Y25 keel

[furdui]

Hi,to all Yamaha sailboat owners

I've created a problem for myself this year at antifouling time.The boat was still in the travellift,I had the curiosity to push the keel and to my great surprise it moved!!!!
There are no cracks inside or outside,the bilge completely dry,the nuts tight.
As shown in the sketch attached,the movement(about 30-40 mm each way at the bottom of the keel) is actually a hull flexing in area marked (A),outside of the keel grid.Taping the hull around keel inside/outside,it sounds solid everywhere.
A shipwright said that half of fin keeld boats and same age in the area have the same problem and it is fiberglass fatigue.To fix it,the floor has to be raised,4 hardwood formers glassed across the weak area,double the thicknrss of the existing bilge ribs.Big expensive exercise!
For the sake of a second opinion I went to another shipwright,this time on a slipway in a cradle(the boat sits on the keel),we had a second shipwright at hand,they inspected the boat in and out concluding it's noting wrong with my boat!
Has anybody had or noticed this problem? what did you do about it?
I would appreciate any replies.

 

[shemandr]

Yes, I've had that problem. My first keel boat, a Mark 25, had the same situation. And I found out about it the same way. I freaked out and had the yard cut open the floor and glass in re-enforcement. When they were done the keel wouldn't move at all when pushed. One of the yard guys who had been around forever told me that mine wasn't any worse than average. The hull oil canned before and after the repair. And the deck stepped mast was trying to convert itself to keel stepped - I called it the auto reef system. I sold the boat. I did the repair because I couldn't stand the thought of the keel ripping out of the bottom and continued to enjoy the boat for another 2 or 3 seasons. But that oil canning was disconcerting while working into a nasty chop in Little Peconic Bay, which is a normal afternoon condition there.

 

[Syntonos]

Yikes, Thanks for the heads up and great illustration. Plan to haul out next year and will give it a push and report back. Scary to think you aren't able to see any external signs. Keep us apprised of your plan of action. Always glad to hear from you, just wish it could have been on a more positive note!

Cheers

 

[furdui]

I've decided to fix the keel problem,and while the shipwright did his job inside(see pics 1...4,and he decided not to raise the cabin sole,keeping the original level),I cleaned the cast iron part of the keel.First a guy from marina with a strong water jet got rid of the paint,then with an air needle gun,32 needles 2 mm dia,I removed everything left to the bare metal(hard job in the heat of 36 deg Celsius),applied 3 coats of RUST BULLET INDUSTRIAL(pic 5),bog fill and fair the keel(pic 6),another 2 coats of rust bullet,then 2 coats of antifouling.
As for the keel dropping off,there was no way of happening,when pulling the boat out for inspection(for a second opinion) on a trolley with bad wheels,the whole weight was supported on the keel only and four times every turn of the wheel(assuming it was a square wheel) the boat was kind of pounding in top of the keel and the keel did not go through the hull!!!.
The cost of the whole exercise:AN ARM AND A LEG

 

[Syntonos]

Well Done!! , Looks like you had a good boatwright doing the work. Looks bullet proof! My Y25 has a 90 degree angle at the top but still very whimpy material wise. Thank you for the excellent photo documentation of the work. The Keel looks par for a steel keel, I intend to fair the keel and seal it with a paint like POR15 or equivalent to slow corrosion. Regarding sacrificing your limbs to keep your boat afloat.......... that's why we have two !
Cheers,
Syntonos

 

[furdui]

in the preparation for glassing,the existing cross ribs and surrounding hull area was ground off(including the 90 deg angle) and a 3/4 inch marine play wood beam on each side of the flimsy cross ribs were glassed in,pic1.
somebody told me,he,properly,treated his keel with rust bullet many years ago and it is still holding,people from rust bullet co claim that rust bullet beats por15(I do not like people promoting their stuff by talking down other's)

cheers
sail la vie