Patching An Inner Tube

You never want to see this. That tire looks a little flat.

I got home from my ride about three hours ago and it was fine then. The evidence points to either two things, A total blow out, or a slow leak.

By putting air in the tube I was able to determine it's a slow leak. I'm also able to find the leak, and most important, its relationship with the tire since I installed the tires with the pressure rating above the valve on the drive side (Right Side).

In other words I can see where the puncture happened in the tire so I can see if any small piece of glass, screw, nail, or whatever is still in the tire. As you can see the cut marks in the tire and tube are a mirror image, and I can see it was a small piece of glass, it even made it through the protection strip. For commuting I highly recommend paying extra for tires with a protection strip. The technology has changed a lot lately, Manufactures can add the strip, while maintaining a lot of the tires compliance so it doesn't ride like a brick.

If I was on the road, I would have replaced the tube. As you are going to see patching a tube on the road involves time and patience. Along with my spare tube bag I carry stick-on/glueless patches in case I have more than one flat, but they are not as reliable as the vulcanizing patches.

Since I'm home, and the hole is small and not where a bunch of seams are, in an open position, I should be able to patch the tube no problem. Why waste a $6 tube when I repair this with a .25 cent patch.

The first thing I need to do is get my patch kit, alcohol pad, baby powder/talc.

Find the hole, then sand a spot bigger than the patch. Sanding the tube gives it texture that allows the patch to adhere better.


Now clean the area with alcohol and let dry.

Now apply the "Vulcanizing fluid". This glue/chemical melts the patch to the rubber tube, but the trick here is to have patience. Apply sparsely and let the fluid dry for about 15 minutes before putting on the patch. This is the reason most attempts fail. I know...how is the patch going to stick, if the glue is dry, but that's just it, it's not glue....it's Vulcanizing fluid (Affirmative Captain).

A trick here I do here is, after I put the glue on, I put air in the tube so I get some bubbles on the hole. The bubbles mark the hole so I can make sure the patch will be centered.

After making sure there is no air in the tube, I apply the patch and press down on it from the center to the sides to make sure the patches surface is 100% adhered.

 Now it's time to weight and wait. I'm going to sandwich it between two 10Lbs. weights. and wait 20 minutes to let the fluid  do it's job on patch and tube. 
Be sure to peel off this top plastic. If the glue did it's job, you shouldn't take the patch off with the plastic. Be easy with this step.

I add baby powder/talc to the inside of my tubes, this allows the tubes to slide inside the tire independent of the tire for when your wheel encounters imperfections in the road. In other words it make it more compliant. I and others have also noticed less pinch flats. Some will tell you that you don't need it, and there is no science behind it, but the reality is you get less flats. 

I also smear some powder on top the new patch to let it slide as it inflates. It also helps it not stick to the tire.
Since I'm not going anywhere soon I will take extra precaution and just inflate the tube to 35psi. This will sandwich the patch between the tube and tire and let it setup in shape. I suspect you could go ahead and inflate it up to 100 psi if you wanted and not have a problem, but everything has it's weak spot. So if there is a bit of patch not setup, do you want 35psi, or 100psi behind it? Since I'm not going to ride for another 10 hours I'm just going to wait till morning. 35 psi is enough to tell in the morning if there is a leak.

One last thing. One thought about the Presta washer/nut. Some people insist you use it. I fall on the side that doesn't.

My thought is since the washer/nut holds the valve in a rigid position, and if you hit a pothole, jump, or bunny hop and deforming your tire, you could tear the valve from the tube if you hit it just right. I've seen a lot of valves pulled from inner tubes, how doesn't this happen? I've never done it in my experience.