still not in the water,
doug142

Hey Salty,
Think you could trace that foil out on a piece of poster board and then fold it up and send it to me?

Bob,

Consider it done.  Send me your address, you have my email.

And do keep in mind this is a CP19 oriented blade.  Not sure if the CP16 version needs to be any smaller but in a week or so I'll see my old boat so will let you know.

Doug:
  I'm gonna make 'em wait!!! Hahahahahahahaha!!!
Bob23

Quote from: Salty19 on April 27, 2010, 09:40:23 PM
Bob,

Consider it done.  Send me your address, you have my email.

And do keep in mind this is a CP19 oriented blade.  Not sure if the CP16 version needs to be any smaller but in a week or so I'll see my old boat so will let you know.

I used the same template (that Doug142 so kindly sent me) on both the 16 and 19 rudders.  I'm not sure if all 19's have the same size, but it is the same width (12") as the 16.  The 19's is thicker and longer though.   Note:  The template we used allowed for an additional 1" in width (total of 13") so we could add a bullnose to the rudder for protection.  The extra length on the leading edge should also give us a more balanced rudder.  i.e. "powersteering"

I think I will swipe bob's design once he has perfected it. :))

Newt,

I hope you are a very, very, very patient man. 

Mike

We will re-define patience! Once this thing is done, I plan on building another this summer. Works on paper, anyway. I'll put together a step-by-step photo journal of the construction of the  "Beast" for anyone foolish enough to build one.
Bob23 

First off I have to apologize to Bob23.  My wife often says I am slow on the uptake and apparently I did it again.  Bob23 was sending off "secret" photos of his long-laboring project to a few of us.  As friends we should have realized this was a cry for help in posting the pictures for him.  (We all know about Bob23's photo posting issues.)  Well I am going to help out our friend (and not force him to beg for help publicly) by posting a photo of the "beast" as Bob23 so lovingly refers to his new rudder.

Sorry for not catching on earlier Bob23,  I'll pay closer attention from here on in.














(http://i613.photobucket.com/albums/tt211/greene2108/Sailboat%20ideas%20from%20others%201/Bob23Rudder.jpg)



Hehehehehehehehehehehe!

LOL, Mike you ain't right as they say down here.........

Mike:
   I thought you promised not to post this secret photo of my rudder. I am so shocked. Well, now at least everyone can see the high level of craftmanship that I have maintained in this rudder modification. The astute observer will notice that there are 3, count 'em-3 pieces of blue tape holding the rudder to it's shaft instead of the usual 2. Much stronger. And the graphics- well, I must admit that I'm not an artist so I contracted with the worlds leading marine rudder graphic artist- Mr. Wenda HeckamIgonnabedone who works alone in small secluded shop in the frozen mountains of the Sahara.  I'm sure you'll recognize the name.
   Seriously, thank you for picking up on my cries for help. It is true that I have not posted any pictures here at the site and I feel much better now that one of my Compac brothers recognized my weakness and brought it to light. And to think of the money I've wasted on my therapist. He assured me it was ok and that I'd get over it, that I was completely normal. Yeah, he's probably a powerboater.
   But there you see it folks, with your very eyes you can see that my rudder project is almost done and is not, I repeat, not a farce as some have alluded it to be. It fact I plan on working on it today. I'm not sure I like the blue tape...might paint it brown to match the sail cover and dodger. And I need to do the dreaded rudder alignment process, which I sure that veteran rudder builder Mr. Mike Greene is  aware of. In this process, one takes the rudder under construction and at noon, points it to the sun, and attempts a noon shot witht the sextant thus aligning it with the celestial body in question. If this is done correctely, it makes it easier for the rudder to maintain a true norht heading while running with the wind in the northern hemisphere.
   Bob23...you guys are killing me!

MIKE, BOB23, AND ALL,

As the instigator of most of this NACA 0014 rudder stuff I must say that you guys have taken this to a level way beyond my expertise. 
HOWEVER, I thought i had mentioned that the thicker edge goes to the front and the trailing thinner edge is at the rear. 
Also, also you better have permision to use that Com-pac symbol on items that are going to be sold.  Not sure about the number 23.

