Transom layup

[pelican]

Originally Posted by lelandtampa

So i just bought a 78 20' MA and it needs a new floor and transom. Here is how i plan to layup the new transom. any thoughts would be appreciated.It will be all epoxy resin and engine will be transom mounted.

OUTSIDE TRANSOM SKIN
LAYER OF Chopped MATT AND RESIN TO FILL IN GRINDING GAPS
DOUBLE 3/4" MARINE GRADE FIR PLYWOOD laminated with epoxy putty
1708 ACROSS THE TRANSOM TABBED 2" TO HULL
1708 tabbed 4"
1708 tabbed 6"
1708 tabbed 8" repeat with 1708 (until factory thickness of inside glass is built up)

chop strand matt and epoxy doesn't play well together...epoxy and gel coat - it can be done,but....


using wood core - the holes will require overboring,filling with a thickened epoxy,then having the holes drilled through the epoxy - to protect the coring from water intrusion.water intrusion into wood is never a good thing.plywood will absorb water,like a sponge."saltwater preserves wood,freshwater rots wood" -


using a composite board,like Penske board/coosa board avoids all that and allows the use of polyester compounds to laminate;along with the composite being a dense foam,with glass fibers on the outside,this composite will absorb nothing,weighs 45%less than wood and it will last indefinatley


there's other options sir....including a half ceramic/half Penske/coosa board transom core - lots of manufactures use that approach,which seems to work out very well