Re: Very Slow Leaks.

On 5/6/2025 1:42 PM, Jeff Liebermann wrote:

On Tue, 06 May 2025 10:19:59 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
 

I once bought some inner tubes that seem to have come from the factory
with leaks. (...)

 A bit more.  I didn't have enough patches handy, so I used a small
blob of automotive "gasket maker" to plug the hole.
<https://www.permatex.com/products/gasketing/black-gasket-makers/permatex-ultra-black-rtv-silicone-gasket-maker-5-oz/>
I didn't ride enough to determine how many months or miles the black
goo was going to last, but it seems like it would work on small pin
holes.  I don't recommend it for large punctures, long cuts or cracks.

Please do report back on that once you've got some miles on the tire. I take it you let it dry in place before reassembling the tube & tire? That would prevent the technique from being useful during a ride.
I've never used a compound like that for its intended use, i.e. replacing gaskets. I've almost always just used the proper gasket for whatever I was working on. A few times I've had to cut my own gaskets out of gasket paper. I'd be interested in feedback here on how well that stuff works. It looks handy.

Also, I had some slow leaks that were difficult to find using soapy
water.  (At the time, I didn't think to try the ultrasonic leak
detector).  So, I over-inflated the inner tube.  I think it's probably
26 x 1 3/8:
<https://www.learnbydestroying.com/jeffl/crud/inflated-tube.jpg>
Not only did the soapy water detect the leaks, I could hear the air
leak and also feel the air with my fingers.  Also, the normal size of
the tire is the mounted tire located behind the over-inflated tire.

I almost always inflate my flatted tubes much more than what your photo shows. I think it helps a lot. I rarely have to dunk a tube to find a hole. Passing the inflated tube close to my face usually allows me to feel the air escaping, especially if the stream hits my lips or thereabouts. Working in a quiet basement workshop (where I do most of my tube patching) also helps a lot, I think.
--
- Frank Krygowski