Tis looking  good.
Doug 142

THICKER EDGE IN FRONT?!?! GREAT TIME TO TELL ME!! OH WELL, I usually sail backwards anyway.
Bob23...smelling of epoxy!

While not up to BOB23's standards, my CP19 rudder is primed and ready for paint.

(http://i613.photobucket.com/albums/tt211/greene2108/1988%20Com-Pac%2019/19rudder2.jpg)

(http://i613.photobucket.com/albums/tt211/greene2108/1988%20Com-Pac%2019/19rudder.jpg)

Mike

Hey Bob23,  you think anyone actually thought that was the real "Beast"?

Mike:
   The "Lean Mean Greene Machine" rudder looks great! When do you anticipate sea trials? I'm shooting for a 5/22 launch. In the meantime, I'll finish up some varnishing and the chart table I described under the 23 section.
   Dunno, Mike. I think some folks are just scratching thier heads, wondering just what kind of nuts hang around here. Hey, it could be a real rudder!
Bob23
   

Let that epoxy cure under water after a few hours rest. Bolt her up her up and go sailing.
Don't forget the bushings shoulder to shoulder in the rudder casting. Zero slop! Even a little hold'em friction. With the rudder kicked fwd a bit she'll be balanced. Like power steering on the tiller.

skip.

rwdsr-

I received your email.  You accidentally sent it off to Greene (thanks to Mike for forwarding).   I've traced the foil and will get it in the mail to you this week!

Skip, thanks. I had to replace the gugeon head due to corrosion so those bushings are new. While wantering around in Lowe's the other day, I came across bronze bushings that will fit perfectly to replace the ones in the rudder head. I may go the whole 9 yards and get bronze bolts...mayne not.
Bob23

Salty, OOPS! Don't know how I got that confused, anyway thanks for the help all.

BobD

No worries :)

Today I sent you two traces of the NACA 0012 foil on construction paper.  In case you make a mistake cutting one out with the exacto knife to trace on some plywood, you'll have a second chance at it.  Good luck with the project--along with new sails this is the best modification you can make for performance!

Thank you again, new sails are next.  I got my iron genny the other day, but with the high water around here don't think I'll get out to try it out this weekend or not.  May just work on the trailer for my bass boat.

My 'double-ohh-14' is nearing completion finally. Anxious to get out in the boat to try it.
I did similar to above except the leading edge.
I used a 1/4x1" strip of oak (because that's what I found at the lumber yard) and placed that at the leading edge of the stock blade. I figured that still gave me the hard leading edge, without having to shape as much as Greene did. So I basically layed a 1" piece of pink foam down, stock alum blade on it, with the 1" strip at the leading edge, and another 1" pink foam on top. Glued it all together with some West Systems 105/206. After curing shaped it as close as possible to the NACA0014 printout that I traced to cardboard. When I had the shape, I epoxed a layer of FG cloth over the works, followed by 3-4 coats of resin, sanded, painted and primed.
The airfoil shape isn't perfect compared to my printed foil, but I figured getting it close is better than the stock flat blade. Have to get it done before summer is over.
I'd post pictures, but can't seem to get into my web host right now.

Excellent TeamSlacker,  It is very good to hear of another com-pac sailor using the naca 0014 foil for their rudder.  The improvement is immediately felt on the tiller and you WILL be pleased.  Good work, spread the word.  If anyone else needs the pattern let me know via email and I will send.

Instigator of the NACA 0014 movement.

Doug 142
Com-pac 16
Summer Escape
See you at the Carlyle Lake Rendezvous July 9th thru the 11th, 2010

Doug, I have been reading Lecture's book and he mentions a 0010 as his favorite waterfoil. Why did you choose 0014? Did you just like the width? Are it's stall characteristics the best? Just looking at various options...

Newt,

I thought you built your NACA foil rudder already!  Really, when I got the idea to build my own, I was looking at IDAsailors foil rudders and the huge price on them.  I thought, since I do some woodworking on the side that I could build my own and save hundreds of dollars.  So I did.  IDA uses a NACA 0012 foil and I surely didn't want to copy theirs and infringe in any way............... so I bought a foil generator program and researched several.  0010 would work.  Actually, probably anything better than the FLAT blade rudder will work.

