If only someone would think to include these instructions with a patch kit!

The patch kit I saw at walmart, the bell one, only had three steps I think. Rough up tube or patch with the included scraper. Apply glue. Apply patch.

hence the thread. but its cool

6. They thought they were using a hot vulcanizing patch. In olden days, tubes were patched with a "hot patch" that comprised a piece of rubber and some sulfur. the patch was clamped onto the tube, over the hole, and the sulfur set on fire. Heat + sulfur = real vulcanization. Such patches were available until a few years ago; they're no longer for sale in the US, or anywhere with air pollution laws. They did work really well, though.

cold vulcanizing stuff works just fine. (and there's no glue on the patch. The layer on the tube is quite enough. )

I'm definitely not a chemist, but I don't think it's glue in the conventional sense. I think it actually changes the chemical state of the rubber into something gooey like modeling clay. The patch itself is already in a similar state (protected by foil). Then when you stick them together, the molecules or polymer chains or whatever is in there meld together, becoming a single continuous piece of rubber (or clay). With regular glue you would still have two distinct pieces of rubber, with a layer of adhesive between them. If there is still solvent in the area, it apparently interferes with the bonding in some way.

It reminds me a little of "chemical welding" cement that is use for bonding some types of plastics, like acrylics and, I think, PVC pipe, except you don't let them dry first.

FIRE!

Yes, that was routine when I was growing up. Made patching tubes a lot of fun ... you know, kids and matches, and you could it right in front of Mom.

I don't fire them off now, though.

When I patch tubes in my shop, I finish up by putting the patch in a clamp for a minute or so. That sucker's on there!

Also, good glue makes a difference. I bought a small tub of stuff -- "Vulcanizing Fluid" -- from Rema, along with 100 of their Tip-Top patches -- bring on the glass!