Leak in pontoon, I Think

[JDOUG]

I have a 2007 Starcraft 24' pontoon, with a 90 hp 2 stroke. The boat is always trailered and stored indoors. It has the red plastic plugs on the lower back side of the pontoons. I changed the plugs, but always get about 10 oz to 3/4 of a gallon out of the left toon. When i open the plug, i almost always get a woosh of air coming out. I pressurized the log to 1 1/2 psi, using a manifold i made up. After a week, still had about 1 psi in the log. I did notice at the sand bar one day what i thought was a air,(squealing sound) coming from the back of the boat, but i couldnt identify where it was coming from.
Could the log just leak when the boat is in the water, and not on the trailer?
Thanks

[ronb]

A couple thoughts..
Condensation from the air compressor? (probably not that type of quantity)
And to your question:
Could it leak when on the beach but not on the trailer?
Yes.

If you think about how the pontoon tubes are sitting and what types of pressures are being exerted on them, when on the trailer (you didn't mention bunk or scissor) the pontoon tubes are either fully supported (bunk) or not supported at all (scissor). When you are beached the front (nosecone) of the pontoon will be pressed hard against the ground causing a stress point and there could be a crack that is closed when the pontoon tubes are fully (or un) supported but when the nose cone is taking pressure it could 'open up'.

I'd suggest taking along a spray bottle with soapy (biodegradable) water (and some extra soap) the next time you are beached start spraying down the tubes, if it is blowing bubbles you have identified the leak.

The weird part to me is if the tubes are still pressurized (my South Bay recommends 3.5lbs) how does water get in?

-ron

[JDOUG]

It is on a bunk trailer. Not beached at the sand bar, still in 3 feet of water. Water came out before I hooked up the copmpressor. The air pressure thing is waht confuses me. both logs exhale the same amount of air when i open the plug, but I only get water out of the left tube. Its not much, but its geting in there somehow.

[Bamaman]

If you're getting water in one toon and not the other, it's just a little more than the tube sweating. You probably have a pin hole size leak--very, very small.

Like was said, pump the toon up with air and spray soapy water on the welds. Look for bubbles around the stern.

It should be an easy fix when you find it. Some people have even fixed tiny holes with JB Weld.

A leak could happen to anyone with a boat--new or old.

[dockholiday]

Had a similar problem with my first toon. Rigged up a gauge and pressure tested at 4 psi for a few hrs. It didn't seem to move the psi gauge. Must have been a very small hole and never did find it. Not sure what increments you gauge has but maybe if you had a 10 or 5 psi gauge the increments would be more defined.
doc

[JDOUG]

I used a vacume gauge I had in my toolbox with a positive 10(or 15, i cant remember) psi scale on it. I only put 1 1/2 psi in the log, becaue of all the warnings I read on this forum about not puttting more than 2 psi in. Like I said, it held 1 psi for a week. I will make sure i have a soap sprayer next time we go to the sand bar and see if I can find anything. Probably nothing to worry about, but the woosh of air thing confused me. I figured if I was getting air coming out when I opened the plug, that meant it couldnt be leaking.

[GregF]

The air coming out means it is not a bad leak but I have had minor leaks that only opened up when I was under way. It would still hold air sitting still, enough to "whoosh" when you pull the plug.

[The_Hellbilly]

I've got a slow leak again. Had it since last fall. Every few weeks I pull the plug and drain the water out. Sometimes there is a little, sometimes alot. I have closed cell foam filled logs and 3 of 'em so I really don't even notice it until it gets really full. I plan on getting it fixed this fall after lake season.