End Plate Effect for Keel?

[kearns]

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

[Pacman]

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.

[Bob23]

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

[MacGyver]

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

[kickingbug1]

   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.

[kickingbug1]

    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.

[Bob23]

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

[skip1930]

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.

[JBC]

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....

[kickingbug1]

  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 .

[deisher6]

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

[JBC]

Uh oh, Charlie, sounds like Santa's wish list is growing...

Happy Holidays to you and to all!

[Pacman]

  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