masi61

I need to patch a small pile of latex inner tubes I have accumulated over the past year.
I had purchased a (4 ounce?) can of Rema Tip Top rubber cement with the paint brush but the volume is less than half of when I first got it and it is too gooey to use right now. Has anyone successfully thinned it down in order to continue using it? What solvent did you use?

PS: I have a can of a product called “bloxygen” which is just a compressed gas that when sprayed into a paint can is supposed to prevent filming in varnishes. If I can get the Rema Tip Top contact cement filled, I plan to try the Bloxygen out to see if I can avoid having to throw it out when it becomes unusable.

2_i 

You can dilute Rema Tip Top Fluid with naphta available commercially, e.g., as camping white gas. Also Heptane/Bestine available in art supply store works. Finally, trichloroethylene, used in dry cleaning, but with health concerns, could be used. In my practice I found that the Rema Fluid can be diluted fine for about 6 years from the production date, but from then on it starts to polymerize irreversibly inside the can and should be replaced. This is shorter than vulcanizing cements from other manufacturers - I have one working fine after 10+ years. I think Rema puts in some additives that speed up the polymerization.

dsbrantjr

This is why I see no economy in buying large quantities of such things unless you use it at a prodigious rate..
I buy the smallest Rema tubes of vulcanizing fluid, carefully squeeze out all of the air when I close them,
......and just accept that there is a good likelihood that they will be dried out the next time and ensure that I have a fresh one as backup.
I was thrilled when Harbor Freight started offering Krazy-type glue in a package with 10 small tubes, very convenient.
https://www.harborfreight.com/10-pie...lue-68345.html
https://www.harborfreight.com/10-pie...gel-68349.html

pdlamb

You'll have to check the side of your can to see what the solvent is (it's changed over the years). It wasn't worth the cost of the solvent in my case, I got about 3-6 months more life out of the can and, like 2_i, the remainder polymerized anyway. The replacement can of Rema I bought polymerized within a couple years, couldn't be revived.

I think the can of Slime rubber cement I've been working on is six years old, and it's working out just fine. Less expensive than the Rema, no signs of in-the-can polymerization, no patch failures because of cement.

Crankycrank

Store your cans of fluid upside down. This helps seal the lid so the solvent doesn't evaporate as quickly.

masi61

pdlamb - is the Slime rubber cement usable to patch butyl and latex inner tubes with Rema patches?

masi61

Are you still able to get the lid open when you do this?

Crankycrank

I'll say that sometimes it can make it a little more difficult but since most people have some residue on the caps after the first use it ends up being about the same. Not much of an issue really.

Racing Dan

Unless you have the suggested supplies at hand, I highly doubt its worth it. Imo, just get at fresh tube of "glue" and get on with it. Getting a bazillion patches and a big bottle of glue seem like false economy as it goes stale long before you get to use it. Btw. I've use all sorts of non Rema patches (except the self adhesive type) and they were all fine, as long as I applied proper technique. - abrade around the hole, apply glue, let solvent evaporate for ~5 minutes and only then apply the patch.

cyccommute 

Naphtha or heptane will work. Odorless mineral spirits should work but it would be wise to test it…and any other solvent…on a small amount of material first.

You, and others, have a wrong impression about the polymerization of the vulcanizing fluid. Yes, there is a chemical in the can to form sulfur bonds during the patching process. That chemical is missing in rubber cement which is why Rema’s fluid is call “vulcanizing fluid”. The accelerator for the reaction is actually in the Rema patch. It catalyzes the reaction that forms the sulfur bonds but the reaction doesn’t start until the patch and dried fluid come in contact.

The fluid doesn’t polymerize in the can due to oxygen. There’s only a little oxygen introduced into the can each time it is opened and that oxygen isn’t what causes polymerization. The process isn’t an oxygen driven process. Opening the can causes some of the solvent to evaporate and failing to seal the can will result in a lot of the solvent to evaporate. Just closing the can properly goes a long way to keeping the fluid useable.

cyccommute 

Rubber cement will form a contact bond with Rema patches but it will form the same bond with cheaper patches. It won’t do the cold vulcanization process, however. The rubber cement is missing the compound that reacts with the accelerator to form new rubber that Rema’s vulcanizing fluid has.

Racing Dan

Imo, get the proper stuff. Its Not rubber cement and Its just not worth it having at patch job fail on account of saving a dollar or two. If you tend to collect flatted tubes to bulk patch, I suggest getting a fresh patch kit only when you have enough tubes to use up most of a kit in one go.

2_i 

The Rema fluid that polymerized after 6 years turned into a glut that would not dissolve even after 5 weeks of immersion in a solvent. The fluid polymerized irreversibly at about the same time in a can and in a vial in which I normally carry the fluid along in my tube/tire kit. I.e., the process was tied to the content of the fluid, not impact of air.

As to the utility of a can vs small tubes, over the 6 years I just refilled or diluted the content of small glass vials carried along. Makes much more sense to me that getting new tubes of fluid for drying out. The small vials are rigid and far more resilient than tubes.

