Why does the glue in a puncture repair kit dry up so quickly?

The cynic in me says, "So you will buy more puncture kits". I too have never been able to reseal the glue well enough to use it more than twice, and only then when I had two punctures a short time apart.

You can buy rubber cement in a bottle. There seem to be at least two kinds: the type used for cut and paste for layout (the paper based technique kind that preceded electronic publishing) and the type used for rubber repairs. You want the latter. Here's one example I found by searching for rubber cement. I tried contact cement, but it didn't work very well; the formulation isn't right for tube repair. I haven't tried automotive rubber cement.

There are glueless repair kits. See this question for more information.

I think those tubes of glue are pretty much universally the same and I've never had an issue with a tube drying up (surprisingly). Maybe try to get the tiniest bit of the stuff around the rim of the tube so that when you close it up that will dry up and create an airtight bond that will protect the glue inside. Come to think of if, that's probably why I've never had a tube dry up because I use the tube itself as the applicator.

You can buy the tubes of glue separately but they cost roughly as much as the patch kit itself. If you really wanted to buy it in bulk, you could go to an automotive shop and purchase a tub of the stuff. Regardless of the application, it's referred to as "vulcanizing fluid"

Glueless patch kits will get you home. That's about it. Not nearly as reliable as glue type patches.

I use preglued patchs in the road kit.It is one less thing to carry,they go on quickly and no need to wait for the glue to dry.

I think that repair kits are thought for repair shops where patching tubes is more frequent, so you can use all the glue before it dries up inside the tube. Smaller kits that are for emergencies include two to five patches, and a very small tube of glue, generally enclosed in a disposable case, but are not universally available.

My trick to get a little more out of a glue tube is that I pile up a few punctured inner tubes, and patch them at home, all of them at a time so I use more glue every time. Then I always carry one of these tubes in my backpack so I just change the tube, instead of patching while in the trails.

At least in My country it's easy to find only the tubes of glue, which I find curious: Is it that manufacturers know patches last longer than the glue?

Put a bit of white plumber's tape over the end of the tube before you put the cap back on. It will make the glue last for serveral seasons without drying up!

The best solution to this extraordinarily irritating problem is to use a can or jar of vulcanizing rubber cement for most repairs and to reserve the single-use tube of cement for emergencies. Specifically:

• Ride with a spare inner tube and a patch kit (with an unopened tube of rubber cement).

• If you get a flat, use the spare inner tube.

• If you get a second flat and don't have another spare inner tube, use the patch kit. Now that you've opened your tube of rubber cement, close it tightly (squeeze until the cement is showing to make sure there's no air).

• When you get home, use a can of rubber cement (more about this below) with a brush to patch any punctured tubes you brought home with you.

• Keep your used tube of rubber cement for at most a month or so. Once you've opened the tube, consider it used. You might get lucky, but unless you like being stranded on the side of the road, it's safest to put a new patch kit in your saddle bag as soon as possible.

I've heard mixed reports about whether all brands of rubber cement are vulcanizing. To be safe, I recommend buying rubber cement at an auto parts store in the tire repair section. I bought a 4 oz. can for about $8. Most (or all?) such cans come with a brush on the inside of the lid. This built-in brush makes it easy to apply a thin, even layer of cement.

Since you'll only use your tube of cement when you get two flats in one day, you won't have too many (if any) leftover patches when you throw out a tube of dried-out cement. And a brush is more convenient for patching anyway.

I had similar problem with a tube of super glue. My mother-in-law suggested that I put the tube in the freezer. I actually store the tube in a glass bottle and close the cap - to avoid contact with food. The glue never dries up. You can try the same with your glue.

1) It is correct that the glue dries out soon after first use. Many glues does that and the makers do not provide solutions to the problem because it will reduce sales.

2)All farmaceuticals today are sold with small quatities individual packed (each pill packed separately). It would be the easiest thing to do with glue. But see 1). Lars Bryndum

The problem appears to be when air gets into the tube of glue - if air is present in the tube, evaporation will take place. This air can enter the tube during patching, or from a poor seal between the cap and the tube.

I was able to get a tube of glue to last for over 2 years (and 8 patches) by following advice from the other answers here:

• Make the smallest possible puncture in the tube's foil when first opening the tube (I used a pin)
• Apply the glue and re-cap it in a single action (i.e. never release pressure on the tube, as this will allow air to enter the tube)
• After using the glue, always hold it vertically and squeeze out any air
• Squeeze out sufficient excess glue to completely seal the edge around the cap

I wanted to use the glue again last night (9 months since I last used it), and it was no longer usable, but since there was liquid glue in the tube when I last sealed it, it probably would have been usable for at least another 3 months.

One problem I experienced is that the cap split on the fifth reseal - this may have been because tubes aren't really expected to last that long, or possibly because I was being too forceful screwing it on. In any case, the excess glue sealed the split.

I peeled open the small metal tube to find some rubbery residue. I figured this was all that remains once the solvent "dries up". So I pulled the residue out of the tube, rolled it into a ball (about the size of a kernel of corn), and placed it into a ceramic egg-cup. I then added a few drops of "general purpose thinners". ( I had also experimented with other fluids, such as turpentine, acetone, metho'....with varying results). Anyway, I let it sit overnight, and next morning I was able to mash it into a "glue" about the consistency of honey. I have now used this rejuvinated glue to do a standard patch. I will see how it performs tomorrow, and share the findings.