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I have a pile of old patch kits for inner tubes that are complete except for the little tube of "vulcanizing solution" that comes in patch kits. With time, these tubes crack, or have a cap fail to seal perfectly, and dry out completely. I would love to be able to buy a larger container of solution.

Vulcanizing solution appears and smells like rubber cement but I've seen suggestions that rubber cement simply contain similar solvents and/or polymers. None of my patch kits describe the chemicals in the vulcanizing solution tubes.

What is vuncalizing solution made of?

Can I obtain it in quantitites larger than a tiny tube in a patch kit? Could I make it? Can I at least obtain larger quantities of the little tubes?

  • 1
    Rema sells the stuff by the tube - several ounces for around 10 dollars. The issue is that it has a tendency to dry out, so it doesn't last super long. – Batman Apr 7 '14 at 0:19
  • Many bike shops sell both glue and tubes separately, at least in anglonesia. Sometimes for less than the cost of the same bits in a repair kit (but you don't get the instructions or sandpaper/scraper). IME larger tubes are a waste of money, the little tubes I have usually dry out rather than running out. – Móż Apr 7 '14 at 2:34
  • I would guess that the adhesive used for EPDM roofing is similar, and you can buy that in 5-gallon buckets. But as others have said, the stuff dries out so fast (once opened), you don't usually want to buy large amounts (unless you are repairing bikes for a living or or exceedingly unlucky with punctures). – Daniel R Hicks Apr 7 '14 at 2:52
  • Just buy a bunch of cheap patch kits from your local bike shop. If you're running out of patch kit materials fast, you need better tires that are more puncture resistant or tuffy liners. – Benzo Apr 7 '14 at 13:35
  • Usually, when you need one on the road, you want a fresh tube so you know it works. In any case, I patch so infrequently that its not worth the effort to keep a huge tube on hand IMO unless I was to start a shop or something. – Batman Apr 8 '14 at 1:34
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The manufacturer sells said "vulcanizing solution" in quantities of 25g tubes through 1 gallon cans, so you should be able to buy it in larger quantities. Indeed, a quick search of Amazon yield 8 oz cans (or slightly cheaper), and while I couldn't find it on something well known like Amazon there are other places that sell the 1 gallon quantity. However, as many of the reviewers on Amazon point out, an 8 oz can should be a lifetime supply, and won't dry up nearly as quickly as those little tubes.

As far as what it is, that's a little harder to figure out. Checking the MSDS, we find only that it consists of 40-70% trichloroethelyne, an organic solvent. That doesn't really solve the problem, as that's just the solvent used.

To address the question of rubber cement, if we follow your link to Wikipedia, we find that it's generally a non-vulcanizing cement, while the tire patch stuff definitely claims to be vulcanizing.

Moving on, we can think about what the traditional solution to closely held trade secret formulas is. And the tool that was designed to solve that, though only does so imperfectly, is the patent system. Maybe we can find something in a patent filing.

A quick check over on Google Patents yields something promising, Cold self-vulcanizing rubber compositions; however, upon reading the patent, it's a three part mixture, and the process involves things like "the rubber used is a natural rubber, partially depolymerized by mechanical working and peptization with diorthobenzamidophenyl." I don't know about you, but peptization with diorthobenzamidophenyl is not exactly something I feel like trying to cook up with common household substances in my basement.

Reading further on, we find some further promising patents like Tire repair with cured patch or Tire repair by "patch only" method, but they all also involve discussions of the following form:

Suitable vulcanization accelerators include, but are not limited to, thiazoles, sulphenamides, guanidines, thiourea derivatives, amine derivatives, and combinations thereof. Examples of these include, but are not limited to: N-cyclohexyl-2-benzothiazyl sulfenamide (CBS), dibenzylamine (DBA), N-N'-diphenylguanidine (DPG), Dicyclohexylamine (DCHA), 2-mercaptobenzothiozyl disulfide (MBTS).

As well as references to entire books on rubber and the process of vulcanization: 'Rubber Technology, edited by Maurice Morton, Chapter 2, "The Compounding and Vulcanization of Rubber," 3rd edition, 1987'

None of these appears to have any kind of description of a single readily available material or combination of a few that could be mixed together to work; they all appear to be fairly intricate, specialized compounds consisting of a variety of ingredients.

So I think that the 8oz can on Amazon is probably your best bet. I've heard some people claim you can just use regular rubber cement, but given that there are big cans of the "vulcanizing solution" readily available, my instinct would be to go for that.

  • very detailed answer. I'm still unclear on what vulcanizing solution actually does – deltanine Jan 5 '18 at 10:55
  • Patents are the exact opposite of a trade secret. Trade secrets are protected only by the fact that you keep them secret, and protected for as long as you can manage to do that. Patents are protected by law, but are fully public and only protected for a limited amount of time. – David Richerby Jun 17 '19 at 9:21
  • Right, the reason I brought that up is that the patent system was originally intended to reduce the reliance on trade secrets by providing legal protection for your invention or process for a limited time, as long as you make that invention public. So I wanted to see if that system had worked in this case; if there had been enough incentive via the patent system to make the composition of vulcanizing cement public, and it looks like it had worked, at least for one formulation, though you would need more expertise in the field than I have to put it into practice. – Brian Campbell Jun 17 '19 at 14:30
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The problem with a larger container would be if it didn’t seal properly and evaporated like your small tubes have before, you’d have the same problem. What you need is a stock of smaller tubes you can keep sealed.

Try searching online for a supply of small tubes (I can find 10 small tubes for $4 on eBay where I live). Then open a fresh tube each time you need some, if the previous tube has evaporated.

  • Welcome to the site. I’ve expanded the answer out a little bit and I hope I have maintained your intentions. Please use the edit option to make any corrections or add further detail – Swifty Jun 17 '19 at 9:00
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For those that are curious what the difference is between "rubber cement" and "vulcanizing fluid", here's a summary of the chemistry.

The actual process of vulcanization of rubber (Thank you Charles Goodyear) involves the introduction of cross-links between the strands of rubber through a high temperature process. The cross-links are composed of sulfur atoms, and they act to strengthen the rubber.

Vulcanizing solution does not actually vulcanize rubber. What it does is to break the bonds between sulfur atoms in these crosslinks of rubber that has already been vulcanized (for chemists out there, it's a reduction of disulfide bonds). In the presence of oxygen, the bonds between the sulfur atoms slowly reform and restore the crosslinks. If new rubber, such as a patch, is in contact with the old rubber and has exposed sulfur atoms, new cross-links can be formed between the old and new rubber. The result is a true (covalent) chemical bond between the inner tube and the patch. This is called "cold vulcanization", but shouldn't be confused with true vulcanization.

In contrast, rubber cement is simply rubber polymers in a solvent. When you use rubber cement, the surface polymer molecules of the rubber get tangled up with the rubber molecules in the cement as the solvent dries, but there is no new chemical linkage (by which I mean a covalent bond, chemically speaking) between the molecules.

For most applications, both methods generally work fine for patching an inner tube, but the cold vulcanization creates a stronger bond.

  • I have found generic rubber cement to not work well at all, It has always left my tubes with slow leaks and if stored folded up in the box the patch tends to peal off and become useless. – Qwertie Jun 18 '19 at 2:12

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