SailNet Community banner
1 - 2 of 2 Posts

·
Registered
Joined
·
4,211 Posts
I say "nope" to the backing plate crowd. The cracks extend beyond the area a plate could cover, the surface is nowhere near flat, and you need reinforcement beyond the semi-flat area. A backing plate can't do this, certainly not with a bigger winch.

Sand or strip off the paint and add about 4-6 layers of 1708, in alternating dirrections, tapering, and extending about 2-3 inches beyond the winch base in all dirrections (farther than the stress cracks). No backing plate needed, but use extra thick (this is a thing--they are 2x the thickness) fender washers under the bolts.

This is how serious race boats do it, and it is the best way to deal with curved and complex under deck areas. Easy with the access you have. Won't take any longer than fabbing a good backing plate and MUCH more effective.

Obviously, if there is core that also needs to be dealt with, as well as the old holes.
 

·
Registered
Joined
·
4,211 Posts
What does alternating directions accomplish? 1708 is 45* biax, so an alternating direction would give the same fiber orientation.

In this case, I do think a backing plate/structural thickening will be all that is needed. The cracks are in the thin inboard end that looks relatively flat all the way to the edge. The cracks go right to the end of the layup, so there isn't a way to extend glass past them. The other side of the winch is cored and doesn't seem to be hinging, so a 1/4" fiberglass plate cut to shape so it fills that entire winch bed area, and bedded in thickened epoxy will work fine.

Mark
Think about what you said. Biax is one direction, and then 45 from that. But not 90 and not 135. Biax is not radially symmetrical like plain woven fabric. If this is not done, it will be weaker in one direction than the other. This 45 angle makes it easier to lay on curved surfaces, and the fibers lay flat, without crimp like roving, but you can't lay it all one way and get full strength in all directions. I made that mistake... once.
 
1 - 2 of 2 Posts
Top