transom

ok guys, what would you use to apply new plywood to the fiberglass tansom? also what do you think about using poplar wood in a boat,floor,transom?(plywood,boards)?:?:

 

Epoxy the new transom core (marine grade plywood) to the inner and outer skins of the old transom. They need to be clean and possibly roughed up a bit with a grinder to take a good bond.

Poplar was used as planking in small boats for years, but the good stuff (yellow poplar) has been all but cut down. The remaining cousins of this species are not nearly as good, having wider growth rings, less rot resistance and less strength. You can get poplar faced plywood panels, but this is usually cabinet grade stuff and not suitable for life on a boat.

Replacing the plywood core inside a transom has been discussed many times here. Try a search for transom replacement.

 

We always put 2 layers of 1 1/2 oz mat against the old fiberglass transom and then clamped a sandwich of 2- 3/4" plywoods with a layer of 1 1/2 oz mat
between them to the transom, all of that at one time and fairly resin rich.(polyester) If there is too much curve in the transom you can use more layers of thinner plywood. If you don't have enough BIG clamps (you don't) you can drill holes through the transom and plywood and use threaded rod or bolts and 2x4's to clamp it together and then plug the holes afterwards. Put plastic sheeting under the 2x's to keep them from sticking to things you don't want them stuck to. Also wax the outside of the transom first so oozes and runs will come off easily. I wouldn't use boards in the transom, plywood is more dimensionally stable and probably stronger. Sam

 

i often use drywall screws to pull
the plywood to the old fiberglass lots of resin rich mat to let it bind with out voids

 

Same here

I cut some 3" squares of ply to use as washers on the drywall screws that I used to pull the plywood into the curve of the transom. The tiny holes that you drill through the glass for the screws are easy to patch.

 

thanks guys,all good suggestions.i guess i'm lucky that the inside of the boat is open so i can get at it! i just finished ripping out the old transom and ground all the old plywood off. half was rotted the other half good.(DAMN IT!)well guess i'm on my way.maybe i'll get to use my boat this year!?--------------(1988 Larson 170 citation bowrider) 2.5 mercruiser....

 

you guys got any pictures? would love to see them!

 

mat

would that be chopped strand mat?

 

Chopped stran is what I used

Not to step on Sam's toes, but yes, chopped strand is what I used and what I've seen used. Don't worry about normal resin to glass ratios like you would for strength in a layup. Just get the mat saturated and clamp it well to avoid any voids. Your enemies here are gaps and voids.

 

Don't use poplar, it's about as dimensionally unstable a wood as there is

 

OK! thanks!