Strut backing plate/ shaft log repair

[mapleleaf]

After a meeting with a rock last fall I've finally gotten around to putting my boat back together. All the bent up drive line stuff is out being repaired and pending its return I'm trying to have everything else ready. So I've bought all my fiberglassing supplies except the additive for the epoxy resin to thicken it for bedding ( I went with west system stuff, easy to buy off the shelf near home).
I'm clear on the grinding and clean up required to remove the shaft log and the old strut backing plate. What I'd love some advice on is how to rebed the strut backing plate in, when I removed the old one tonight it looked like originally it was bed in with silicone or the like and I'm thinking I'd like to use epoxy...thoughts?
I also plan coating the new backing plate with resin before install to get it sealed, if I plan on reglassing the plate in this weekend what kind of drying time am I looking at just for the resin on the backing plate( i.e.if I coat it fri night will it be ready to be glassed in sat aft???)

[sybrmike]

I'd use a thickened epoxy mixture to bed in the shaft log and strut backing plate. Personally, I like milled or chopped fibers - but cabosil, microballoons, etc. would be fine. Just like bedding stringers, you want the consistancy thick enough to hold shape, but thin enough to squish down without any voids. The goal is a thin layer (it adds no strength to speak of) that insures full contact. Like stringers, radius the top edges and build a fillet along the bottom edges to help the glass lay down.

By strut backing plate, I assume you're talking about the plywood section above the strut & & below the aluminum plate? A coat of resin would be good, but CPES may be better? With a properly mixed epoxy ratio & coated in a warm environment, you could glass it in after a few hours. Lightly sand the epoxy coating prior to glassing it in.

[Okie Boarder]

Most of the work I did with wood I would CPES one coat per side per evening, doing multiple pieces at once. A lot of my coating was done in cooler weather though. I bet you could put two coats of CPES on both sides in one day and bed it / glass it in the next day or later that same day.

I used cabosil and glass bubbles as thickeners. Cabosil when I wasn't going to need to shape or sand it (basic bedding) and glass bubbles for shaped / sanded areas (fillets).

[Ptownkid]

how do you make sure that this type of repair is going to provide a nice level surface to mount the strut to after all is said and done?

[Okie Boarder]

If placed in the same location and same orientation it should be the same. If not the strut can be shimmed when it is bolted up and would be the starting point for performing the alignment process.

[Ptownkid]

Fair enough...next question, would my backing plate in a 1992 saltare with composite stringers still be wood embedded in the glass?

[Tim405]

The materials wouldn't matter ( wood/ Alum) as long as the original strength of the repaired area is greater than or equal too the original structure - just clean clean clean... trichloroethane works really well and leaves no residue... when in doubt - add another layer of glass - 7780 glass weave @ 3 or 4 layers oriented 45 degrees from each other will give good strength - check out fibreglast.com - the have some great stuff. also west systems resin and fast hardener work real well... they sell microballoons also... if it'll work at 550 knots on a Learjet -then you oughta be okay. you want to spread the load across the hull as much as possible by blending the new layers into/over the existing glasswork.

[mapleleaf]

how do you make sure that this type of repair is going to provide a nice level surface to mount the strut to after all is said and done?

the strut is on the under side of the hull, so the backing plate is there , I believe, for strength and to tie off the steering cable, it's alignment not so crucial in comparison to the shaft log, which I won't do until I have the strut and shaft in place.....

Will West Marine have Cabosil or these Glass bubbles??? Newbie questions....

[Ptownkid]

I have a great supplier for alot of that stuff...great service and very knowledgeable.

www.rayplex.com they also do prop repair.

[WakeSurfCanada]

Hey Maple,

Check out Canada Composites! I have been dealing with them for all the products on my resto. Great guys and also very knowledgeable.

Located 410/Matheson in Mississauga

http://www.compositescanada.com/