End Plate Effect for Keel?

[Pacman]

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

[MacGyver]

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

Mac

[Bob23]

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

[deisher6]

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

[Pacman]

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?

[Bob23]

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

[wes]

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

[NateD]

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.

[Pacman]

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.

[Frank W]

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   ///

[Pacman]

Frank,

That is very interesting.

Thanks,

Dave

[Salty19]

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.

[Pacman]

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.

[skip1930]

" 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.

[ribbed_rotting_rusting]

 How did you add the 2" on the leading edge of the rudder? Glue,screws,==wood, fiberglass, what material?   Mike