Thread: Transom Material

Archie ... I have forgotton which boat it is!

Nothing wrong with either method so long as they can support the Donk. For runabouts etc common to see transom thicknessed around 2" (50mm). It is common enough to do the whole design thickness in ply - 2" is not going to bend much whatever the construction.

It is good to ally ply with timber because the ply will prevent the timber from splitting - much like ribs do in traditional boats.

But it will be plenty strong enough in ply alone, but built to a similar thickness.

Best wishes
Michael

Thanks for the info Mik, my boat is the Mercury 22 footer its a couple of links below i think or just check the link below.

Cheers Archie
http://s294.photobucket.com/albums/m...albumview=grid

Howdy Archie,

22ft is a fair hunk of boat ... so I would do the transom to the same thickness ,,, but you choose the material.

One thing though if it is a solid ply transom you go for then make REALLY sure you follow the normal methods for gluing the end grain (which is the ply edge of the transom.

Basically you mix up some epoxy - just resin and hardener and brush it heavily into the edge of the transom when you want to glue the hull sides and/or bottoms to the transom. Wait about 15 minutes, make up enough 'pox to do the gluing job plus a bit and mix it properly.

Before adding the gluing thickening filler to the 'pox run around the transom again with this new mix. Then add the powder to the remaining mix so it is thick enough to do the gluing and glue as per normal.

The problem you are avoiding here is that the ply end grain absorbs epoxy like crazy, so the best thing is to give it plenty to soak up before the actual gluing is done.

And note that the wet on wet process is the most efficient way - no sanding between coats!!!

Best wishes
Michael

Most boats of that scale have standardized transoms with 1.5" of plywood and of course the 'glass skins covering it. This covers outboard HP up to a couple hundred.

Since you're boat is an I/O, the transom doesn't have nearly as much loading as a big cube, high output outboard, so it can be thinner. Most of the loads are absorbed through the engine beds and dispersed along the bottom.

I've been fooling folks with what appears to be a traditional double planked, hardwood transom, for years. It's pretty much as described above. I use an inner laminate of plywood (two layers minimum) with a veneer of solid lumber facing each side. I also go to the trouble of using solid wood around the perimeter internally, so that planking fasteners don't have to rely on the end grain of plywood for a good grip. The nice thing about this type of transom is it's stable, looks like a traditional plank job, is stronger, watertight and can't wrack.

Thanks PAR thats what my plans where to use 2 layers of 19mm gaboon marine ply then cover the exterior surfaces with 5mm strips of mahogonay then as you suggested the perimter of the transom would be finished in solid timber also for looks.
I appreciate the information from everyone and have posted a few pics below of my accomplishments for sunday.

As an aside.....one of the great things I like about your shed is the dirty great white ensign hanging off the wall. Must be an ex pusser!
Rgds
An ex Birdie

Originally Posted by Dry Water

As an aside.....one of the great things I like about your shed is the dirty great white ensign hanging off the wall. Must be an ex pusser!
Rgds
An ex Birdie

personally i like the idea of the wine glass in the second pic