Steve Sanford
Well-known member
Trey~
I just read through this whole thread and want to reinforce one thought: It's critical that you seal the plywood transom thoroughly with epoxy before you encapsulate it in CSM and polyester resin. Most early production 'glass boats used wood for framing/reinforcing. The industry learned the hard way that polyester is not truly water proof. Water vapor can move through it an saturate the wood (esp. with condensation) and create the perfect environment for the fungi and bacteria that cause rot. So, the wood rots within its 'glass capsule. The stringers in my old 'glass sneakbox are a good example of this process. Most manufacturers use structural foam instead nowadays.
I would seal the whole transom with 2 coats of epoxy, esp. the adges. Then, smooshing it onto transom interior with ployester-saturated CSM (you probably know that epoxy is chemically incompatible with mat before it cures) is a good plan. I would then "tab" the entire perimeter with a 2" border of CSM but leave most of the interior face of the epoxy without 'glass (no real benefit). As long as the epoxy gets painted - to avoid UV deterioration - you'll be good to go.
Keep the pics and stories coming!
SJS
I just read through this whole thread and want to reinforce one thought: It's critical that you seal the plywood transom thoroughly with epoxy before you encapsulate it in CSM and polyester resin. Most early production 'glass boats used wood for framing/reinforcing. The industry learned the hard way that polyester is not truly water proof. Water vapor can move through it an saturate the wood (esp. with condensation) and create the perfect environment for the fungi and bacteria that cause rot. So, the wood rots within its 'glass capsule. The stringers in my old 'glass sneakbox are a good example of this process. Most manufacturers use structural foam instead nowadays.
I would seal the whole transom with 2 coats of epoxy, esp. the adges. Then, smooshing it onto transom interior with ployester-saturated CSM (you probably know that epoxy is chemically incompatible with mat before it cures) is a good plan. I would then "tab" the entire perimeter with a 2" border of CSM but leave most of the interior face of the epoxy without 'glass (no real benefit). As long as the epoxy gets painted - to avoid UV deterioration - you'll be good to go.
Keep the pics and stories coming!
SJS