DannoXYZ 

We're debating semantics rather than the actual stuff itself. Try an experiment yourself with a "rubber cement" product that's sold for tyre-repair. Then do the same patching with Elmer's "rubber cement" marketed for office stationary. After a day of curing, try peeling off the patches and tell us if there's a difference in the behavior.

Most likely if you get "rubber cement" in a box or tin that's marketed with rubber patches intended for tube & tyre repair, you're getting a chemical that vulcanizes rubber (aside from some of the no-name patch kits I mentioned earlier). Since it's a solvent, vulcanizing fluid "rubber cement" for patch kits dries to nothing when smeared on a piece of paper. Elmer's rubber-cement on the other hand is a glue that sticks to two pieces of paper (interdigitation) and it will dry to a rubbery layer that's easily peeled and rubbed off later.

If you really want to, we can pull up the chemical structures and composition of these two different products if you wish.

DannoXYZ 

BTW, in addition to the office-supply Elmer's rubber-cement, I've also used SuperGlue, DAP contact-cement, Vittoria tubular glue and 3M Fastak 08031 Super Weatherstripping Adhesive to glue patches onto tubes. They all work fairly well at below insane levels of riding and have lasted me for quite a while. However, on the crazy downhills I do with bumpy tarmac having many 60-> 20mph maximum-braking turns, those have all failed with only the vulcanized patches holding up 100%.

Some good background info:
https://en.wikipedia.org/wiki/Vulcanization
https://www.freepatentsonline.com/4913950.html

HillRider

If you can, that would be helpful. I would really like to know the composition of these "vulcanizing fluids", specifically what the cross-linker and activator really are, if indeed they are present. As mentioned by one poster above, normally true vulcanization requires a crosslinker (usually a sulfur compound) and heat (a lot of it) to cause the crosslinking reaction that truly bonds a patch to the base rubber. How do these bike tube patch cements accomplish the same reaction at room temperature.

byte_speed

I must be doing something very wrong, every single one of the dozen or so I've tried has failed somewhere between the first day and two weeks.

I don't even trust them just to get me home anymore.

DannoXYZ 

Quick glance through ingredients shows:

Elmer's No-Wrinkle Rubber Cement
>70% Heptane
20-25% natural latex rubber
1-5% Isopropol alcohol

Rema Vulcanizing Fluid
60-95% Naphtha, petroleum, hydrotreated light
1-2.5% N-Ethylcyclohexylamine
other brands also contains: acetone, heptane, trichlorethylene, zinc-dibutyl dithiocarbamate/dibutylamine

Now we can see that the office-stationary "rubber cement" is clearly of different composition than "vulcanizing fluid" regardless of how it's labeled. Leave a bottle of rubber-cement open and you end up with a ball of rubber about 25% the size of the container. Leave a bottle of vulcanizing fluid open and it evaporates to nothing; very different stuff. The N-Ethylcyclohexylamine is a vulcanizing accelerator/catalyst which speeds up vulcanizing enough to occur at room-temperature (heat does the same thing). Ever see "RTV" on various rubber-sealants like caulk? The red uncured rubber on the patches provides the sulfur and in the old days with skinwall tyres, you can see a brown circle appearing on your tyre if you install the patched tube right away. This is caused by the release of various gases during the curing process.

A lot has changed in the past 20-30 years. Just because there was only one way to vulcanize rubber 30-years ago, doesn't mean that technology hasn't improved. Look at how materials technology has improved in frame materials, and how mechanical engineering designs created index shifting. Auto and computer technology has improved significantly in the past 30-years.

In the end, it's not an all-or-nothing, black & white, yes/no issue on patches. It comes down to a shades-of-grey on how well various compounds holds a patch to a tube. I'll do a demo video of "rubber cement" versus "vulcanizing fluid" after 24-hrs curing and show how easy or difficult it is to pull off a patch using both these products.

unterhausen

I have never tried rubber cement on tires, but it looks and acts so similar I probably will now when I patch at home. On the road I probably will still use the high price lbs stuff. I had an old kit from a shop I used to go to that wasn't REMA, I'm pretty sure the cement in that kit was rubber cement.

pdlamb

You're making a mountain out of the molehill which is different volatile solvents. If you patch a tube correctly, almost all the solvent will have evaporated when you apply the patch. The "natural latex rubber" in the Elmer's will persist, as will whatever fraction of the other cement isn't listed above.

FWIW, I used Rema until most of the trichlor evaporated, so I tried Elmer's. It's working for me so far, but I try to avoid single-downhill-run brake riding that erodes a pad away. Road riding, Koolstop pads that last for years, 90 +/- psi, and no failures in the last year and a half.

