I am wondering if anyone has tried using an end plate to increase keel efficiency.
It is common practice to use end plates on aircraft to enhance airfoil performance and it seems to me that it might be useful on our little boats.
In addition, when the boat heels a few degrees, the keel effectiveness drops considerably. That is why C-16s sail best at minimum heel.
I am thinking that an end plate on the bottom of the keel that is a few inches larger than the keel footprint might keep the water flowing across the foil shape when the boat heels rather than simply spilling off as we slip to leward with the stock keel.
Any aeronautical engineers, naval architects, or shade-tree mechanics (like me) have ideas on this?
Hmmm...from one shade tree engineer to another:
I think this was discussed before but I could be wrong. First off, I'm not sure the 16's like the 23's sail better with minimal heel. I can't personally comment on the 16 but the 23 likes about 10-15 degrees of heel. I think as she heels that much, the waterline length is increased which results in maximum speed.
I'm not sure what you mean by end plate and certainly with something that takes off at 175 mph, the effects at 5-6 knots may not be the same. I've toyed with the idea of extending the keel back to just forward of the rudder to minimize turbulence but I haven't done anything past ponder this idea over a cool Dark and Stormy. Problem is, given enough rum almost anything makes sense! jk.
This would be a great question for Ted Brewer or Robert Perry. But I bet there lurketh around here an engineering mind or 2!
Bob23
There was a discussion recently in the 19 section.
http://cpyoa.geekworkshosting.com/forum/index.php?topic=5619.0
Mike
Mike, That discussion was focused on another aspect of keel design.
I am visualizing a flat aluminum plate, maybe 1/4" thick that would be attached to the flat horizontal bottom of the keel with the edges protruding several inches from the sides of the keel.
In theory, those protruding edges would help keep the water flowing past the keel surface instead of allowing it to spill off the bottom edge thereby maximizing the benefit of the NACA airfoil shape of the keel.
Shoal keels like the one on our C-16s begin to spill a good bit of the water flow when the boat heels more than 10 - 12 degrees.
That is why, when sailing to windward with the boat heeld over we make good speed over the water surface and it feels like we are really sailing well
but when we check our progress on the GPS we see that we lost much of our progress to side slip to leeward.
In my experience, I can make better progress to windward with 7-10 degrees of heel that I can with the boat heeled much past 12 degrees.
In theory, if the end plate does what I think it might, I could sail to windward better with more heel and less side slip.
yes ,interesting idea...but what do you do with the up and down motion of the hull,..it will act like a break
sounds like your describing a wind keel...
(http://www.beneteau235.com/images/wing_keel_800.jpg)
I think this might be more along the lines of what you mean, Hutchins addressed the issue on their top of the line product
The Com-Pac 35 and the redeeming benefits of shoal-draft Scheel Keel
Also;
From:
Henry A. Scheel
15 Modern Yacht Designs
International Marine Publishing Company Camden, ME
Designer's Comments on the Scheel Keel
From Life and Times Section (approximately 1972)
About this time, too, I designed and later was granted a patent on a sophisticated keel shape-now known widely as the Scheel Keel. This keel shape makes it possible for a sailboat with moderate draft to get along to windward just as well as if she drew more water.At the same time, the Scheel Keel does away with complicated centerboard gear and equipment. Another virtue of the Scheel Keel is that it provides a center of gravity slightly lower than the keel shape it replaces, so the boats are a bit stiffer. Likewise, in a seaway, when small boats really move all over the place, the Scheel Keel shape tends to suppress some of these wilder gyrations. (Had my name been Brown, Smith, or Jones, would there have been such a keel shape? Who knows?)
http://www.tartanowners.org/content.aspx?page_id=2155&club_id=284925&item_id=299986&new_view=1
MJ Cox
i have also thought this might work but have also thought that hutchins would have adopted this keel design if it would have made the boat sail better. and to answer a question the 16 does sail better the more she heels as does the 23 i suspect
Sailing best when up right...that be the Com-Pac 19. Different designer for the C-P 16 and maybe? the C-P 23?
Wing keels...more weight, less depth. The only reason for them.
