New Old 1974 20' CC

mvhull · #1 05-21-2009, 11:16 PM

Hey guys,
I just joined the club.
I've got a 20cc 1974 with a rotten transom, what a surprise, and otherwise solid decks and cap. The hatch over the fuel tank was rotten so I stripped the laminates and will recore that as well.

I haven't cut the transom out yet, planning on doing outside because I dont want to take out the rear hatches, etc. The plan, cut out the transom with a 2" radius, clean down to bare inner glass skin, lay a layer or two of 1708 glass on inner skin?, fill perimeter area of transom with 3M High Strength Repair Filler?, add 3/4" marine ply(epoxy coated), lay 3-4 layers of 1708, fair and paint.

How does that sound?

Dilligaf · #2 05-22-2009, 12:00 AM

believe u need two 3/4in marine plys so you get 1 1/2in thickness for transom

wtenglish · #3 05-22-2009, 03:51 PM

I'm not an expert but don't believe you need additional glass layers on the inner skin, just bed your prepared core material in a thickened epoxy mixture.

mvhull · #4 05-26-2009, 10:43 PM

What kind of saw have you guys used to cut out the transom? I'll be doing an external rebuild. Circular/Jig/Router?

Also, for bedding the core plywood, it seems using thickened cabosil mixture seems to be the favorite. Then I lay 3-4 layers of 1708 on outer layer after I fair/fill any gaps, etc. Refair, and good to go.
Also, how far over the edge of the transom on the bottom and topsides should the glass overlap?

Also, what kind of epoxy are all you guys using? If I plan on using original inner skin, marine ply, and cabosil, whats the recommended type?

-Mike

wtenglish · #5 05-26-2009, 11:43 PM

I'm only slightly ahead of you on my first boat restoration project so please take this for what it's worth. I used a circular saw for making cuts to my transom since I could set the depth of the blade. There are other tools that may work better since a circular saw can be cumbersome, dangerous when cutting upside down and hard to reach the interior corners for certain cuts. May not be a problem since you are attacking from the outside.

As for the epoxy I've gone with the West System but if you read the site very much you will see a lot of debate over what people prefer. When doing my homework I went to their website for application techniques, etc.

http://www.westsystem.com/ss/use-guides/

Good Luck!