This was back in the day when there were full service gas stations and friendly gas station managers.
Full service stations.....remember the uniforms (and the HATS!!!!)
Oh cool, I'm not the only ol' fart on the forum.
I use to do this on my old tubed street bikes and I'd use the heat patches (Sears I think) that needed a clamp and had a a tray with dry fuel attached to them.
I had to clamp them to the tube, ignite the fuel and sort of melt the patch onto the tube. Let it cool and slowly peel the tray off the patch before stuffing the tube
back into the tire. I never had one leak. When I switched to dirt bikes I quit leaving the wheel on the bike because I had more trouble with the knobbies and I'd end up
pinching the tube and making a second hole to patch.