One thing I be pretty sure about, adding more length to the back of the keel will make the boat harder to come about. Have to be able to turn this thing, not just go in a straight line. Even if the line falls off to the lee side. Sailboats are suppose to go side ways ain't they?
skip.
my 16 sails the best at around 15 degrees,
I have to agree with the original poster, Pacman, that (at least my) CP16 sailed to windward best when she was upright. I loved to put her rail into the water and really lean it over for the adrenaline, but when I wanted to get to a mark upwind in the shortest time, less heel was better to let the keel bite.
Poking around the internet you can find all kinds of opinions on keel end plates (http://forum.woodenboat.com/showthread.php?14823-Keel-End-Plates (http://forum.woodenboat.com/showthread.php?14823-Keel-End-Plates)). My uneducated opinion? Someone who really understands the aerodynamics involved and could design, fabricate, and attach a plate might mildly improve the boat. But there is a pretty good chance that you end up making the boat worse if you don't truly understand the variables, materials, and craftsmanship. Of course, if you use some cheap materials and attach it in such a way that it can be removed there wouldn't be any harm in experimenting.
If I were looking to make a CP16 go to windward better for the least amount of money, I would start with a foiled rudder, then new sails. If I really wanted to get crazy, I would think about adding a centerboard into the keel.
Quote from: crazycarl on December 09, 2012, 09:24:40 PM
sounds like your describing a wind keel...
(http://www.beneteau235.com/images/wing_keel_800.jpg)
Yup,
The wing keel is somewhat similar in that the wing does provide end plate effect.
However, on a wing keel, the end plate also has a foil shape to increase righting moment.
The design I am considering is flat and would be the full length of the stock keel so it would be shaped more like the anti-cavitation plate on most outboards.
I suggested some time ago, see "Removing the brakes", rounding the bottom of the C16 keel in the fashion of the top of a coning tower on a modern submarine. My idea was to reduce drag, and secondarily, provide more of an impact barrier. I think the design of the C16 stub keel was to let go of the water in a knock down to spill the air and round up. A wing keel might be tampering too much with a good basic design unless you like exciting sailing.
My new '87 C16, "Slow Dancing", is still on the trailer but the trailer is in a repair shop getting a new axle. I still don't know if she floats because I can't see all of the keel . . . I may add a couple of inches of sexy curve with a 'keel bra' after next season just to see if that approach will increase speed by removing the turbulence at the bottom of the keel. The curve will mimic half the cross section of the keel. Water in my neighborhood is noted for hidden rocks, not soft white sand.
Quote from: Citroen/Dave on December 11, 2012, 08:30:53 AM
I suggested some time ago, see "Removing the brakes", rounding the bottom of the C16 keel in the fashion of the top of a coning tower on a modern submarine. My idea was to reduce drag, and secondarily, provide more of an impact barrier. I think the design of the C16 stub keel was to let go of the water in a knock down to spill the air and round up. A wing keel might be tampering too much with a good basic design unless you like exciting sailing.
I believe you are correct regarding the current design which allows the C16 stub keel to "let go of the water" in a knock down. It follows that, as the boat heels, it will begin to "spill" water over its bottom surface, hence side-slip. The greater the degree of heel, the greater the side-slip.
My theory is that water that"spills" over the bottom surface does not flow along the length of the foil shape of the keel.
It that loss of flow along the surface of the keel can be reduced, the keel will become more efficient.
Another caution to keep in mind is that the ballast material inside the keel is concrete, not lead. Take this into account when deciding what anchoring device (bolts?) and sealant you decide to use. With the slightest moisture seaping into that concrete, you'll soon have a mud-like mess on your hands and maybe worse. I'm not an engineer, but my intuition tells me that there would be a LOT of stress on such a plate and that it would work very hard to free itself from the anchoring devices.
Kevin
Kevin,
That makes sense to me.
With that in mind, if I do make and install an end plate, I will use 3M 5200 adhesive to attach it to the bottom of the keel.
Then, if the project does not give the desired result, I can remove it using a special solvent for 5200 without damaging my keel.
Right now I am considering using 1/4" aluninum plate for the end-plate
Thanks,
Dave
A few notes, that may have already been made, but I will say anyway:
Adding a wing to the keel will add slower righting momentum. That is something I know for sure. It also makes the boat harder to pull out of the mud if it indeed does happen to be run aground.
There are quite a few boats that over the years I have pulled off of spots in our lake and frankly having that wing, we just make everyone disembark the boat, and then pull like hell till she comes loose back the way she went on.
This also adds more torque on the hull when pulling around due to the big foot below...