That my fellow Com-pac sailor is the short version of why NACA 0014 foiled rudder.  It works.
Doug

I just followed Doug142's lead and copied everything I could (twice).  I'm a cheater.  Thanks Doug.

Mike

I haven't built it yet Doug. I guess I am just a little slow (just ask my kids), but still looking into various foils. I am looking at everything from a 0010 to a 0030 trying to find the best stall characteristics. I wouldn't worry about copying the 0012- that foil is not patented by anyone.
One of my main problems is that I'm out sailing too much, and I don't want to get any part of my boat out of the slip! Yeah!

Well, Newt...Doug can send you the 0014 foil shape/template and I can send you a 0012 shape/template.  So we have you covered on these!

Newt,
Actually I can send you any foil you want.   just tell me the width you are shooting for.  The stock Com-pac 16 blade is 12 inches wide,  we all have been adding 1 inch to the leading edge made out of some hardwood.  Mine is hard maple.  I punch in the computer 14 inch wide rudder, because you cut off or eliminate the last trailing inch.  to thin, breaks off, creates drag, etc.   SO you end up with a 13 inch wide rudder.  You can and some have added length to the stock rudder also.

Then you get to choose which foil you want......10, 11, 12, 13, 14, and so on.
These are symetrical in design.  Same on both sides.

Let me know if I can generate one just for you.  I can get it in the mail usually within a day.
Smooth sailing.
Doug
CP-16
Summer Escape

Has anyone had a STALL out problem with their rudder?  Other than the stock flat blade??
Thanks Mike C for offering the 0012.  I am just glad others including yourself, Mike G, Bob23, and others are making their boats handle better by doing the foil upgrade.

Remember also, you can make a very inexpensive roller furler also.
Doug

purchased a Ida, best thing I ever bought, but if you stall out the NACA design it is hard to correct, with the old spade rudder you could horse the boat out of the stall, even propel the boat forward by pumping rudder back and forth , I guess nothing is perfect........still the improvement in sailing ability far out weigh any draw backs.............Phil

Doug:
   Thanks to you for the foil and to Mike Greene and others for the inspiration. Or do I mean perspiration? Both. I plan to take this to the next level by experimenting with a more plumb rudder and moving even more of the body forward while narrowing the width of the blade. I'll have to measure mine but I know it came out wider than I planned. My gut feelings are that because of the increased wetted area, a little weather helm still remains.
    I just got the recent issue of "Good Old Boat" magazine and Shazam! what do you think is inside? An article on rudder design by Robert Perry. I haven't read the entire article thorougly yet but he does discuss rudder area. One mention is that rudder area should be 1.4% of sail area. Hmmm....now we are gettin' scientific, eh?
    Sometimes, one can overanylize stuff and forget about why we are here: to enjoy sailing and being on the water. The reason I don't formally race is that I don't want to start to define sailing in terms of winning/loosing and minutes and seconds. Another reason is that I don't like to loose but I probably would loose alot.
   Does any of this make sense?

Bob23
 

Thank you, you guys are great!

Doug- No stalling issues on the NACA0012, on both the 16 and 19.  Very responsive, a light helm feel, and if there just a little forward movement, tacking has not been an issue.  No, wait, I recall having to jibe once on the 16 with the 0012 because of lack of steerage.  The winds had died to nothing so boat movement was limited.  Before the foiled rudder and new sails, forced jibing was an everyday occurance on the 16. 

Every compac owner should not just "consider" the modification, but simply do it!

I have been reading alot about design- and Lecture said the fatter the rudder  the less likely it is to stall in slow water, but the higher the drag. So I am considering designs from 0010 to 0030.  Your experience with 0012 and 14 in encouraging, I just want to see some data before I dive in.

   Iv'e had the same experience as Salty. My 23 definitely tacks better, points higher and I have yet to stall. The boat, that is. Part of the performance problems I have is due to my blown out mainsail but it's not in the budget yet to replace it. But, following the governments lead, I may throw the budget to the wind, so to speak, and just buy it.
   Newt: Data, schmata. Repeat after me: "I need a foiled rudder...I need a foiled rudder...I need a foiled rudder." That's it, see how easy it is? Seriously, you will wonder how you ever sailed without it. If I were closer, we could build a wood one. So far, no wear problems despite 2 times touching bottom. The next one may be longer and narrower. I might experiment with prototypes made with plywood, ground and sanded to the correct shape and painted, just to try out different shapes without committing so much time and money as my wood one consumed. But, hey, Koinonia is worth it.
Bob23

Finally got out on the water with the foil rudder this weekend. All I can say is, read all the other comments above and my experience is the same. If you're on the fence just do it, noticable improvement.

