My pontoon boat on our lake at our deer lease has a leak in one of the pontoons. How do you find the leak to repair it? I was thinking thread and tap a value on it, and pressurize the pontoon and listen/look for an air leak. Any suggestions?

Do that but leave it in the water look for bubbles.

Do I win a free box of shells

You can do that, but use very little pressure. Like, hand pump pressure. Then a spray bottle with a little Dawn in it. Start at the seams, they take the brunt of dock bumps, tree bumps, etc.

That is why I did not buy one of those. Back seams is my guess.

Pull it out of the lake and fill the toon with water....you'll find your leak.

Clear flex a seal.................30 cans should do it.

Pull it out of the water. Let the toon dry, I bet it jumps out at you.

Hold it under the water and look for bubbles

That's what I was thinking! Thanks!

I think you would have to weld something on the pontoon to thread and tap first. Not going to get much threads in thin wall aluminum.

that

Fill them with water and wait for the leak to show its self. Atleast it sounds reasonable

Back when I had my fab shop, friend of mine had a slow leak. Tigged 1/4" fitting in pontoons (done both in case he had another later on) and ran 5 pounds of air in. Sprayed with diluted soap.Found his in a weld. If you do this don't let air pressure get away. They make a hell of a noise when they rupture. Boom!

Gets my vote

Sell it, and let the new owner find it.