water in tubes

[luvthelake]

hi, i have a 1994 24' grumman toon that i just recently bought. it seems that there is some water (not much but you can hear it sloching around when the boat is on the trailer) in one of the tube sections. there does not seem to be a drain hole only a hole with a plug on the top of the toon. when the boat is out of the water there is no leakage that i can see out of the section in question. how should i go about locating the hole and how can i fix it? also any ideas on how to get the water out?
thanks

 

[Silvertip]

Re: water in tubes

Get the water out by sucking it out. Remove the plug, raise the front of the trailer, insert a small diameter tube and siphon the water out. You can by refrigerator ice maker or clear vinyl tubing at any home improvement store. Vinyl is a little more flexible so use it. You might even add some weight to the tube so it falls to the lowest point in the chamber. Any hobby shop that sells gas powered model airplanes will have what's called a "klunk". This is a metal fuel pickup that you can simply add to the end of the tube so it falls to the lowest part of the tank.

 

[5150abf]

Re: water in tubes

Short of drilling a hole(not recomended) I think Silvertip is right on with how to get the water out.

As to finding the leak you will need a small amount of air(6-7psi or less) and some soapy water and a spray bottle.

Put air in the tube and spray away till you see bubbles, check the whole tube, alot of leaks are on top of the tubes and as water flies around under the boat it will get into the tube.

We actually use Palmolive dish soap at Bennington.

 

[rrhodes]

Re: water in tubes

Just as a heads up if I ever have to do this. What is the danger point with air pressure in the logs? I have read somewhere that you should only use 3 or 4 psi and that 7 would damage the log. (Note: I am not questioning you, I am by no means an expert) Just want to make sure I never get near the breaking point.

 

[wildbillhemphill]

Re: water in tubes

I have an old Pontoon its a 76 model and had a lot of water in the pontoons.
after doing AIR tests on them and finding no leaks I siphoned the water out.
Now keep in mind that this boat stays in the water year round after 2 years I had to pull it out for a motor change and had water in the pontoons again (not nearly as much) and after speaking with several dealers and manufacturers I found that they do accumulate condensation in them so I drilled holes in the rear and welded stainless couplings and now I have drains on the pontoons

 

[Splat]

Re: water in tubes

Agree with it may be only condensation.

It's also not uncommon to only get some water in one pontoon especially if the boat is docked, the tube near the dock typically sees less sun and thus less temperature change. Thus less condensation.

Bill

 

[lots of boats]

Re: water in tubes

Hi

Just to add a bit to has already been said about the 3-4 psi limit when pressure testing. This IS the limit, over that and there is a risk of popping interior baffle welds, tearing plug welds out and splitting deck plates if there are any. We test welds with a dial guage on a 1/4" pipe thread T. You thread the T into the hull, probably on a bushing, and one side of the T has the guage, the other side has a ball valve and an air fitting. You add air and watch the guage, when it hits 3psi close the valve and slop lots of palmolive soapy water all over the the place. Then wait. Pinholes make frothty slow growing bubbles. Cheers.

 

[5150abf]

Re: water in tubes

It is REALLY hard to find leaks in a built boat because you can't see most of the tube.

Had boats at work that you drain water out of but can't find a leak, we normally pull the tubes to get them completely checked.

The majority of welds are on top of the tube which you can't see.

Check the front of the front brackets and the back of the back brackets really well,these are stress points and it isn't uncommon for them to crack at the weld end and as you drive the boat water splashes on top of the tube and goes in.

Also the top seem at the joints , you have 4 welds converging and get alot of leaks here.

I have never actually measured how much air we put in tubes but think it is somewhere around 8-10 psi but then again if we blow up a tube I just build another one and if that tube can't take 10 psi I don't want it in the feild on someones boat so it is kinda of a stress test.

Also we have multiple hoses so all sections air up at the same time, doing one section at a time would lower your top pressure.

 

[CharlieB]

Re: water in tubes

it may be only condensation.

ANY water accumulation more than a few drops is POSITIVE PROOF of a leak.

If moist air can get in to cause condensation, then there IS a leak. PERIOD.

It is REALLY hard to find leaks in a built boat because you can't see most of the tube.

I have never actually measured how much air we put in tubes but think it is somewhere around 8-10 psi but then again if we blow up a tube I just build another one and if that tube can't take 10 psi I don't want it in the feild on someones boat so it is kinda of a stress test.

Also we have multiple hoses so all sections air up at the same time, doing one section at a time would lower your top pressure.

As an independent I don't have the tools to 'build another one' (I WISH) so I'm have to be more careful with customers tubes. I use a low pressure regulator set to 3 psi.

I really LIKE your method of multiple hoses, allowing more pressure without flexing interior chambers walls, 8 or 9 psi should make more bubbles and really help to find a leak.

 

[5150abf]

Re: water in tubes

That was kinda my point is I can get away with it but for the normal guy your method is best, better safe than ordering a tube.

At one point were making 60 tubes a day so alot of hoses is the only way to do get it done, I have 3 air check stations too, port-starboard and final so all our tubes are checked at least 3 times and as I said the increased pressure is also a quality check, big pressure finds weak welds pretty quick.

And I agree, if you can here water in the tube it isn't condensation.

 

[asdasc]

Re: water in tubes

I read this with interest, along with the sticky on the burst tube. I have an old home made (best as I can figure) really heavy pontoon boat, and the starboard tube seams to leak quite a bit, but only to a point. When I transported it, I drained it with a siphon hose. When I put it in the water again, it listed within a weekend, but then seems to have stabilized and hasn't changed much over the past month. I was thinking about pulling the plug (it is above the water line) and adding some air pressure to look for bubbles in the water, however, I am afraid that if I pull the plug it will start to sink more.

What are your thoughts?

I plan to pull the boat out of the water for the season in another month anyway. I keep it on blocks and can get at most of 3 sides of the tubes. Does this construction prompt you to advice anything different on the leak testing procedures?

Thanks,

 

[5150abf]

Re: water in tubes

When you pull it put some air in it and get a spret bottle with soapy water and spray away.

Pat special attention to the front and rear brackes as they are stress points and have a tendency to crack.

You may luck out and see water squirting out and you found your leak.

 

[Silvertip]

Re: water in tubes

Any welding shop can weld and aluminum "bung" at the back end of each tube. Insert a threaded plastic plug from any home improvement store and drain them easily by removing the plug.

 

[asdasc]

Re: water in tubes

I will look into that. I had thought about that, but no other pontoon boats have plugs, so figured there was an issue with that.

Of course, if I can find the leaks and fix them, I won't NEED a drain plug. That makes the most sense I guess.

Does the fact that it only fills up so far give me any clue as to where the leak might be?

Maybe I never really got all the water out the first time I drained it. Having the drain plug would at least assure me that I got the water out before sealing it up.