ThermionicScott 

Those 3g or 5g tubes that come in the Rema patch kits can do quite a big handful of tubes if you do them all in the same session. Zero interest in a can of the fluid for my uses...

masi61

cyccommute - I may try the naptha since I think I may have some. Just curious if (you think) using the "bloxygen" gas might help prevent evaporation of the solvent.

pdlamb

Butyl, yes. I've never used latex tubes.

pdlamb

Same thing I saw. Without knowing exactly what's in the Rema fluid, it sure looks like there's about 50% of something that changes chemically. Rema's advertising materials don't specify where the sulfur to vulcanize the fluid + patch + tube is, and it's not a refereed technical publication. The mess that's left is about half way to a rubber eraser, which has certainly been polymerized. Is that a result of sulfur-sulfur linkages forming, or something else in the precursor that's forming some other kind of link? Not that it matters, because the resulting goop is pretty clearly a polymer, just not quite with enough cross-links to build a tire.

cyccommute 

Try it on a small amount first and pay attention to proportions. If it works, add similar proportions to the can. If it doesn’t work, you won’t have wasted an entire can of vulcanizing fluid.

The “bloxygen” is just argon. It might help but oxygen really isn’t the problem

cyccommute 

No, Rema doesn’t advertise the cold vulcanization process. That I don’t understand but Rema’s main business isn’t bicycle related and they are a very old company. They may not feel the need to advertise or their advertisement may be aimed at auto tire shops.

The technology for cold vulcanization is also very old and may not have many new papers printed on it. You’d probably need to look at something from the teens, 20s, or 30s. Most of my information on the difference between Rema’s vulcanizing fluid and rubber cement comes from looking at SDS’s and looking into the way that cold vulcanization works. This Rema SDS lists N-ethylcyclohexylamine which is a promoter for the vulcanization process. Here’s an old patent using it in a different process. I’ve also found an SDS long ago for the patch itself which contains a thiol (I think) which would react with the promoter. It’s taken a lot of study to piece together all this information over several years.

I didn’t mean to imply that the material in the can can’t polymerize. It just takes a long time without the two chemical system that Rema uses. The promotors will promote chemical polymerization but they take a long time by themselves. Working together, the reaction time is much, much faster.

My point was that oxygen doesn’t figure into the reaction. Keeping oxygen out of the can won’t make much difference partly because it is a small amount and partly because it has little effect on the reaction. The fluid is used in open air and the vulcanizing fluid needs to dry in air to work properly. In my experience, the dried vulcanizing fluid can be left exposed to air for weeks and still form a good bond.

Finally, the reason that something like Slime rubber cement doesn’t form a polymer is that it is just rubber in solvent. There’s no promoter in it and, thus, it makes a less permanent bond. If a patch doesn’t work, chances are that the patch kit is one that use rubber cement which doesn’t make as good a bond.

2_i 

I asked Rema about the shelf life of their Vulcanizing Fluid. They took my data and promised to have someone with expertise to get back to me. We will see where this goes.

2_i 

OK, I heard back from Rema. I will first summarize what they said and then draw my own conclusions.

The official shelf life of the Vulcanizing Fluid is 24 months. Anecdotal information from customers, not necessarily from the cycling area, is that they make their cans last long by keeping them oriented upside down in refrigerators. As to the small kit tubes drying out quickly after their first use, the representative suggested getting larger tubes that should last longer. The Fluid is indeed meant to react chemically with the material in Rema patches. The representative was not enthusiastic about diluting the Fluid with solvent and did not appear to differentiate between solvent evaporating and permanent bonds forming. There was also a comment there about a higher solid content in the Rema Fuid as compared to the typical rubber cements in the market.

Myself, I obviously differentiate between the solvent being gone and the permanent bonds forming. From personal experience I know that diluting Fluid that dried out works and patches glued with the recovered Fluid hold just as well as glued with the fresh Fluid. However, I also found out that the Fluid bonds internally permanently around the 6 year mark. Since I cannot afford finding myself in the field with the Fluid that is already polymerized, I will mark any new can with a note to myself to discard it past its 4 years of shelf life.

zandoval 

I know I'll get some kickbacks on this but here goes...

I have used Gasoline to thin out Vulcanizing Cement. If you add it to your container the whole batch is ruined so don't. Take a small amount of the Vulcanizing Cement and add a few drops of Gasoline. Then use it immediately. This works for traditional Vulcanizing Cement that used to have Toluene in it. Some of the more modern Vulcanizing cements may not have toluene in them but another hexane or rather aromatic hydrocarbon in them. I do not know if this one time trick will work with them.

For my bicycle carry kit I keep on small unopened tube of Vulcanizing Cement and an unopened tube of Super Glue just incase the VC is dried out. Super Glue is not a good substitute for Vulcanizing Cement but it will get ya home...

pdlamb

Since my experience is that a leak patched with Slime is sealed as well as a leak patched with Rema, this looks to me like another case of "perfect is the enemy of good enough."

The fly in that ointment is that you don't really know how long your can was sitting in a warehouse before it came to you. Hopefully no more than two years!

2_i 

My previous can had a legible production date printed on the bottom. However, on the new can I got you could only see a row of dots that looked like a remainder of what was supposed to be printed there. This was sort of funny because, on the first contact, Rema asked me to tell them the serial number of the can. I hope that with the 2-year buffer I put on I will be OK, In any case, I fully get your point about this situation becoming cumbersome.

KerryIrons

Several solvents will work, and it depends on what is available at your local hardware store. Heptane, toluene, xylene, etc. It works fine and as long as the thing hasn't gone solid, you can revive a can easily. I do it all the time and have for decades.