Sure the argument could be made that "our drafts are slight anyway in the big picture" and I would agree, but getting stuck is getting stuck, it happens.
Something to atleast keep in the back of your head.
Take pictures :D
Mac
I wonder if in the event of a grounding if the 5200 would hold and the glass would let go? Might be messy although all one has to do is not run aground, right?
Bob23
Pacman:
In one of his posts Skip, talks about a plate that he has fixed to the bottom of his '19 to provide protection from grounding. I have considered doing this too.
When single handing; I have intentionally grounded myself several times in the lee of small buttes leaving the motor idling in gear to stick there while sorting out gear and sails. My keel is not to much worse off, but it would be nice to have a plate down there.
It sounds as if you are going to do much the same thing as skip except extending out (horizontally) from the sides of the keel. I am interested to hear how it works out.
Good luck.
regards charlie
Charlie,
That is exactly what I am thinking:
A flat plate like Skip's but just a few inchess wider than the footprint of the keel.
If it doesn't work out I think I could remove it with a produt called Debond that is reported to remove 3M 5200.
Anyone tried Debond? How well does it work?
Iv'e had good success at using heat and patience removing 5200. I have a Makita heat gun and, well, patience...up to a point. I'm interested how this plate will improve the upwind performance so I'll be watching this post. It might reduce side slip.
Bob23
Pac - Debond (to be precise, the official name of the product is Marine Formula; Debond is the name of the company - but everybody calls the product Debond) is a miracle cure. I went through three aerosol cans in the course of stripping and painting my 19 and rebedding every single piece of hardware including the hull to deck bolts. You have to give it a little time to work - between 30 min and two hours. But it always loosens the 5200 enough for easy removal, and a little spray on a piece of Scotchbrite is handy for cleaning up any residue.
Amazingly, I found the cheapest source was ordering direct from the factory web site due to their modest shipping charges. Others sell it at a lower price, but kill you on the shipping.
Wes
It would be really interesting if you could gather actual data on performance before and after. Maybe you can calculate your tacking angles before and after, or even record a couple of sails on a gps/chart plotter before and after comparing the angles? The placebo effect can be very strong when making assessments based on the seat-of-your-pants.
Nate,
That is an excellent point.
It can be difficult to make objective assessments of the real impact of modifications, in part to the difficulty in standardizing test conditions.
To correct for variability in test conditions, I hope to be able to sail my boat side-by-side with a stock unmodified boat.
By sailing both boats at the same time under exactly the same conditions it should be apparent whether the mods are effective.
My old boat sails a lot better than it did when I bought it years ago but now it has a rotating mast that helps the old worn out sails hold a better foil shape so they work ok.
It also has a balanced rudder with 2" added to the leading edge that seems to help with lightening the tiller and reducing the tiller angle required to stay on course (and minimizing the resulting drag).
Next I am planning on fairing that balanced blade to a NACA 12 shape.
Each little change has made a small contribution and now my little boat work pretty well.
Still experimenting, still learning.
Steve Wood, a member of the West Coast Trailer Sailing Squadron (WCTSS) made end plates for his boat (a Bay Hen I believe) out of heavy rubber . He figures that when he heels the rubber "plate" bends down somewhat and increases the apparent depth and effectiveness of the plate.He says you need a fairly stiff "plate", maybe one or two thicknesses of truck mud flap material . He said he found the end plates helped a lot. Note: he also put an end plate on his rudder.
/// Frank ///
Frank,
That is very interesting.
Thanks,
Dave
Quote from: NateD on December 12, 2012, 02:59:58 PM
The placebo effect can be very strong when making assessments based on the seat-of-your-pants.
Very true. Especially when shells of money and time have been donated to the cause.
There are a couple of sailing forums that have some rather intelligent marine engineers aboard and they talk keel modifications in depth. Might want to check around a bit for some experts, ask good questions and provide good data before designing it.
A well-designed wing may very well help tremendously. But when you're off slightly in measurements, or don't take into account all the variables (it's rather complex math involved), a well intentioned modification like this may not bring the intended results.
Let me ask you, do you have an IDA Naca 0012 rudder, and have you correctly set your mast (forward slightly)? If not, get one or make a rudder and tune your mast as a first step to improving pointing and speed. After that, get new, quality sails. CP16's can and do sail well with these two modifications, of course along with skill and reasonable expectations. Other sail control goodies help as well (vang, purchased outhaul). You might not feel the need to deal with keel mods afterall.
