Air bag repair

[Riverken]

Apologies for for reopening this well worn subject. I'm hoping there is some new technology for dealing with leaky air bags. I know the traditional methods using soapy water and so forth. They are time-consuming and work only moderately well. What I'd like to find is something you can put into the bag and which will seep out through the pin holes and show you where they are. Is there such a thing?

Or, it there something that will seal the holes from inside, similar to that stuff they use on truck tires (and also Shredders)?

[ohioboater]

I suppose you could try Stan's sealant. It's a latex milk that mountain bikers use to seal tubeless tires. Stays liquid inside the tire but cures when it seeps through a puncture (or through the pores on a non-tubeless tire being run as a tubeless).

No idea if it would be compatible with airbag material, or how much you'd have to put into an airbag.

[ezwater]

I just blow the bag up in a quiet room and listen, feel for escaping air currents. Small leaks can be sealed with Seamgrip without a patch. Larger leaks can be done with a patch and Aquaseal. I put two old Voyageur bags back into service after patching *many* leaks.

[Einar]

Looking forward to hearing of a better technique... but living with Moderately Well. Just blew up my drysuit this morning with 12v air pump, soaped it, and slathered on more seam seal. Kokatat owns the inside, I own the outside. And it looks like crap.

But when I'm scrunched down in the hull no one one notices.

Thinking of warmingg up some seam seal overnight on top of the house water heater for max viscosity and then dumping in the whole tube into an "stale dated" inflated Voyageur bag and slossing it around. Why not, a cheap try? Most of the wear holes are on the top side from under inflated flapping on shuttle.

[JimW]

I blow them up dry and listen, getting your ear close to the bag and you will often feel the tiny jet of air on your face even when you can't hear it.

Also look for the corners inflating, a couple of of us have found that where there is a doubled over section outside of the seam with the eyelet for tying the bag into the boat, the seam has been letting air out into that doubled up section. Mat and I fixed ours by manoeuvring the seam to the dump valve and applying aquasure/seam grip to the inside (and then blow the bag up again to make sure the skins don;t get stuck together). Sounds much easier than it is!

[ezwater]

Good point, JimW. There are any number of seam terminations or corners that may hide a leak.

Also, if one drives around with bags flopping, the stress may separate the cloth from the urethane. I have been able to fix some such by painting the cloth with Seamgrip.

[Paddle Power]

Thanks for reopening Riverken, I've been looking for air bag leaks without success!

In fact, I just tossed the bag back into my canoe as I've tried listening, feeling, soapy water on the outside, and visual inspection all without finding the leak.

I'd also seeking a better detection method.

[cheajack]

I think Jeremy Laucks at Blackfly had the best idea. Put a small amount of soapy water inside the bag; inflate it and roll it around looking for the place the bubbles escape.

[Kelly-Rand]

Let me posit a theory based on my experience.

My open canoe which I gave up years ago I kept the bags inflated year round and that was for at least 7 years in a row. I never had a leak. These were vinyl voyager bags. They stayed in the boat through freezing NE winters and still had air in them when I returned to boat in the spring. I have been C1ing for 12 years in my Atom with the same bags that I leave inflated year round and all but one has leaked. The bags that have leaked are the ones that I deflate, fold and store. Some are voyager, some are NRS and others I don't know the make. So my conclusion is not to deflate my bags, at least not in the cold months. I do occassionally deflate the bags to clean the boat but very rarely.

So my theory is that constantly deflating, folding and storing and then reinflating causes the greatest ware on the material.

Has anyone had the same experience?

[Trex]

What cheajack said. Jeremy's method works great. If you start with a dry air bag and carefully pour in the soapy water it even works for multiple pin holes. Fill it with air and rotate the bag around. The biggest hole will start to blow bubbles but if you wait a while and have more leaks you can see smaller spots that get wet and turn a darker color.

[ezwater]

Only my older bags have dump valves where soapy water can be easily inserted.

And, once you have the inside of the bag soapy and wet, doesn't it delay the Seamgrip or Aquaseal application somewhat?

I think some of you just lack sensitive cheeks.

[Paddle Power]

How much soapy water do you suggest to put inside a 48 inches end bag?

[Trex]

1 or 2 cups should do it. You just need enough to coat the whole inside of the bag. No need to make a water balloon.

[hazardharry]

when they leak i throw them away. my bags will last a couple years without any thought. if it leaks out it comes and a new one goes in to take its place. i never deflate them. at $6 per bag 6 bags per boat i can do this. now as for the leaks in my hull...

[milkman]

I have a set of airbags I have not been able to find the leak on. Usually if it's a pin hole I can hear it and feel it with my hand or lip. I decided to try the soap inside the bag method described in this thread. Here's a video of the results: http://youtu.be/5fVCubzj0wA

The method works great. And it shows me that seam leaks can be sneakily quiet. And deadly. Both the bags had the same seam leak. Both were bought this year. One leaked right away. The other failed a month later. I'm not sure how one repairs seam leaks this extensive.

I won't name where I got them from but needless to say, I won't buy from that source again. I replaced them with Harmony nylon bags which seem pretty good so far.