Tow Boat US The Good And The Bad

[natecert]

Bushwacker. The plan is to replace with 3/4 Coosa 26 and gel coat it. As you stated I will shorten it about 2" and move the roller back the same distance. You beat me to it Re: thru bolting it down and will bed with 4200.

The old teak is 1/2 and surprising it has held up to 3' seas on the hook with a 4 to 1 scope.

[Bushwacker]

3/4" still sounds a little thin but maybe it'll work if you use epoxy and several layers of glass on top and bottom. At least it would crack before it failed completely! If it was mine, I'd use 2 pieces of coosa covered with glass, but I lean towards overkill on most stuff involving my boat, especially where I've had a failure! Your proposed 50% increase thickness will reduce max stress by a little over 3X. 2 pieces of Coosa will reduce max stress by 36X! The amount of deflection due to geometry at the end of that cantilever beam/pulpit will be reduced similarly. Deflections are also affected by the modulus/stiffness of the material, and I suspect Coosa is a lot stiffer than teak! Where you cut the slot for the bracket, don't leave square corners in the hole because that's a big stress riser. Nature likes a nice radius there as well as along the top and bottom edges of the slot to reduce stress concentrations caused by sharp corners/edges.

Couldn't find my old post I did on anchor bracket install and deck reinforcement, as it looks like search function only goes back 5 years, so here's a link to my photobucket album with some pics of that project. Anchor flukes are a little close to bow, so I have to slowly lower it to vertical before dropping it, but it works ok if you're careful. New anchor wenches have to be trained however! I used 2 layers of 1/4 or 3/16" plywood coated w/epoxy and wedged up under deck. The thin layers conformed better to the crown of the deck than one thick piece. I've since rotated the center cleat 90 degrees and changed the chain lock from a pin to the adjustable hook like you have. Good luck with the repair!

[DonV]

I'm with Denny, a single 3/4" is border line. On the weekend anchored up in the weekend "sandbar" seas it's fine, however in real water I'd give that some thought. I've broken the brass sleeve in a V-2 Lewmar windlass in 4' seas, so I know what crazy things can happen.

[natecert]

Looks as if the correct way is two 3/4 and will use 1708 topped with CSM, finally vale then gel coat. Had not thought of the radius corners but it makes sense. Regarding the thru bolting was planning to use six total, two near the bow and four aft of the center line. 1/4 should be ok with 4200 as bedding.

Ed