Quote from: Salty19 on December 13, 2012, 10:01:18 PM
Let me ask you, do you have an IDA Naca 0012 rudder, and have you correctly set your mast (forward slightly)? If not, get one or make a rudder and tune your mast as a first step to improving pointing and speed.
I have not adjusted the angle of the mast forward to move the center of effort forward as others have done.
Instead, I made a new rotating mast base that locates the base forward so the mast can remain vertical but with the center of effort moved forward to releive the excessive weather helm of the stock set up.
Also, because the mast rotates, the surface of the mast now acts as part of the airfoil, thereby increasing the effective sail area a bit and further moving the center of effort forward.
The rotating mast modification has been a great success.
Also, I have three rudders: one stock blade, one that is a NACA 12 foil shape, and a third that is still flat but with 2" added to the leading edge to balance the helm.
To my surprise, the balanced rudder seems to be the best of the three.
My next effort will be to fair the balanced rudder to the NACA 12 foil shape in hope of further improvement.
The experiment continues.
ps I don't know how to post photos here but, if another more computer literate member would be willing, I could e-mail them for posting.
" I wonder if in the event of a grounding if the 5200 would hold and the glass would let go? Might be messy although all one has to do is not run aground, right?
Bob23 "
I was of the same mind. The 6mm aluminium KEEL PLATE glued under the flat of my keel is epoxied on using several bottles of Marine-Tex and rolled on to both mating surfaces and then wedged up for a three day cure on the trailer.
And the boot has been hanging on for years and has taken a beating traveling over rocks on the shores of Green Bay. Sure has saved the fiberglass from chipping down there. I wouldn't use 3-M 5200 Slow Set.
skip.
How did you add the 2" on the leading edge of the rudder? Glue,screws,==wood, fiberglass, what material? Mike
Could use a thickened epoxy like West System and 404.
That would be cheaper than marine tex......and could still be removed.
Since the plate would be aluminum..... heat applied to the plate would affect the epoxy and cause it to.break down.
Mac
Mac,
That is a great idea.
I might try an experiment first to see how much heat is required to remove an aluminum plate from fibergalss. (Don't want to harm the boat if I decide to remove the plate from the keel)
Thanks,
Dave
One other suggestion is use 40 grit to rough the aluminum plate.
And I would just maybe go around the plate edge where it meets the keel, not gluing the center up. This way it is less to try to remove if issue occurs....
Mac
Mac,
That is another very good idea.
It it ever did come loose, that would not be a serious problem and, if I did decide to remove it that will make it much easier to do with bonding on the perimiter only.
This is a great community! Lots of creative thought here.
Thanks, again.
Dave
Once a flat, glued 6 mm marine aluminium KEEL PLATE, saw cut to size and deburred is adhered to the pristine clean fiberglass of the keel with NO overhang there would never be any reason to want to remove said item. It's not like it's going to fall off. And the only purpose is to give a durable surface to glide over rocks that typically are harder then fiberglass and it's top coat of gel coat. It does nothing to enhance or detract from the sailing qualities of the hull or the rig.
As the design of a CP-19 [Bob Johnson] or CP-16 [Clark Mills] goes, they are still a 'barge' that sails best when stood up, with a relative slow calculated hull speed mostly due to a short waterline when compared to it's width and this combination gives the CP-19, more than the CP-16, all the comfort and stability, shallow draft and room down below. A great boat. I would not want to mess with Mr. Johnson or Mr. Mills's design. The shape, the length, the width, the draft, the quarter wave, the rudder square [foiled or not] foot, the sail square foot has all been taken into account and the appropriate messaging of these numbers has been refined as best as they can.
But for those who must muddle, muddle away. " a simple flat aluminum plate wont help. " True the plate is only for armor plate. Not water dynamics. I figure the ship's designer took all that swirly and eddy's stuff into account already. That's why they have the sheep skin and I don't.
skip.
http://www.sponbergyachtdesign.com/Keel%20and%20Rudder%20Design.pdf
around page 6 the end plate issue is covered,
in summary the end plate can reduce overall drag if is an efficient foil itself, otherwise it will increase it,
so although a good idea, a simple flat aluminum plate wont help,
This is a bit off-topic, but how about an end-plate for your jib too?
http://www.pressure-drop.us/forums/content.php?3167-Radical-18-Rotating-Mast-Debutes-In-Sydney (http://www.pressure-drop.us/forums/content.php?3167-Radical-18-Rotating-Mast-Debutes-In-Sydney)
Quote from: Pacman on December 14, 2012, 07:32:08 AM
I have not adjusted the angle of the mast forward to move the center of effort forward as others have done.
