Originally Posted by
noglider
1. You are doing it wrong.
2. You should get better patches and glue.
3. No, patches can last indefinitely.
Let the glue dry! Err on the side of too long. I once forgot I was in the middle of patching (at home), and hours later, I applied the patch. It worked great. You shouldn't need more than five minutes, but if you're in doubt, wait longer.
Rema patches are the best, though I am usually successful with other brands, including no-names.
Rema vulcanizing fluid is MUCH better than the others because it makes a chemical bond that makes the patch and tube intertwine at a microscopic level. Other glues are just sticky.
When the patch is dry, the edges should not show any gaps. At that point, it is tempting to add glue to finish the job. This is guaranteed not to work. Peel the patch, clean the tube, and start again with a new patch.
You can do this. I've taught dozens of kids to do it.
+1 Always spread the glue well beyond the anticipated patch edge so there is no chance of unglued edge. I always put two coats of glue on, drying between. On the road, I don't always wait the full 7 minutes but often there is wind that speeds things up. I do look to make sure the wet shine is gone.
To follow up on cycoccommute's comments, yeah my tubes get a few patches. Not 30 but 5-6 typically. Even at the high local price of 25 cents/patch, that's coming out well ahead. I patch on the road almost always. I ride on radial tire steel wire roads. So I get a lot of flats from wires barely thicker than hairs and only an 1/8" long. Very hard to find in the tire tread. But when you install the patched tire, you know exactly where the problem is; at the patch or exactly the same distance from the valve in the other direction. (And that tiny wire WILL, if not removed, cause another flat. Or two. Or three.)