why are transoms not rebuilt this way?

[basspirate]

i'm gonna redo my transom with nidabond but I was wondering why transoms are not replaced in the following manner:remove the entire cap from the transom, drill out and scrape out all the old wood the same way you would for a pourable transom then cut new plywood to the transom shape, laminate it, coat it with epoxy and slide it into the cavity. i'm sure there has to be a reason but i'm curious as to why this wouldnt work?

 

[almostblue]

Re: why are transoms not rebuilt this way?

I think it depends on the thickness of the cavity - seacast works the same way - a bonding agent with a maximum thickness of 1/4" . I think the plywood could be thinner if two pieces in a sandwich with klegecel or balsa core. In that case, I would bond the laminate first (or epoxy), and then use the thinabond only as a final bonding / filler.

Lamination can be fun - if you have a Tap Plastics store you can browse through microspheres, fillers, cloths, etc.

I have witness freeway overpass decks using 2 pound density foam as part of a concrete laminate.

http://www.aeroway.ca/Laminatetheory.html

 

[erikgreen]

Re: why are transoms not rebuilt this way?

Probably due to bonding issues.

You have to make sure that the new core is solidly bonded to the old skins. If you put wood back in and the old stuff is still wet the water will transfer and then you have a wet core again.

But what would probably work ok is to partly fill the cavity with nidacore after cleaning it thoroughly... then slide a piece of plywood in to take up part of the space before it hardened... the nidacore would bond with the fiberglass and plywood, and this would probably save money on buckets of the mix.

Of course, Nida wants to make money on selling the buckets of mix, so I'm sure they won't tell you to try this....

Erik

 

[a70eliminator]

Re: why are transoms not rebuilt this way?

i'm gonna redo my transom with nidabond but I was wondering why transoms are not replaced in the following manner:remove the entire cap from the transom, drill out and scrape out all the old wood the same way you would for a pourable transom then cut new plywood to the transom shape, laminate it, coat it with epoxy and slide it into the cavity. i'm sure there has to be a reason but i'm curious as to why this wouldnt work?

Removing the entire cap from the transom is an understatement. I poured mine because installing a plywood piece would have entailed removing the entire cap from the boat, the transom is also contoured and wider at the bottom than the top.
A totally flat symetrical shaped transom would surely be easier.