Couple of Question on Transom,s?

Question

I am replacing a transom on a 20' cudy, inboard Outboard, when I removed the old one I noticed the 2 sheet,s of ply were not Laminatet but Stapled, can I use Resin only and SS screws? also I know the thickness is critical, it apeared to have only 2 layer,s of cloth on the outer Skin, can I use 3 just to be safe and still be in the thickness range? the original thickness was 1 1/2" 2 Sheet,s of 3/4" ply, and I AM using Marine Grade Ply, I am a Body man of 30 + year,s so I know my way around Fiberglass,the early demise of the transon is from the amount of hole,s drilled for verious add on,s, at least 10 that were not properly sealed.I guess people use the cheepest Silacone they cay find on such a critical area and expect it to do the job.

Thank you.

Answer 1

here's the trick to long lasting marine repairs: EPOXY!! put the polyester and Bondo away for another day.glue the two 3/4 sheets together with WEST System Epoxy and Cabosill or = as a thickener, and do your glass work with WEST epoxy.

and you're right; drilling holes in ply, exposing the end grain and not sealing properly = ROT ROT ROT

best is to seal all endgrain, especially that exposed by drilling, with epoxy and then bed with Boat Life , or, if it NEVER has to come off again, 5200...

Answer 2

If the original was just stapled together & the thing was glassed over to hold it together & it lasted for a while.

Sounds like your plan is better to begin with.

Bonding the ply together w/ resin has to be as strong or stringer than staples alone.

Ply does have a little "grain" so crossing the sheets will add stiffness.

S.st. screws are just insurance.

Have seen this kind of buildup (glass over ply ) done to repair.

broken rudder skeg on sailboat & that's under water.

Not sure about the number of layers of cloth , but if it is really wetted down w/ resin ,is strong stuff.

Best regards

Answer 3

Lay 11/2 oz mat between wet with resin>s***w together>Silicone is not for boats as it doesn't hold>Fill with polyester resin and cabisile ground fibers>to make a putty>To do a better job when cutting the  hole for outdrive glass  the plywood edges so it won't rot again>

Answer 4

Yes, Resin and SS Screws are fine.

You should be fine w/3 pcs. cloth.

Answer 5

epoxy does hold up much better than polyester. You can but the less expensive epoxy and it'll still be better than regular polyester resin. Work with it just like other fiberglass materials.

The builder used staples cause they have a gun to put em in -quick and nasty.

Answer 6

yankey knows what hes talking about I've used the west systems,good stuff! BUT SPENDY!