Paramount1973 

Not to muddy the water, although the presence of a cycloamine would suggest that the chemical was there as a vulcanization initiator, n-ethylcyclohexylamine is typically not specifically mentioned as such, but is usually cited as a herbicide intermediate.

I agree that the compositions of the vulcanizing fluid and the rubber cement are different in that one lacks the rubber latex. This suggests different modes of action. As you have stated, the question still remains - what is the efficacy of the vulcanizing fluid versus a high quality rubber cement? How effective is the vulcanization initiator in the absence of high pressure and heat? Are they actually roughly equivalent? As you suggest, the only way to settle the matter would be a side-by-side comparison. Really, to eliminate bias you would want to conduct it as a replicated, double-blind sort of study.

Metaluna

I have some that I bought from Wal-Mart. Seems to work as well as any other I've tried. It does say "rubber cement" on the tube, so I don't know if it's real vulcanizing fluid or not. I'll have to try spreading some on a piece of metal and see if it leaves a residue.

DannoXYZ 

The mechanisms are completely different, vulcanization cross-linking versus interdigitation. Smear some vulcanizing fluid on a glass mirror and compare to a smear of rubber-cement and the difference after a couple minutes is dramatic.

Preparing test samples now, however, it may not be possible to do complete double-blind as the appearance of the stuff is different and how they behave when applied. Although with video, we can scrutinize for any differences in procedure. Not to mention we have thousands of people who can repeat this experiment as well. In all cases, optimum preparation is key and I suspect a lot of the differences and failures people have had with patching comes in well before the fluid or patch is even applied. Failure to remove mould-release and surface cleaning is probably the biggest contributor. A metal buffing-wheel like used for auto-tyre repair can ensure complete cleaning and consistent surface preparation.

noglider 

Same here. Sometimes different products can perform the same function.

PeaceByJesus

This is one of the most informative threads on this subject, and i had done a good amount of Googling before i began a thread "best tube patch cement for the money," and was informed about this one.

While it seems there still may be debate on his issue, i was asking what would be the best tube patch cement for the money if you would like to use pieces from old inner tubes as patches. Which depends upon whether there really is a difference.

I see (all prices include S+H),

1. Monkey Grip 32 fl oz Rubber / Tire Universal Cement for US $20.00

2. Slime 1050 Slime 1050 Rubber Cement - 8 oz. for 12.00

3. Camel Tire 12086 Universal Cement 8 oz. for 16.65

4. Rema Tip Top SPECIAL CEMENT BL No. BL-8 8 oz for 21.00

5. Monkey Grip
EZ Fix Bicycle Patch Kit, 10 for 12.00 (w/ S+H)
Quantity: 5 patches

(I also see "SUNLITE" Patch Cement 1.00 per 1.oz tube, but you have to buy $15.00 worth.)

I have put over 15 patches on more than one 20" tube, with roofing rubber inside the tire, as that is cheaper than a new tube.

drbenjamin

I'm looking forward to this thread too, and I'd like to offer up that while I agree that DannoXYZ has pointed out compositional differences between rubber cement and vulcanizing fluid, neither naptha nor cyclohexylamine is a cross linker. Cyclohexylamine can be an accelerator but requires a thiol to do the actual crosslinking. So there must be other ingredients in the vulcanizing fluid.
Also, despite suspecting that the 2 liquids are not the same, I've been using rubber cement to glue patches on my commuter tire for a couple of years (the darn little tubes of vulcanizing fluid kept drying up!) and so far I've had no troubles with patches coming off. Still, if there's proof that covalent chemistry can occur with the appropriate reagent then I will switch back, just on principle!

PeaceByJesus

Note also that both

Special Cement BL (Non Flammable)

The key to REMA TIP TOP's exclusive Blue Bonding System, Special Cement BL creates a nearly indestructible bond between tire and repair unit. Specifically designed for the application of REMA TIP TOP Radial, Bias-Ply and Universal, Minicombi & RemaStem repair units. Use for chemical installation of REMA TIP TOP blue bonding layer repair units, Blue Floater Gum and chemical vulcanizing compounds.

And,

Special Blue Cement (Flammable)

The key to REMA TIP TOP's exclusive Blue Bonding System, Special Blue Cement (flammable) creates a nearly indestructible bond between tire and repair unit. REMA TIP TOP's newest Special Blue Cement (flammable) is free of CFC and aromatic compounds. Specifically designed for the application of REMA TIP TOP Radial, Bias-Ply and Universal, Minicombi & RemaStem repair units. Use for chemical installation of REMA TIP TOP blue bonding layer repair units, Blue Floater Gum and chemical vulcanizing compounds.

claim the same thing, but the latter is more expensive.