Instead, I made a new rotating mast base that locates the base forward so the mast can remain vertical but with the center of effort moved forward to releive the excessive weather helm of the stock set up.
Also, because the mast rotates, the surface of the mast now acts as part of the airfoil, thereby increasing the effective sail area a bit and further moving the center of effort forward.
The rotating mast modification has been a great success.
Also, I have three rudders: one stock blade, one that is a NACA 12 foil shape, and a third that is still flat but with 2" added to the leading edge to balance the helm.
To my surprise, the balanced rudder seems to be the best of the three.
My next effort will be to fair the balanced rudder to the NACA 12 foil shape in hope of further improvement.
The experiment continues.
ps I don't know how to post photos here but, if another more computer literate member would be willing, I could e-mail them for posting.
That's right, I forgot you had the swanky rotating mast! Very nice. Even with the rotating mast, do insure it's stepped slightly forward, not straight up. That makes a huge difference in balance. Some experimentation here could pay dividends. The naca shape should maintain or improve balance, and certainly will reduce a lot of drag. That one mod made our old 16 sail like an entirely different boat. And with new sails... That forward leading edge is huge in terms of balancing the helm, no doubt.
BTW, I wasn't trying to crush anyone's dream of modifying the keel, just pointing out what easier mods can be done to improve performance, and to talk to a marine engineer about specifics (shape, location, construction method) during the critical design stage.
Hey Pac Man:
What a thread.
I am curious it seems like this thread is talking about either about: raking the mast forward or moving the mast step forward?
I have mine raked slightly forward and it does reduce wether helm. As expected by moving the center of effort forward.
Have some sailors moved the step forward...If so to what effect?
regards charlie
Charlie,
I found that, with the stock mast base, I had to rake my mast forward quite a bit to get rid of the excessive weather helm. It did work but it looked wrong. The forward tilt of the rig was quite noticable when viewed from the side.
There isn't much sail area in the upper part of the rig so it takes several inches of forward rake to move the center of effort forward a significant amount.
My home made rotating mast base has relocated the base of the mast forward about 1.25 inches on the cabin top. With my mast vertical, the center of effort of the sail alone is at least 1.25 inches forward.
In addition, by allowing the mast to rotate, the side of the mast becomes part of the airfoil.
This effectively adds additional "sail" area to the rig and that added sail area is on the forward edge so the rotating mast moves the center of effort of the rig further forward than would be the case if I had simply relocated a non-rotating mast base forward by the same amount.
Hope this helps.
Dave
If have not mastered the art of posting photos but I could take some photos and send then to you by e-mail if that would help.
Thanks Dave.
I got dismasted the first time out..if I would have known when I fixed the mast step I would have moved it forward. However I have 5200'd in place so will just go with the forward rake. You are right it does look a little awkward.
regards charlie
Charlie,
Others have posted that Debond will remove 5200 so that might be an option if you are interested.
I used wood scrap I had in the shop so I only spent a total of about $10.00 on materials to make my mast step so it is not expensive.
If you might be interested, I could send you a piece of Ipe wood to make the base. You would have to buy four screws, a bolt, a nut, and three washers.
Also, if you don't have a drill press and taps and dies, I could drill the Ipe wood for the mounting screws and tap threads for the mounting peg (a sawed off and rounded stainless bolt). I used my stock mast base as a drilling jig so the holes would line up.
Might be a fun winter project.
If you wanted to go back to the stock set-up it would be easy to do that because you don't have to alter the boat in any way. It is a "bolt-on" set up.
Regards,
Dave
Hey Dave:
I have been thinking about moving my mast forward. If it moved less than two inches, seems that it could be done with the original step.
Did you move the support post inside, although from another thread that post might not be truly necessary!
If you email me pictures of your rotating, displaced, mast step, I will be glad to post them.
deisher6@midrivers.com
regards charlie
Q? If the mast is raked fwd, and presumably lifts the back of the boom up [keeping that 90 elbo],
does that drive the bow deeper into the water with a good blow?
skip.
