Tom and Wendy Hoffman
KP44 #227 (1978)
Ted and Barb Wall
KP44 #142 (1977)
The seam that causes the biggest problem is the two hull halves forward of the keel. I'm not aware of any boats having transom seal problems unless there was collision damage. Water can leak into this seam, channel along the top of the keel and pop out in the bilge many feet aft of the original leak.
The parts are glassed together from the inside, but appear to be just puttied together from the outside. Often, a real thin gel coat seam can be seen from the outside in various spots. If there is a problem in the two hull halves forward of the keel, the first indication is a wet spot on the bottom that takes longer to dry on haul out. If you remove the bottom paint, you'll see the wet seam.
I'm not aware of the transom seam being an issue or even how to inspect it other than looking since it is above the water. Even the leaks in the bottom 2 hull halves are normally only a nuisance and not a structural issue.
Tom and Wendy write:
As Ted says the seam is on the outside of the hull and is not glassed over. We had a small seep in the engine room emanating from one of the seam cracks. The seam material is white and not reinforced with glass but seems brittle and therefore cracks form. Like Ted says we waited an hour and circled any wet spots after the haulout. We fixed these spots and then after we painted the bottom on a hot day we got two more spots, I think from swelling, so we fixed those too.
The transom on Persistence didn't leak although a small section is in the water but we did have a crack there, the same situation, the seam material was brittle and cracked through the gel coat. On the inside all seams are well tabbed. As Ted says the seam is on the outside of the hull and is not glassed over.