Fixing a failed patch I can't remove
 

I have a very slow leak coming off the edge of a patch. It's on too tight to pull it off without tearing the tube. I suspect I'll just discard it but it'd be nice if there were some kind of goop that would hold against such a weak leak.

You could try overlapping another patch over the leaking side.

Yup. This generally works. No "goop" that can be applied externally to a poorly adhered patch that will stop it leaking.

I've had good luck just taking a cigarette lighter, gas stove flame or something similar to carefully get the patch hot and it will come off easily but sometimes you need to take it off in several pieces. Get it just hot enough to not melt the patch or burn your skin. Clean up the spot on the tube as you would for any new patch and should be good to go.

It's worth trying before you toss the tube as unrepairable.

Get a new tube maybe ?

just sayin.

/markp

Vulcanize another patch over that edge. If that doesn't work, just toss it, not worth any more headache.

At some point it's easier to just replace the tube.

If you really are heck bent on repairing that patch, I'd opt for one of the Park self-sticky patches and "stitch" it on really well. A quarter works pretty well. One of those might be the better option for repair. If it were my tube, I'm with other posters, I'd replace the tube.

What kind of crazy talk is that?

I bin my used tubes as follows:

Straight tubes that have no leaks, verified with a water bath.

Tubes with pin hole leaks. I use tape to marker where the hole is. When I have no more of the above, I grab one of these and repair it with 100% success.

Tubes torn from lack of rim tape tubes, and damage thru the ply. These tubes have perforations up to 3/16", and when I have no more of the above, I also patch these with 50/50 success. I mostly pair these along with a finished or cracked rubber tire so a wheel is complete and the rim is protected during storage. I can't sleep at all when rims are naked.

Then there are popped tubes that are blown out gashed slashed, or valves cut because it wasn't aligned to the rim. Basically unrepairable. These become raw rubber stock to use for DIY rim tape, custom rubber washers gaskets, protecting stays for a rear kickstand install, shim for weird bells that are larger than 22.2mm handles, whatever.

When in doubt, hoard.

Patch um till the Valves Wear Out.
https://cimg8.ibsrv.net/gimg/bikefor...860fda0664.jpg

I haven't had a good experience with overlapping patches, but I have had good experiences with removing old patches with a battery powered dremel with a sanding drum attachment.

https://cimg9.ibsrv.net/gimg/bikefor...bb14da4f1.jpeg

And for patches where it's on the edge of another patch, carefully removing part of the old patch to expose clean rubber for the new patch.
https://cimg0.ibsrv.net/gimg/bikefor...1990114c8.jpeg

You could put some baking paper over the patch, then use iron (for ironing clothes) to get the patch hot, then remove it (patch glue becomes liquid once heated).
(the baking paper is just to prevent the iron from getting dirty from any glue or rubber)

You could also use a heat gun to do it.

I have some tubes that look like that. IIRC, right now, 8 patches is the most.

patch the patch.
when being 'cheap' meets cheap parts; i'd be concerned with reliability of the existing patch.

Has anyone ever used ShoeGoo? The silicone/epoxy cocktail?

A few days ago I decided to test it, I repaired a tube with ShoeGoo, cut another piece of tube for the patch, applied it wet and C-clamped it overnite until it cured.

If it works, I won't feel bad about letting them go with the spare rims that I sell (see my previous post in this thread).

Because when I see that a patched tube (patched with a real patch) works, I take it back when I sell a rim.

But a tube that was patched with another piece of tube, buyer can keep it along with that scrap tire.

https://eclecticproducts.com/wp-cont...-1-600x526.jpg

I used to do that and I thought I was so clever. Nowadays I use regular patches with vulcanizing glue because it works way better. The shoe goo method works for a while but the patch never actually bonds to the tube, so it can fail after some time. Kind of like how the outsoles of a shoe can come apart from the midsole.

It's always easier to replace the tube.

I've never gotten the self-stick patches to work, even on a fresh puncture. I figure it must be me.

I don't have one of these and am not careful enough to try it


I've done this but sometimes the tube tears instead. I think that's what will happen if I try it in this case.

This is a tempting idea but I'd probably melt the tube. And it's more work than I want to do. Have you ever done this?

I have the plumber's version of Shoe Goo. It's what I had in mind.

This sometimes work with the feathered patches. I have the thick un-feathered kind.

Yup.

Patch glue (including my favourite Rema Tip-Top) is advertised as "vulcanizing cement/fluid" but it doesn't really vulcanize - i.e. the process it creates is reversible with some heat.

Could you burn the tube if you apply enough heat? Probably. But some basic caution should let you get the job done without doing so. In my experience, a faulty (leaking) patch is best taken care of by removing and patching the tube properly. Other methods often don't hold very well, so I consider the "heat treatment" to be in the realm of "nothing to lose."

Note, just in case - it gets hot, gloves are probably a good idea.

Relja

I'm good at that - I have a storage crate full of tubes, all different sizes and states of repair, One day I'll take them all out and test them, repair those that need it and put them away neatly labeled. But I can't find the labels under all this stuff.