Metal plate

[hemi rt]

I searched this but nothing came up. I was wondering if anyone has sandwiched a metal plate between 2 pieces of marine plywood for the transom? I think that if something like a piece of 1/4" aluminum plate across the full width of the transom would help distribute the forces across the transom better. Also long as the plate was full encased (and the ply) in fiberglass/resin you would be good to go. Your constructive comments are welcome

 

[Scott Danforth]

Not worth the effort or cost. The difficulties of bonding would be a pain in the butt

 

[Woodonglass]

Cost/Benefit ratio is Just not there. If you really want to beef up the transom, build it from 12 layers of luan plywood. The 12 laminations with the added resin and glass would yield more strength than the aluminum plate. You could build it for less than $200. But even THIS would be almost Not worth the effort since a properly build 1 1/2" transom build from plain ole' 3/4" Ext. Grade plywood is PLENTY strong enuf for anything up to 200hp.

 

[StarTed]

The core tends to be a separator. It's the outside that provides the strength you need. Think about how a stud or foist works. You can drill holes in the center without affecting the strength that much. It's the edges or sides that really provide most of the strength. However, you need the separator to stay in place. Rotten wood can't do that.

 

[Grandad]

From a structural design standpoint, a flat plate doesn't give much strength for the amount of material used. Adding square tubular aluminum or c-channel would give greater strength per volume. Any "boxed" structure would be superior for strength. If you're looking to add some strength to a compromised or weakened transom, here's what I did before ultimately replacing my entire transom. I trimmed about 11" off the top of my transom, replacing it with solid plywood and scabbing the two together with 2" x 4" x 1/4" thick aluminum c-channel spanning the entire transom. A mickey mouse fix I know, but I got several years more use without pulling the engine and ultimately doing it right. When I did replace the entire transom properly, I encased the entire structure, faces, sides, top and bottom of the new plywood in Formica and also re-installed that c-channel using 1/4" ss through bolts. She's not gonna flex now or rot either. Here's a pic of temp fix. - Grandad

 

[gm280]

hemi rt, interestingly enough, there are no short-cuts to fixing your transom. If it presently is suspect, do the right thing and replace the transom with proven methods and be done with it. Even patch ideas take time. Why not use that same time to do the job right? :noidea:

 

[pro-crastinator]

Interesting.
I was pondering using a piece of aluminum as a "sandwich" layer on a wooden (home made) fixed jackplate.
Judged that there would be no advantage. Plan was to go with multiple layers of 1/2 inch ply.

Background:
(fixed) Jackplate purpose would be to achieve a lower "sit". Repowered with a tohatsu - which has a shorter leg than the evinrude it replaced (both 15" motors". cavitation during trim adjustment is what I'm looking to solve.