The big things I noticed in the couple hours on the water:

-tiller effort is less (power steering)
-it was a bit gusty yesterday, with the stock flat blade, when you were close hauled and you'd get hit with a gust and not let out the main, the boat would heel over to the rail, it would take almost both hands to hold the tiller and fight it from turning into the wind, which would cause the stock blade to start braking more than steering, you'd slow down and be forced to point into the wind basically. Now with the foil, the rail dips in, hold the tiller with one hand and keep it on course, watch the gps and you accelerate and can hold that course and speed. awesome
-seems to be pointing much better into the wind. I have some gps plots with the stock blade and will have to compare them to plots with the foil, but I think I deleted some of my track yesterday so might have to wait till next time. I seem to recall previous days on this lake, taking a half dozen tacks to get back to the upwind side of the lake, where yesterday it was only 2 or 3.

No regrets from this guy spending the time or money building it.

Wow!
What a recommendation for having a foil rudder.  Love it!!!!
Great.  What more can we all say?  Just do it.  If you need help, ask.

Doug142

ok guys,
you convinced me i NEED the foiled rudder, it looks a prety easy diy project
the most challenging for me would be to make the wooden leading edge, other than that i did some fiberglass projects before and i dont mind it.
now for the template, would anybody still willing to share the template with me?, im thinking to do the 0012
thank you
Gabriel

I will be building my third foiled rudder.  I have done a CP16 and a 19, now I will do the Com-Pac 23/3 as well.  I can't think of a single better improvement to these boats than foiling their rudders.  I just wish I could make one as beautiful as Bob's. 

Mike

PLEASE:
  If this continues, I won't be able to get my head of the cabin! Seriously, and I've said this before: I could not have even started my rudder project without the help of so many fellow boat nuts here at the site. All I did was take Doug142's template, apply my appitude for over complication, spend some hard earned bucks and hours and, Voila! A blade. I'd love to interchange it with a factory foiled rudder as a comparison test.
  Mike: Best of luck with your new "Wrinkles". Keep us posted!
bob23

You guys have inspired me to do this, but I have a couple of questions.  I am planning to do the foam core wrapped in fiberglass method for ease, time, and cost factors.  However:
1. What type of adhesives did you use to attach the foam to the stock aluminum rudder blade?

2.  Any issues with the fiberglass resin cracking where it meets the aluminum rudder blade?  I ask this for two reasons, I'm concerned about keeping this mod from failing due to water infiltration, but I am also contemplating a change in design(see question #3)

3.  Instead of building a wooden leading edge, why not shrink the foil shape to the size of the factory rudder blade, hot wire cut my foam to the width of the rudder blade, thereby using the aluminum rudder blade as my protection in the event of a rudder strike?  I'm assuming that no matter how it's constructed, that with any rudder strike I would be looking at some possible damage and repair to the coating.  It seems to me from everything I've been reading is that it's the foil shape that makes the difference, I would in essence end up with a foiled rudder in the same dimension(length and width) as the factory Compac rudder.  Thoughts or concerns?

Thanks in advance, I love this site, so much great info!

Quote from: Smier on April 25, 2012, 11:15:36 AM
3.  Instead of building a wooden leading edge, why not shrink the foil shape to the size of the factory rudder blade, hot wire cut my foam to the width of the rudder blade, thereby using the aluminum rudder blade as my protection in the event of a rudder strike?  I'm assuming that no matter how it's constructed, that with any rudder strike I would be looking at some possible damage and repair to the coating.  It seems to me from everything I've been reading is that it's the foil shape that makes the difference, I would in essence end up with a foiled rudder in the same dimension(length and width) as the factory Compac rudder.  Thoughts or concerns?