Tunnelrat81

Sunlite Bulk Patches on amazon.

100 patches for < $7

These are VERY nice patches. A bit larger than you typically get in the small LBS patch kits...and not bulky. They are thin and patch beautifully. Win-win. Cheap and superior. I'm half way through a box of these that I bought a few years ago. I patch everything with full confidence and have tubes with 3,4,5 patches on them that I trust every bit as much as new.

https://www.amazon.com/SunLite-93007M...7953134&sr=8-1

-Jeremy

Shimagnolo

In my experience, they are good to get you home, but don't last.
So when I get home, I immediately remove them and replace with a permanent patch.

Also, I learned the hard way not to use them in cold weather.
I used one last winter which started leaking just a mile down the road.

PeaceByJesus

We should include S+H for price comparisons, and Amazon price is approx 10.00 for 100 patches. As said, the (Hong Kong) ones i was buying from Ebay were 1.56 for 48 patches, which are now 1.88 but the Sunlite are likely better.

Metaluna

Those blue cans look like they're not the right stuff, and the description seems to say that they are meant for different types of patches. I've always seen the green cans being sold for bicycle applications with the orange and black patches.

DOS

Here is Rema 8 oz for 15.93: https://www.outsideoutfitters.com/p-3...FUdN4AodlVugXw Shipping is a bit stiff at almost 9 bucks, however.

PeaceByJesus

Which is why there are threads like this. But you are right, as i actually called up REMA, and spoke with a gentlemen who gave a good explanation as to the science behind all this, and to be short, the blue cement (he said they teach their salespersons to call it cement, not glue, due to the stronger connotation of the former) is designed for tire patches, and which have a cushion, while the Cold Vulcanizing Fluid is for use with their patches, which are specially manufactured for bonding with their cement.

I explained my desire to find a cement that would work best for neighborhood bikes using cheap Chinese patches and he recommended the Cold Vulcanizing Fluid, the cheapest i found for 8oz w/ S+H being 18.00

If i think Slime would do the same for 12.00 i may get that, though about 10 of the Monkey Grip kits @ 0.69 a kit (5 patches with cement) plus 5.00 S+H is attractive, as you would get less cement, but have a fresh tube regularly. Thank God for choices!

dscheidt

You should dig up and read Rema's patents (US Pat. no. 2,638,955, if my memory works is an interesting one), then. Like I said in my first post, it's a system. Three parts: tube, patch, fluid. The tube facing part of the patch is unvulcanized rubber, with an ultra accelerator in it. There are a number that are suitable, but zinc thiocarbamates are usual. Cyclohexamine in the fluid activates the zinc thiocarbamate, and you get cross linking. there are different chemistries in use, but the general idea is the same: patch contains an ultra-accelerator and sulfur source, glue contains an activator. (I had a long discussion about this with a chemical engineer who designed patch systems for all sorts of things, ranging from rubber boots to boats to military equipment. There are some very exotic chemistry in the specialized products.)

dscheidt

If you live in the US, an auto parts store is likely to have a can of suitable cement for which you would not have to pay shipping and handling.

PeaceByJesus

Right (people are presently more difficult!), and these are manufactured for more critical applications than bikes used for neighborhood riding, in which cheap patches usually work, and most flats are a result of bald tires (despite advising them not to skid!). The 8oz can of Slime for 12.00 total would be the best buy it seems, for that amount, but my prayerful purchase was a lot of the Monkey grip kits, at about 1.10 a piece including shipping (Blain's Farm & Fleet)
Thanks and God bless for all the help and info. Hope it will be a help to others in the future as well.

DannoXYZ 

Yes, this is right. The system of patch+fluid is very specific. Rema patches doesn't work well with the Camel fluid and Camel patches don't work well with Rema fluid. It's like 2-part epoxy.

I've had moderate success with using old cut-up tubes as patches. But they require so much work to completely buff clean and cut up. They also don't provide the other half of the chemistry needed for full strength bonds.

HillRider

OK, finally a reasonable chemistry based explanation of what is being sold as "vulcanizing fluid" and how it really does cross link the bond between the tube and the patch. Thanks for the reference and it's nice to know it's not all marketing puffery and snake oil.

That said, plain, cheap Elmers Rubber Cement used with REMA patches has worked for me with complete success for patching tubes for many years. It may not be the best system from a chemistry or theoretical standpoint but it does work. Now, I don't routinely bomb down Alpine passes and heat my rims red hot but for the normal hilly conditions around me the patched tubes have been 100% reliable.