A few months ago I had a problem with a punctured Slime-filled inner tube that I couldn't fix with a patch so I had to vulcanize it.
However, I had the same problem a week ago with the rear tube as well and tried to find a tyre shop in Zambia that could vulcanize it. Didn't find one but instead I found a good tyre shop that says they can patch it. And they did, cleaning the puncture area with hexane and using Tip Top's Blue Cement. That did the job! 1000 km after putting it back on now and it hasn't started leaking. So I think it's gonna hold.
Nice thing about it was that they did it for free because we weren't sure about the result

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Jami