This might be a slight digression from the very interesting technical discussion on this thread (which I am enjoying and from which I am learning a lot!), but I think we should caution especially newer sailors about attempting to remove all weather helm from out boats. True, excessive weather helm is a speed killer and an annoyance. Thus, all of us seek the so-called "neutral or balanced helm". But keep in mind that a certain amount of weather helm is built into most boats (at least most well-designed boats) because a certain amount of weather helm fulfills a safety function and also provides the skipper with a constant source of "feedback" on what the boat is doing and what the wind is doing to it. A balanced sailboat even with a "neutral helm" should want to round into the wind naturally when encountering a blow, giving the skipper yet another signal to stay vigilent. In the extreme case in which the skipper loses grip on the tiller the boat also should seek to stop herself by heading up. Above all, one should avoid making modifications so extreme that they end up producing a "lee helm" effect which is a safety nightmare, opening the door to unintended (and therefore very dangerous) jibes, etc....
Just a note of caution to add to this very interesting and fun discussion. Also, not intended to rain on anyone's winter parade of modification projects.
Best to all,
Kevin
Kevin,
I absolutely agree!
A neutral helm, or lee helm would be a serious safety hazard and would not provide the feedback we depend on to sail our best.
That said, the stock C 16 has a lot more weather helm than I like.
Too much weather helm can reguire the skipper to counter it by increasing rudder angle to maintain course. When this happens, the rudder begins to act as a brake.
By reducing, but not eliminating, weather helm the boat sails faster on a reach and upwind because less rudder angle is required to maintain course.
Skip:
No, I don't think it works like that. In raking or moving the mast forward, we are moving the center of effort more forward thus lessening that bloddy excessive weather helm that we all don't like. Unfortunately, I can't see moving the mast forward on the 23's. That would entail moving all the chainplates. I know this discussion pertains to the 16's but the prevailing advice for the 23's is to rake the mast forward a few degress. I've tried it and it works. Along with a foiled rudder, sails that still have a proper shape this will lessen the weather helm but not eliminate it.
I know this discussion started out about an end plate for the keel. My son has an old Irwin 21 FreeSpirit he recieved from my father in law when he got too old to sail. In the boats past, my father in law (Otto) added a skeg just forward of the rudder. It was nothing more than a 2x12 glassed on. (He was the master of Rube Goldberg modifications!) That boat sailed closer to the wind than any sailboat I've ever been on. And that with the worst sails you can imagine. It's a vertical daggerboard and rudder boat so she stays in balance. I've wondered if a similiar modification to the 23 would help but I'd like to discuss it with a real marine engineer before I undertake such an endeavour. I should get a picture of it for this thread.
Bob23
Bob23
That makes me wonder then if a Alerion would sail closer to the wind. If so, then by adding length to the keel and a rudder skeg to boot we would practically have small alerions without the depth........
We have one of this style boat on the lot........who knows when I will see the owners but when I do I will ask em how she sails.
Mac
i can see that the existing keel was probably cheaper to produce but i wonder given the purpose of the cp16 (as an entry level or rental boat easily trailered) the safety of the weather helm was a main concern. i doubt that a end plate just beyond the bottom of the keel would make the boat unsafe. i do think that the plate would have to be of a foiled shape (like those pictured) to be efficient enough. it would be a great project to try provided you could go back to the original shape if it didnt work out.
one might look at the rudder of a precision 165. the boat is lighter with higher mast and more sail area and more beam (14"). i think they sail to weather pretty well but i havent sailed one (most seem to be in florida). pictures of that keel might be helpful.
A friend has a Precision 15 keel sailboat. It appears to me that the same bolt on keel is used on the P165. Ballast in the specs is the same, me thinks. It's a typical wing keel so it fits in with our discussion here.
There is a good review on the P165 in the current Small Craft Advisor. Check it out. They liked it and said it seemed to be built well. Must be different than the 15...we had problems with it from day one...very cheap and weak hardware. Thin hull. A toy of a roller furler. Minimal standing rigging. Comparing that to a Compac 16 is like comparing a Ugo to a Mercedes.
But it would be cool to mess with experimental wing keels on the 16.
bob23
MacGyver
For the amount one must pay for a Alerion it should do a whole bunch more than any Com-Pac.
