Tubes cost about five bucks. If you are spending more than 10 minutes trying to patch one, you're wasting money. Performance had tubes on sale for 2 for five bucks last time I was in there. Stock up on several of the size you need. When you get a flat, find out what punctured it and remove that, then put in a new tube. Put your old tube aside until you have a chance to patch it. Once properly patched (and that's a 3 minute job if you know how to do it), they're as good as new.