Pontoon Leak I can not find and it takes on alot of water

[gunner33]

Hi guys I have a 99 Landau 20ft pontoon. After going out on the lake for 3or4 hours when I put the boat back on the trailer I seem to have around 10 to 15 gallons in the right hand toon and the left hand one is bone dry. There is a vent tube in the very front top of the toons I have pressurized them and sprayed them with soapy water nothing not I always have air coming out the vent hole on top I have hooked up the garden hose and filled them with water i can not find a seep anywhere. Also with it filled with water I put air in also and nothing. I just don't know how I can be getting that much water. I have replaced the drain plug and wrap it with Teflon tape every time. Anyone?

 

[rogerwa]

Re: Pontoon Leak I can not find and it takes on alot of water

It could be one of the rear brackets. When running, the brackets flexes and open the crack letting water that is splashing or running over it in the toon.

I had one do this and sitting at the dock all week would not let water in. Only after running would the toon take on water. Don't assume that the leak is underwater.

 

[The Woo Woo Kid]

Re: Pontoon Leak I can not find and it takes on alot of water

Another thing to be careful of.....If you're pressurizing the toons while it's on land, the sun can heat the toons and raise up the pressure to perhaps dangerous levels. Becareful. Hose them down regularly if it's sunny(esp. this time of year) while you're doing the tests.

 

[gunner33]

Re: Pontoon Leak I can not find and it takes on alot of water

I can not fully pressurize them because of a vent pipe that is welded in the top of them

 

[gunner33]

Re: Pontoon Leak I can not find and it takes on alot of water

rogerwa How did you find that type of leak

 

[Uncle Dave]

Re: Pontoon Leak I can not find and it takes on alot of water

A boring day, but take it to the lake and let it sit in the water without running it. That would eliminate below the water line, unless it is a flexing problem.
I would vote for splashing water up on a bracket as suggested by Rogerwa

 

[rogerwa]

Re: Pontoon Leak I can not find and it takes on alot of water

I took it to a welder who pressure tested them and found the leaks. I never would have guessed as you could not seen anything just visually inspecting.

 

[5150abf]

Re: Pontoon Leak I can not find and it takes on alot of water

There should be multiple sections of tube, you need to test each section separately.

I don't understand the "vent pipe", could these be small bungs welded into each section, that is where the air should be going in.

And do be careful putting air in the tubes, the make very nice bombs at a certain pressure, you do not need more than 2-3 psi to find a leak, especially one as big as you have, 15 gallons in 4 hours is a fairly large leak.

Get access to each section of tube and test them individually , pay special attention to the top back and front of the tube, very common for brackets to crack there.

 

[gunner33]

Re: Pontoon Leak I can not find and it takes on alot of water

Well I was feeling froggy yesterday and decided that I was going to find the leak so I removed the whole toon from the bottom of the boat and I found the leak It was a crack on the bottom I never could see it because it was under one of the support boards of my trailer. My next question is this is on the bottom on the rounded part whats the best fix I am sure I need to weld a patch over it but what do I seal the crack with first? Something that will take the heat of the welder around it? Photos can be seen at

https://www.icloud.com/photostream/#A1Grq0zwJFHdFz

 

[Jeep Man]

Re: Pontoon Leak I can not find and it takes on alot of water

My concern now would be how it happened. No sign of a hit, gouge, or dent. Not a normal location for metal fatigue. I would check for other potential weak spots.

 

[5150abf]

Re: Pontoon Leak I can not find and it takes on alot of water

Late the party but you will be fine with a plate over the entire leak but you want to drill a small hole at both ends of the crack, this will keep it from cracking more and what Jeepman said has a lot of merit, that is a very odd place for a leak if you haven't hit anything