1977 Starcraft Mariner 21’ Transom Replacement

[Matthew2295]

hi everyone. Thought I’d get some insight on what to do. I am installing a new transom in my sc and noticed that the rail that the transom sits in has a 1/8 or so gap from the aluminum skin. Just wondering if anyone knows if this is normal or if I need to re rivet it so it’s tighter against the skin. Thanks!!

 

[oldrem]

Having a hard time with that photo - can you take a shot from further away so we can see it in prospective?

 

[rookie456]

17ft bluefin. When you look down into the channel of mine it looks like a gap because of the bend radius from forming the Z shape in it, but the metal gets tight to the skin where the rivets are. Are the rivets holding the z channel loose, can you see a gap between the transom and the channel all the way thru?

 

[oldrem]

Could try bucking those rivets to tighten things up again. New transom wood the proper thickness. I used 2 thicknesses of 3/4" ACX ply glued together and treated heavy with OTF to get the full width of my trough. Once bolted in tight it should be good.

 

[Matthew2295]

So I check on the rivets and they are tight with no play but still a gap between aluminum skin and where that trough rivers to it. I test fitted the new transom and it’s still a very tight fit. So it must be correct then. Also any insight on how to plug old holes in the aluminum skin on the outside without drilling through holes in the the transom. Thanks!!!

 

[oldrem]

I had to plane my transom wood down slightly to make it fit snug but with no slop.

Looks like you have a combination of holes for securing the transom (which you need to do) and holes for mounting an outboard bracket. Once the transom is in and secured, I would fill any unused holes with something like Marine Tex.