Daniel4

I know there's probably no point but I have a bunch of old bike tubes I just don't want to throw into landfill.

The patched tubes that are holding air are installed on my bikes as I keep new tubes as spares during my ride.

But I have seven patched tubes that still leak and seem to be a bit of a challenge patching on top of patches. So I'm wondering if anybody has actually cut out whole sections of bike tubes to patch another as a boot?

2_i 

Patched tubes that leak are either a consequence of a structural issue, puncture next to the vent or damage inside the vent, or of incompetent patching. The number of the tubes that leak and the specific call for the remedy suggest that second. I would work on those tubes, treating all or some of them as the training ground, removing patches if necessary, and get to the level where all patched tubes, aside when there is a structural issue, work predictably flawlessly.

Daniel4

Incompetent patching is the most likely. So, what you're saying is that I should just remove the patches and practice instead of cutting up old tubes. Those old tubes have broken or missing stems- the result of breaking when using a cheap pump that doesn't have a flexible hose.

Crankycrank

I tried the old-tube-scraps-patch trick, and it was iffy at best. You need to clean off one side of the patch real well, then scuff it up, then use some proper vulcanizing fluid, clamp for a little while and sometimes it works. I just use Rema patches now which are permanent. I'm cheap and have extra time to spare but even for me using old cut up pieces of tube were not worth it. Maybe for emergencies only.

2_i 

Yes, if a patch leaks, just tear it off, clean up the area and put on a new one. There is no shame in stumbling - you can become a master by practice and analyzing why you failed when you did so. As to the stems, Rema even sells kits for their repair, but, in my recollection, they are for the valves in the larger, more expensive tubes for agricultural vehicles, where such a repair makes economic sense.

As to the use of old tubes for patches, as Crankycrank says, it is principally possible. However, such patches are more likely to fail than the dedicated patches. The latter are made from softer rubber than the original tubes and are tapered at the edges. That is to facilitate for the patch to expand in sync with the patched tube underneath and to prevent glued edges from peeling off. You could use a grinder to taper the edges of a patch from an old tube, but the product will likely not be as good as a commercial patch, and you will not jump over the greater hardness of the rubber than desired.

dedhed

Discussed numerous times

https://www.bikeforums.net/bicycle-m...-material.html

​​​​​​https://www.google.com/search?q=usin...&bih=617&dpr=1

Daniel4

It's inevitable someone will either remind you about an old thread or criticize you for resurrecting a zombie thread.