Re: Very Slow Leaks.

On 5/6/2025 1:05 PM, Jeff Liebermann wrote:

On Tue, 6 May 2025 12:47:56 -0500, AMuzi <am@yellowjersey.org> wrote:
 

On 5/6/2025 12:42 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.
>
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.
>
If I ever get around to buying a IR camera, I could try heating the
over-inflated tube, and possibly see the air leak because of the
temperature difference.
>

Your image shows a typical inflation for tracking down a
leak. Not overly large at all.

 I was worried about the excessive stretching of the inner tube causing
the pin-hole to turn into a tear.  That won't happen if the tire is in
place because the tire prevents the inner tube from stretching too
much.  However, I didn't know how the tube would react and didn't want
to find out the hard way.
 

Teeny little holes (wire, syringe needle, thin glass shard, thorn) can be hard to find at only moderate inflation.  More air, as you show in image, distends the aperture so it's easy to feel the escaping air on one's face by passing the tube across it.
--
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971