Bonding Wood Backing to Fiberglass Shell

[76SeaRay]

I am ready to start putting new wood into my hardtop. This is for support and to strengthen the fiberglass in some areas. It provides screw and bolt points holding windows and trim in place. The fiberglass shell is from 1/8 inch thick to about 1/4 inch max where the wood goes in as a backing. Which is better to bond the wood in place, thickened resin, peanut butter, or structural putty? The wood (marine plywood) is smooth but the fiberglass is a bit rough in spite of grinding out the old wood to be relatively flat. I am concerned that thickened resin may not fill in well enough.

Thanks...

 

[kcassells]

post some pics

 

[Scott Danforth]

thickened PB and use a notched trowel like laying tile

 

[76SeaRay]

Here are a couple of pics...

 

[kcassells]

If those wood pcs. are going to be the finished ends then give them a 45 deg clip. That way the glass will follow the contor and no need for pb there.
Prior to install soak all edges and flats with resin. Let it soak in and dry. Then install.

 

[76SeaRay]

No they won't be finished ends or showing. They sit on top of the gunwale and bolt down the intermediate hardtop (surround the lower windshield and support the upper windshield - note my profile pic). Hidden by the fiberglass outside and interior covering on the inside.. Picture is with the intermediate hardtop upside down on my work table.

 

[kcassells]

R U glassing them?

 

[76SeaRay]

Not planning to glass them, just coat them with epoxy and then epoxy to bond them in.. They won't have gelcoat on them. They are marine grade plywood.

 

[kcassells]

So be it.