Complete transom rebuild 1973 Larson Shark

I know I have seen post after post on transom rebuilds but I am new to a project as big as this so here goes. I took is out of the boat for replacement and found the wood in the transom was completely rotten and the glass was cracked in the outline of the mount for the 115 hp Evinrude motor. There has been several cover-up repairs done so I cut out the glass and removed the original wood(2-1/2" plywood laminated together.

Here is my Plan:
1) HD Exterior Ply x 2-1/2" laminated together with PL for transom. Finished with 3oz woven cloth and Polyester resin (read somewhere it is more rigid).
? There is not enough room behind the splash-well to go any thicker - if the pics post you will see it - can I add another thickness the size of the cut out to make it thicker? Or should I go with the original thickness?

2)Can I continue with Poly and 1708 to rebuild the laminate on transom since I started with it or I was considering using 635 Medium epoxy from US Com.?

Thanks in advance for your input!!

Pics not working I'll try later!!

Re: Complete transom rebuild 1973 Larson Shark

Welcom to iBoats!

Sounds like you are on the right track for your transom rebuild.
Epoxy is much stronger than poly. 1708 Biax is easy to use and much stronger than regular cloth. I would try and stay with the original thickness but maybe consider using the 1708 biax even if I had to use a 1/2 inch piece and a 3/8 inch piece.

Check out my post on how to post your pics.
http://forums.iboats.com/showthread.php?t=410147

Good Luck!!!!

Re: Complete transom rebuild 1973 Larson Shark

The 635 by US Comp. is a thin epoxy, do I need a thicker epoxy to build up the outside layer of the transom where it will be done on the vertical?

Re: Complete transom rebuild 1973 Larson Shark

Nope the 635 is fine. the 1708 biax will soak up the resin and hold it. You will be making you transom outside of the boat and can coat it horizontally and then put it in the boat. Check out OOPS post on page 76 for his "Peanut Butter" recipe and use it for glueing the transom to the skin of the boat and tabbing filleting it into the sides and the hull.

Re: Complete transom rebuild 1973 Larson Shark

Trying the pics again. As you can see I had to remove quite a bit of the outer skin.

Re: Complete transom rebuild 1973 Larson Shark

New transom glued in using Fasco Epoxy.

Re: Complete transom rebuild 1973 Larson Shark

UHmmm, why did you cut the fiberglass outer shell of the boat. This is NOT the standard method of rebuilding the transom and was NOT necessary. YOu should have only removed the wood from the inside and left the outer skin. the later Strength of you boat has been compromised. You will really need to ensure that you tab the transom very securely to the port and starboard sides and then use 1708 biax mat to Re-make the outer skin of the transom. It will be a task to get it to be a smooth and pristine surface.

I'm just sayin...

Re: Complete transom rebuild 1973 Larson Shark

Too Much damage to not remove the skin. In my opinion.

Re: Complete transom rebuild 1973 Larson Shark

Used 1708 alternating with 18oz woven cloth 1/4 inch thick total. I'll post pics as soon as I down load them. You will see the new transom goes from the top outside skin to bottom covering the inside of the complete skin.