As Rich Hutchins said at the All Sail Boat Show Navy Pier, Chicago, " If your weather helming, your sailing out of control."
skip.
" although it would be a job, i think a thick aluminum plate [KEEL BOOT] the same size and shape at the bottom of the existing keel epoxied in place with drilled and tapped holes along its surface would enable one to bolt another aluminum end plate to it. '
Why drill and tap? Just tac weld a new experimental plate on and if it's not right just grind the tac and bust it off. Tac on a different and new shape.
" So improving boat performance is certainly worthwhile. " Wait a minute! The same amount of hull is still in the water, and it's the same shape no matter how many appendages are bolted or welded on the bottom, so it's still a barge, safe, stable, and comfortably slow.
"But if one is going to have to go all out to do that with, in my opinion, marginal improvements to show for it, then probably it's time to look for another boat! "
Now you talking and understanding.
I think this quest to reduce weather helm, while worthwhile, does distract some from the pleasures sailing the 16 (and perhaps other ComPac models). There are numerous ways to reduce weather helm when sailing. I've sailed both the original design and currently sail a '90 with the bowsprit, the arrangement of which does reduce weather helm some by moving the jib 11" forward and changing slightly the measurements of both sails, to favor more upfront. But believe me, this is not a tortise/hare story...both models are still pretty slow when heading to windward, and while weather helm is improved with a more forward position for the sail, it's not a night and day difference.
As virtually every post makes clear on this website, the greatest improvement for the 16 is a foil shaped rudder. That's one improvement I really can feel while sailing, even in light winds. I do not fight the tiller. Coupled with a bowsprit arrangement, the foil shaped rudder does neutralize the helm quite a bit. But really, for a ploddy boat that is not designed for speed, but stability (yeah, Skip, I like the name "Comfort and Joy"...sort of nails it for this kind of boat design, doesn't it?), the C16 is a genuine pleasure to sail pretty much as is, all models, most of the time. And now that I'm 70, it fits my needs perfectly!
Having owned and sailed numerous boats over my life, I settled on the 16 for entirely different reasons than those I had when younger. Speed's not a priority now, but I still find the 16 can do quite well in most conditions without being a dog. I once owned a Potter 15, which can beat pretty high into the wind. But downwind one day, in a stiff breeze, a 16 left my Potter wallowing in its wake. I vowed to get one someday, and I'm lucky to have been able to finally do that while I can still sail.
So improving boat performance is certainly worthwhile. But if one is going to have to go all out to do that with, in my opinion, marginal improvements to show for it, then probably it's time to look for another boat!
Clark Mills, the designer of the 16 and several other ComPac models, also designed a boat I once owned...a Windmill. A blast to sail, really, if you want to ride a rail all day. There was plenty of weather helm with that one, too, and if you let it round up as it wanted to do, you lost the race. Funny, the only problem with the rudder on that boat was that I lost it one day when my wife and I were howling across a lake. Simply blew off its gudgeons and into the drink. A paddle can make a pretty good rudder in a pinch, so long as you don't really need to go upwind anymore....
although it would be a job, i think a thick aluminum plate the same size and shape at the bottom of the existing keel epoxied in place with drilled and tapped holes along its surface would enable one to bolt another aluminum end plate to it. if it didnt work or a new shape was required you could simply unscrew one and install another. if the whole project failed to produce good results the plate could be left on .
Hey JBC:
I started out on a Windmill #150. What a boat for a youngster to learn on.
I agree that a C16 is a pretty good place to end up.. although a C19, 23, 27.....
Merry Christmas
regards charlie
Uh oh, Charlie, sounds like Santa's wish list is growing...
Happy Holidays to you and to all!
Quote from: kickingbug1 on December 24, 2012, 10:56:35 AM
although it would be a job, i think a thick aluminum plate the same size and shape at the bottom of the existing keel epoxied in place with drilled and tapped holes along its surface would enable one to bolt another aluminum end plate to it. if it didnt work or a new shape was required you could simply unscrew one and install another. if the whole project failed to produce good results the plate could be left on .
That is a very interesting idea.
It could allow me to experiment without risk.
Even if the end plate experiment is a total failure, I would still have a protective plate like the one Skip made for his C-19 and that is an improvement I would definitely want on my C-16.
Thanks,
Dave