Had to change out a flat, but there's no visible puncture and it's a slow leak. When I pumped up the tube to a nominal pressure (<10psi), part of it ballooned and expanded far beyond the normal tube size and expands further along the tube as I pump more. Is this normal behavior?
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Re: Latex tube ballooning [aravilare]
[ In reply to ]
aravilare wrote:
Had to change out a flat, but there's no visible puncture and it's a slow leak. When I pumped up the tube to a nominal pressure (<10psi), part of it ballooned and expanded far beyond the normal tube size and expands further along the tube as I pump more. Is this normal behavior?Yes, normal...but, I would avoid doing that since it unduly stresses that portion.
To find the leak, pump up slightly less than what causes the ballooning, and then you're going to need to put the tube under water to look for bubbles (I typically fill a small sink and then "dunk" a portion at a time until I see the fine bubbles). Latex is so well at "self-sealing" at low pressures, you may need to manually stretch portions to get it to leak if you're unsure if a particular section is the culprit.
Once you find it, dry off the tube and patch with a glue patch.
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Re: Latex tube ballooning [Tom A.]
[ In reply to ]
Tom A. wrote:
aravilare wrote:
Had to change out a flat, but there's no visible puncture and it's a slow leak. When I pumped up the tube to a nominal pressure (<10psi), part of it ballooned and expanded far beyond the normal tube size and expands further along the tube as I pump more. Is this normal behavior?Yes, normal...but, I would avoid doing that since it unduly stresses that portion.
To find the leak, pump up slightly less than what causes the ballooning, and then you're going to need to put the tube under water to look for bubbles (I typically fill a small sink and then "dunk" a portion at a time until I see the fine bubbles). Latex is so well at "self-sealing" at low pressures, you may need to manually stretch portions to get it to leak if you're unsure if a particular section is the culprit.
Once you find it, dry off the tube and patch with a glue patch.
Thanks, just disconcerting seeing that in a tube. I've never had issues with identifying leaks with previous flats without immersion testing, fortunately.
Re: Latex tube ballooning [aravilare]
[ In reply to ]
aravilare wrote:
Thanks, just disconcerting seeing that in a tube. I've never had issues with identifying leaks with previous flats without immersion testing, fortunately.Then you've been incredibly lucky in the past or not patched many tubes. With ultra slow leaks you may not even see a stream of bubbles, just a dome of air projecting from the location of the leak that will eventually escape and flat upward. You'll want really excellent light when seeking really slow leaks. After you've done a few hundred patches you'll become very expert the process;)
Hugh
Genetics load the gun, lifestyle pulls the trigger.
What do you mean by slow leak. ? Latex will seep air over a couple days