Part of the "balanced' feeling of the foiled rudders is because surface area is added forward of the leading edge of the stock blade. Creating a foil that is the same width (12") as the stock blade will help overall, it won't have as light of a feel as a foil that extends forward.

I did my rudder with foam/fiberglass without any kind of other protection for the leading edge. I went aground on a sand bar last week while motoring at about 4-5mph. The keel hit first, but the rudder took enough of a blow to rotate it up a bit. When I examined the rudder afterward I lost some bottom paint from the bottom of the rudder, but no dings or crushed areas. It would probably be different hitting rock or coral, but this was only the second time I've hit ground in 5 years, so I'm not too concerned about grounding damage.

Good to know!  Maybe I'll just cut the whole thing from foam and worry about repairs if/when I damage it, it's not like I plan on running aground...  If I'm going to do it all, I want to get the best possible results, I just know that I'll never take the time to carve out the wooden piece some have used for the leading edge of theirs.  Any thought on adhesives for the aluminum to foam bond?

Instead of a hardwood leading edge you could just add 2 or 3 layers of matting in that area.  It would give you some extra stiffness and impact protection.  That is what I am going to do with my third rudder upgrade. 

As far as adhesive choices you can use the epoxy or just buy a tube of styrofoam adhesive at a hardware store.

Mike

any one still have templates?

(http://i1125.photobucket.com/albums/l594/CPYOA/025.jpg) (http://s1125.photobucket.com/user/CPYOA/media/025.jpg.html)I found the templates on-line and printed them out.I can't remember the site but if I found them it couldn't have been too hard.I read and reread all the posts on this subject before
I started.I used Bob's suggestion and moved the leading edge forward.Everyone seemed concerned about the strength of the leading and trailing edges so I made the framework out of aluminum.With my background I'm more comfortable working in metal but that's just a personal preference,I used 3/16 rivets because I don't trust my welds on old aluminum.I found a site were they tested trailing-edge profiles and mine match their ideal perfectly,just dumb luck on my part.A good tip was to drill a hole in the  bottom of the blade then drive ln a nail to help hold and rotate during fabrication.Worked great but I drilled and tapped for 1/4x20 bolts instead.Later I used these to fasten a 1/2" aluminum skid-plate as per Skip's suggestion.With the low water levels in the Great Lakes it seemed like a good idea.I've yet to test it as I'm still putting the rest of the boat back together.Good luck....Doug

Ssullivan:
   I have the templates. If you pm me your address, I can make paper copies and send them to you. I have NACA 0014 with 12", 13" and 14" chords.
Doug:
   Pretty cool idea working in metal. Probably the same reason I made mine of wood- that's what I work best in. Mine is ready for a recoat of epoxy before she goes to work this season.
Bob23

Well, it's time for me to get started on my rudder mod.

I have an extra used CP19 rudder blade. The blade is bit pockmarked so I have to clean it up a bit first.

Where are you getting the templates? I am interested in making a 0012. I loaded up the java app on http://darwin.wcupa.edu/webapps/javafoil/ (http://darwin.wcupa.edu/webapps/javafoil/) and it does put out a design but I am not sure what to do with that. Do I just size it up to fit and I am good to go?

Doug, Mike, Bob,

I've just reread this thread (for better or worse) to try to figure out if there was any consensus on whether the NACA 0012 or the NACA 0014 was better and where to get the pattern.

I noticed that online there is a NACA 0012-34 and a NACA 0012-64.  Both have maximum thickness of 12% at 40% back from the leading edge.  The -34 has a sharper leading and trailing edge.

Which one have people been using for rudders?  I think the NACA 0014 is the same except scaled so the maximum thickness is 14%.

A good URL for patterns is http://www.airfoiltools.com/airfoil/details?airfoil=naca001264-il (http://www.airfoiltools.com/airfoil/details?airfoil=naca001264-il).  With this you can make your own patterns

This is a set of coordinates for plotting NACA 0012-34:

  0.000000  0.000000
  0.012500  0.011330
  0.025000  0.016800
  0.050000  0.024930
  0.075000  0.031330
  0.100000  0.036530
  0.150000  0.044930
  0.200000  0.050930
  0.300000  0.058000
  0.400000  0.060000
  0.500000  0.058270
  0.600000  0.053200
  0.700000  0.044800
  0.800000  0.033200
  0.900000  0.018670
  0.950000  0.010270
  1.000000  0.001200

