Sealing GPA Tub

[gpa5294]

I have my GPA tub in the shop ready to begin assembly, but I have found several tiny pinholes by shining light from below. My question is what is the best sealant? 3M puts out a product that is polyeurathane based but says it is for wood and fiberglass. There is another product I have found by Boatlife that says it bonds to metal, glass, wood etc and can be sanded and painted. What have others used with success? As you know I only want to do this once. Thanks, John

[Donovan]

John,

Other than welding, everything else I believe is temporary. What I have done is acquired from Eastwood copper plates that have magnets in it that help to distribute the heat when welding up these small holes (they are placed on the backside of the area you want to weld up). I am told by my welder that the copper does not adhere and helps to distribute the heat throughout the area. If it is linear, you need to spot weld along the seam and then weld and "beat in" the metal due to the shrinking that ultimately occurs. Again, I am speaking second hand as my welder has told of the issues related to welding, shinking, and warping.

Good luck,

Donovan.

[Steve Barber]

On my tub I used POR15 to seal it. It is supposedly impervious to gasoline and other solvents when cured. The manufacturer also claims that the paint remains somewhat flexable. They have a thick version e that comes in a toothpaste type tube that I used for the seams. They also have a liquid that can be sprayed or brushed on. The paint requries several steps for preparation and topcoating and is relatively expensive. Be sure to wear gloves as the stuff will NOT come off your hands if you get some on them. I was very anal about the sealing and painting process and went to a a lot of trouble to try to get it right. I will let you know the long term results in 20 years or so!
-Steve
GPA 5510