PDKL45

Like the title says, I'm interested as to what goes on when you patch a tube. I had a puncture while commuting just yesterday, a tiny piece of glass that remained in the tire after my first check and punctured my spare tube about 5 kms later, near work (thankfully). I had to buy a puncture repair kit at lunchtime and sit by the river after work, thoroughly checking the tire, extracting the tiny 1 mm x 1 mm piece of glass in it, patch both tubes--as well as a snakebite puncture caused by my own clumsiness--and finally ride home.

So does anyone know patches actually work? It's just for the sake of knowing, really. You buff the tube, put on solvent goo, allow it to dry, peel off a patch and apply the patch to the now dry solvent goo. Someone was saying somewhere that the patch becomes part of the tube? Does the solvent work to "weld" the patch to the tube?

JoeTBM 

Rather then repeat this other latest thread, a little search and you would have found it as it was very recent

https://www.bikeforums.net/bicycle-m...ube-patch.html

cyccommute 

Only some patches become part of the tube. It’s a chemical process that requires a sulfur containing compound in the patch and an activator/accelerator in the fluid. When they two are placed in contact, the activator starts reactions that cause the sulfur compound to bond with itself and the rubber in the tube. The two chemicals have to be kept separate for obvious reasons. The solvent is just there to make the application of the accelerator easier.

Only one bicycle patch kit…the Rema TipTop… that I know of has actually uses this kind of chemical bonding. I’ve checked many MSDS listings for various patch kits and the Rema is the only one that lists an “amine” in the ingredients. All the other one list solvent and rubber.

Bad patch kits…the vast majority of them…use rubber cement as a contact glue to hold the patch in place. The contact is relatively strong but it’s not a chemical bond and is less permanent. They tend to fail far more often than the Rema, even when you prepare the tube properly.

PDKL45

Thank you very much, that's exactly what I was looking for.

MrWasabi

What's everyone's favorite patch kit to get?

10 Wheels

They Work.

rydabent

I use Park glueless patches. I have had some last 3 years or more. The trick is HOW to use them.

Geepig

Last week I had to patch a tube - the first time in about 35 years. Someone borrowed my 20" bike wheeled trailer and overloaded it. Luckily the biggest patch in the kit covered the tear in the tube. And it was pouring with rain at the time.

HTupolev

Velo-Orange used to sell Rustines patch kits in the US; The safety data for Rustine's "Dissolutin" fluid lists tetramethylthiuram disulfide, which leads me to suspect that they're trying to accomplish something beyond plain rubber cement. I didn't have any trouble with those patches, although Velo-Orange has since switched to Rema.

Yeah, Park GP-2 is good stuff. Takes up no space, weighs nothing, easy to use, and seems to work very well despite being a glueless patch.

Lazyass

I tried glueless patches years ago and they sucked. Almost got me stranded once. Last year I decided to give them another try and bought some Slime Skabs when I was at walmart. They're actually outstanding, they stick well and stretch out like they should. I keep them in my saddlebag but when I'm repairing at home I still use traditional glue on patches.

cyccommute 

I haven’t ever run across Rustines. German marketing vs French? Yes, they appear to have put the sulfur compound in the fluid. I suspect that the amine is in the patch. I suspect that’s a way to get around patents as Rema puts the sulfur compound in the patch. It would also mean that a user would have to use their fluid and patches to make the chemistry work.

PDKL45

Thanks again for the tip regarding Rema Tip Top. I actually just found them here in Korea for about US $4.00, a couple of dollars cheaper than the Godawful bargain basement one I had to buy from the budget bike shop near work. I'm going to order a couple.

Bill Kapaun

When using the glue, make sure you squeeze a bit of glue out and then put the cap on the tube.
An air bubble will cause the glue to dry before its time. Better to waste a couple drops of glue than the rest of the tube.

Make sure you let the glue dry before applying the patch.

cyccommute 

This is an old myth that needs to be put to rest. Air inside the tube of cement isn’t going to cause the glue to dry out. There is a limit to how much solvent can be carried in air in a closed container. The amount of air available and the amount of solvent that it can carry is tiny compared to the glue. In a 225mL can of Rema vulcanizing fluid, the amount of solvent that can be carried in a nearly empty can is on the order of micrograms. In a tube of glue, the amount of solvent in the air bubble is going to be orders of magnitude less.

Tubes of glue can certainly dry out but the mechanism of that loss of solvent isn’t a bubble inside the tube. Not putting the cap on tightly enough is probably the most common. Other things can go wrong, however. Simply squeezing the tube can crack the tube and allow the solvent to escape if the tube develops cracks. Rolling the tube can cause the metal to crack and cause a loss of solvent. But a bubble inside the tube won’t cause it to dry out.

sch

While vulcanizing patching is the 'best' way to patch, rubber cement such as slime sold in 8oz cans and a box of Rema patches ($17 for
100 patches) is good for 10-15 yrs of patching and rarely fails. The only fails I can recall are tubes with star shaped holes usually from
side wall blowouts or holes next to larger than usual mold ribbing or in the cross hatch area some tubes have. Although I have about
30 small tubes of patch cement from a batch of kits I got for $0.50 each from lamented Nashbar years ago I no longer use or carry these.
On the bike I have two good tube spares, a pump and take the rare on ride flat home for repair there. Park no glue patches in the '00-10
time frame got you home but never held air. Haven't tried them since as Rema batch patches are all I use.

Bill Kapaun

All you need to do is plug the nozzle! The rest of the contents become moot.

cyccommute 

Including a bubble of air.

Bill Kapaun

Ignore list

cyccommute 

Your ignore list must be huge.