I have a slow leak in my 4.2m Mode, which has been there a while. (It becomes a bit soft after a 1-2 hour session.) Today I finally pulled the bladder out and checked it thoroughly by submerging in the laundry basin, but can't find the leak. Has anyone got any better suggestions.

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taveray said..
I have a slow leak in my 4.2m Mode, which has been there a while. (It becomes a bit soft after a 1-2 hour session.) Today I finally pulled the bladder out and checked it thoroughly by submerging in the laundry basin, but can't find the leak. Has anyone got any better suggestions.

Pump to a higher pressure, this expands and opens the hole. Place in swimming pool and watch for bubbles.

Could also be the valve is leaky and not the bladder. I believe the North wings have standard 'boston' style valves (Same as Ozone)? I have had Ozone kites slowely leak through the valve because of closing the valve with a little sand inbetween. Cleaning it solved the issue.

I had the Mode and Mode Pro before. And had the same issue with a few of them.
Strut going soft after 1+2 hours.
Always the valve. Not sure exactly what on the valve, as I tried a lot of things and in the end it stopped leaking.
But I could locate it to the valve with soapy water, and full pressure in the wing.

It's a two step process. Some super slow leaks can't be detected with the bladder out because you can't get enough pressure in the naked bladder.

With the bladder in the wing inflate it hard. Get a container of water with a good splash of soap or dishwashing detergent.

Rub your wet soapy fingers along all the seams and anywhere else that looks likely. You might have to let it sit and watch for bubbles forming. It may not be instant but once you see them it should be persistent.

You can then pull the bladder out and focus on the area you identified. It may not be that exact spot but it should be in a likely place not too far away.

I used that technique for finding tiny leaks in seams I had welded doing a massive repair. It worked fine. The leaks were coming from a line of welding under another piece of material, or at the corner of a weld where a number of layers converged. They were obvious leak candidates but the air was leaking in one spot travelling to another then out.

I've had far more common slow leaks when the welded flanges of the valves would start peeling off. They're sort of intermittent because when the wing is under full pressure the flange would be pressed down hard and not leak. They only get really leaky when then peeled section gets quite big.

If the material under the flange is sound it's easy to stick with Polyurethane glue (Stormsure). Eventually the valve will continue to peel off and you'll have to replace the whole valve or the bladder.

Some holes can be very hard to find but at your rate of loss should be doable.
Spraying water+detergent (not on grass) bubbles to show area of leak. Remove bladder and repeat in leak-area, including over valve and seals and submerge in water to find hole bubbling. Some 'ghost' holes won't open up at the low pressures outside strut, so run (sensitive) cheek over area to feel flow of escaping air. Even that didn't work for me so got a magnifying glass and using a marker pen circled any marks in suspect area. I then ran (even more sensitive) eye over 20 marks and felt faint blow out of the last mark. Out of interest I submerged in water and no bubbles but sealed anyway and it worked. Under a magnifying glass the leaking hole didn't look any different from those that didn't leak so mark everything. It took several, frustrating hours.

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Gorgo said..
It's a two step process. Some super slow leaks can't be detected with the bladder out because you can't get enough pressure in the naked bladder.

With the bladder in the wing inflate it hard. Get a container of water with a good splash of soap or dishwashing detergent.

Rub your wet soapy fingers along all the seams and anywhere else that looks likely. You might have to let it sit and watch for bubbles forming. It may not be instant but once you see them it should be persistent.

You can then pull the bladder out and focus on the area you identified. It may not be that exact spot but it should be in a likely place not too far away.

I used that technique for finding tiny leaks in seams I had welded doing a massive repair. It worked fine. The leaks were coming from a line of welding under another piece of material, or at the corner of a weld where a number of layers converged. They were obvious leak candidates but the air was leaking in one spot travelling to another then out.

I've had far more common slow leaks when the welded flanges of the valves would start peeling off. They're sort of intermittent because when the wing is under full pressure the flange would be pressed down hard and not leak. They only get really leaky when then peeled section gets quite big.

If the material under the flange is sound it's easy to stick with Polyurethane glue (Stormsure). Eventually the valve will continue to peel off and you'll have to replace the whole valve or the bladder.

A small leak may take time to form a large bubble, soapy water and rubbing your hands over the area to agitate works for me. As Gorgo said, leaving the bladder in is a good move too as you can increase pressure and roughly locate the area, again soap and water. I had repeated leaks on a brand new wing, turned out a needle point had broken off and embedded itself in one of the seams.

Thank you gentlemen. Airsail, you galvanised me to pump it a bit more than I had previously dared and that showed me that a patch, that I had thought suspect, was indeed the problem. I tried to peel it off, but it stuck tight and the risk of tearing the bladder was too much, so I stuck 4 more (1 on each side of the square patch). I think that might not have been 100% but appears to have reduced the leakage. Let's hope so! WhiteofHeart: the valve didn't show any leakage when under water, so I wasn't concerned about that, but I have taken note of your advice for future reference! Thanks again!

The best and easiest way

I think that video will work for most leaks, but I've had some where the leak is literally 1 bubble every 15 seconds. No way you can detect that on your face. I agree with Gorgo. Initial detection with bladder inside wing full pressure and detergent mix. Localise leak. Extract bladder. Inflate and detergent again. Hope you can find it. I've had leaks you search for and nothing. Search over bladder again and leak becomes visible. Mark it. Search for it again and it disappears. Lots of patience required. Or just replace bladder and be done with it.

Based on my experiences... I've tried removing the bladder and the pool method etc. but it takes so long and frustrates the sh!t out of me. As a result, anything that i can't find by the valve area automatically goes to the wing guy to fix :-)

My technique is similar/same as the other said... With the bladder in the wing, detergent water to find the general area (i have a little squirt bottle for this now). If there's any bubbles (even if it's very very small ones 2+ seconds apart) within 3-4" of the valve, try screwing the valve in tighter and/or cleaning the threads and trying again. If that doesn't work, buy a new valve (or "borrow" one from another wing you have) and try replacing the screw-in top part. On 3 wings, i've ended up screwing in the existing valve so tight that it's tough to unscrew, but that's the only way to stop the leaking... On an Armstrong, they did warranty the bladder/valve on that one as it was only 1-2 months old). On 2 north wings, one i ended up screwing it in really tight and just using the leading edge valve to pump up/deflate, and the other one i bought a new valve and the screw-in part stopped the leaking.

Most of my leaks on my wings seem to be from the valve top. It's weird because the wings are clean and i don't do anything weird to the wings, it just seems to happen. But i have started doing the 'reverse screw' (e.g. go counter clockwise to feel the threads sit in properly) and then tightening the top up. I feel like that's helped.

quite the promo for parawings this thread
sitting on the floor right now trying to find pinhole in a wing bladder, not my happy place

Thanks again Gentlefolk. A lot of great tips in there!

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winduser2 said..
The best and easiest way

Agree with Marty
Rubbish for truly slow leak. You can't feel leaks in a board, whereas soapy water makes a golf ball sized sphere of froth.
if soapy water doesn't do it, your face won't.
if you still can't do it take it to a pro who sees every kind of problem and may well have a head start in suspecting where it is


oops old thread