Kabir

When should I apply the patch on the tube? When it is inflated or deflated? I just applied one when it is deflated. When I pumped the air in, I noticed that the tube underneath the patch stretch out. The patch seems to do its work well. I still wonder what is the right way to apply patch. The instruction on my patch kit doesn't say anything about it.

Thanks

qmsdc15

If the hole is big, you will have to patch uninflated. When possible I inflate to the size tube will be when inflated in the tire, then patch. Patch will hold fine either way.

lrzipris

I disagree. Patch uninflated, and don't inflate tube more than enough to hold its shape when re-installing. If you patch while tube is inflated, you may weaken the bond when you let the air out to get the tube back into the tire and the tube shrinks (but the patch doesn't).

bobo1949

Everyone has an opinion. I stretch the tube on a convenient part of the frame and apply a glue less patch. I tightly hold it in place for a few seconds then store or reinstall as appropriate.

n4zou

Tube deflated.

Drop by a pharmacy and purchase a small pack of single packaged alcohol wipes. Diabetics use them where they will give themselves a shot. These should be included with the patch kit! They're great for cleaning the tube prior to applying glue and guaranteeing excellent patch adhesion. After cleaning the tube with the alcohol wipe use the scrubber to roughen up the tube surface. Apply the rubber cement to both the tube and the patch. Allow the glue to dry and become tacky before applying patch to tube. Keep pressure on the patch and tube for at least one minute while the rubber cement cures. A properly applied patch will be stronger than the tube.

moxfyre

As most others have suggested, it's better to patch the tube UNINFLATED so that the patch won't get scrunched up and deformed when the tube is later deflated.

The rubber of the tube and patch is designed to be very stretchy, so no worry about that. The interesting thing is that when the tube is actually inside a tire, it does NOT stretch very much. It stretches until it's completely pressed up against the tire and rim, then stops expanding. This is a good thing: if you were to pump a tube up to 120 psi outside of a tire, it would explode! But inside a high-pressure road tire, no problem. It's sort of like blowing up a balloon inside a jar... the balloon will flatten itself out against the sides of the jar and then can't expand further.