This is NACA 0012-64:

  0.000000  0.000000
  0.012500  0.018130
  0.025000  0.024530
  0.050000  0.032670
  0.075000  0.038130
  0.100000  0.042400
  0.150000  0.048670
  0.200000  0.052930
  0.300000  0.058270
  0.400000  0.060000
  0.500000  0.058270
  0.600000  0.053200
  0.700000  0.044800
  0.800000  0.033200
  0.900000  0.018670
  0.950000  0.010270
  1.000000  0.001200

The above sets of numbers give the curve for a 1/2 section (where 1.00 is the back end).  Multiply the second column by 7/6 should yield a NACA 0014.  Multiply both columns be 14 if you want a blade width or 14" and then convert to fractions (round to 1/16 or 1/32).

Here is a rendering of NACA 0012-34 plugging in the numbers into xfig and doing a cyclic interpolated spline.

(http://www.faster-light.net/remote-access/naca-0012-23.png)

Has anyone put more rudder area forward of the original aluminum blade?  The IDA, for example, is a more balanced rudder in addition to being a foiled rudder.  A balanced rudder has enough area forward of the rudder pintel vertical pivot line to counteract the force applied to the tiller by the area that is aft of that vertical pivot line.  That is one of the reasons that the IDA doesn't not fight so hard to bring the rudder back to center.  Both my original flat blade and the IDA are 12" wide.  I take it that is the reason why 2" is added at the front (besides impact damage) in the 14" wide rudders.

Curtis

Curt:
   With respect to adding rudder area forward of the original blade, I have added about 2" when I made my wood foil. Of course I have nothing to compare it with, but the foiled rudder works great. Of course my reason for adding forward area was to combat that dreaded 23 weather helm. If I had the time, I'd make a bunch of different interchangable foam prototype blades that I could slide over a stock aluminum blade to test for comparison.
   Bob23

Bob,

Thanks for the reply.  IDA is 12" wide with the whole thing pushed forward 12".  Seems the DIY solution is to go with 14" and overlap the blade with 2" forward.  I have the IDA and it works well.  A just for comparison temporary rudder swap at a future BBB would be interesting.  If I build one I can do my own rudder swap (and see if I can notice any difference).  Since I already have a 12" 0012, maybe I'll build a 14" 0014.

Anyone know if IDA is using the NACA 0012-34 or the NACA 0012-64 template?  I have two pairs of rusty vernier calipers, so I could clean them up and take a look see.  Anyone know exactly which NACA 0012 or NACA 0014 (ie: the -34 or the -64 for NACA 0012) they used, or is these all the mysterious Doug142 template?  Apparently the Doug142 works quite well so for those that built them why worry about exactly which pattern it was.

Curtis

I am spooling myself up for having a bash at modifying our C16 rudder, and was wondering what weight (and how many layers) of glass you chaps are using on the foam foiled rudders?

Gordon
C-16/3 #2767 'Applejack'

Gordon,if you search the archives on this site you can find everything you need to know.Not having a clue how to get started,I simply followed the advice and instructions everyone here generously shared.If I could remember exactly what I used I'd simply post it(it was a while back).It was a fun project.You won't regret it........DougN

I used a single layer of glass on my first rudder and found it to be too easily dinged.  The next couple I used two layers which worked perfectly.  

Mike

Here's a few photos of my CP- 23 rudder project...

More....

More.... I'll post a few more photos as I make progress, Lance

  Very nice Lance and very similar to mine. Wish I could find the links to my build...and that I could remember how to post photos here. I sheathed mine in 4mm (I think) Okoume  plywood that I purchased from Chesapeake Light Craft. It was expensive- I still have over half a sheet left!
  What a difference in made in the boats handling and pointing. And, it's pretty to look at!
Bob23

Bob, I'm very familiar with your rudder project, I followed your posts closely among others before I started mine. I've completed the glassing since the last photo and will be ready for paint soon. I've got several deck repairs and mods underway and will do all of the painting at the same time. Unfortunately the boat is under the workshop shed so it may be spring before the painting happens, although in NC you never know what the weather will do!
Thanks for the comments, Lance