I have never seen anyone else use the same method I use to patch tubes in the shop. After abrading the spot to be patched with sandpaper, I clean the area with lighter fluid (naptha) and then apply the cement after the solvent evaporates. According to my father, who showed me this when I was a kid, all patch repairs were done this way back when all tires had tubes. I can't swear the solvent is absolutley necessary, as I obviously don't carry lighter fluid on the bike with me, but it does seem to act like a flux. Works well with the self vulcanizing patches I like to use.