vulcanizing compound and tire plugs

[_brian_]

I have a question of controversy.... I want to discuss tire plugs. Not should you should you not, but some detail. In the kits, you find those that state the plugs are self vulcanizing, some include rubber cement, some include a vulcanizing compound, and there may be even others with methods I do not know. My question is on the vulcanization portion.

1. What is the difference between a vulcanization compound and rubber cement? I read a variety of opinions, and it appears they are at very least similar, but I wonder if someone could share the actual technical details behind them.
2. Regarding the plugs themselves, I read that some state the ones that are self vulcanizing contain the vulcanizing chemical(s) so you either need nothing additional, or you can just use rubber cement. I understand that vulcanizing requires heat, so this clearly refers only to chemical vulcanizing, as the same in #1. Some also claim that using a vulcanizing compound with a self vulcanizing plug does more harm than good.

I in no way intend to encourage or promote the use of plugs. I am only interested in the chemistry / science portion of the plug process itself. I have personally used plugs for over 20 years and I have never had any issues, plugging only within the crown area though. I am already knocking on wood waiting for the one time that it fails and kills me. I have never used a plug "dry", but I have used both rubber cement and vulcanizing compound and cannot say I really noticed anything different. But I do wonder what I am not able to see, aside from the obvious lack of inspection of the inside of the tire. Again, that is not related to my query here.

 

[u2slow]

I recently had a tire plug fail. Actually, it took me some time to notice. It simply started a slow leak that would stabilize at ~20psi. No big deal. Time to change the 18yo tires anyway.

 

[zendriver]

The way I understand it, self vulcanizing plugs somehow has the chemical that is released, when the plug is removed from packaging and inserted.

Not my first choice for tire repair and have not use it a lot, but the one's I did do, held as long as I ran the tire.

If one did "fail", not sure how It could kill any one, unless the tire was on an Indy car. It would probably just leak.

Maybe we should ask the expert.

 

[Old Man Roger]

I've never used glue or anything. I've always used the reamer to heat the hole by just sawing away at it right before I put the plug in.

 

[ChevyEFI]

I have a Victor reamer and inserter.
Always did plugs dry. No failures after dozens of them.

My older son was asking me what they're made of today. Guess I should have told him they were self-vulcanizing.

 

[_brian_]

I know there is a huge debate between those who are for and against use of plugs. My personal feeling on the topic is before you debate its use, you need to understand what it is, what it does and how it works.

 

[joecon]

If you are using a plug, [or a patch the chemistry is the same] that vulcanizes
to the tire you should use the chemical that comes with the product. I like to use
Tech products, so when I use a tech plug I use the chemical that is specified by Tech
for that product. The chemical vulcanizing fluid is chemically designed to dissolve the
rubber and flow the two together so they become one. Rubber cement fills the void
and bonds to both the plug and tire but all three things remain separate. Most plugs
just fill the hole and can be pulled out, a good plug becomes part of the tire and can
not be removed.

 

[zendriver]

I know there is a huge debate between those who are for and against use of plugs. My personal feeling on the topic is before you debate its use, you need to understand what it is, what it does and how it works.

Using a piece of rubberized cord, to plug a hole in the tread area of a tire.

What are we missing?

 

[icthruu74]

Interesting discussion. I’ve plugged numerous tires over the years and have only had one failure. Years later it started to leak, so I pulled it and put in a new plug. I’ve never used any additional fluids or cements with them, but I do need some new plugs so I’ll have to research now.

 

[getbent4x4]

not sure on the question everyone says to just use a safety seal kit. Only tires Ive really had to plug were passenger or load range C rated. Seems like the D and load range E rarely puncture when being careful. I did have to do one load range E that got a L shaped screw in it.

 

[SeisMec]

What is the difference between a vulcanization compound and rubber cement?

In the early 1960's my dad repaired a bunch of scrapped out inner tubes for us kids to use swimming at my uncles lakeside cabin. He took us to at least three places before he found the type patch kit he wanted. After brushing on the compound, he lit it on fire then blew it out. He wanted that kit, because the ones with "just glue" were "no good".

I doubt their is any difference now days - just different names, but I'm with joecon - used what's in the kit.

 

[sberry]

Safety Seal doesn't really use glue but lube to allow the insertion. They do kind of stick to the inside of the casing. It looks like a gob of bubble gum that covers the hole, air keeps trying to force it back out so to speak. They work very well, are dot approved. Very well proven.

 

[trackwelder]

I like the Tech Tire branded plugs. I have a kit in three vehicles and a few in the garage. None of them have the original glue in them. I buy the smallest cans of tire glue from Napa and it works just fine.

 

[SGKent]

stick some stones between your toes and walk. That is what a plug does to a radial tire. Best patch on a highway radial is to put the tire on a tire machine, open it up, and install a vulcanizing patch on the inside. Some places who retread (I won't use one because of problems I had with them in my youth) won't retread a tire with a plug but they will with a patch. Say whatever you want but that is the way the cow eats the cabbage.

 

[Fedwrench]

https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=77

https://www.ustires.org/tire-repair-basics

 

[_brian_]

Using a piece of rubberized cord, to plug a hole in the tread area of a tire.

What are we missing?

The reply by joecon is an example of what is missing. Some kits have no glue, some include rubber cement tube and others have a vulcanizing compound ... and others even include no glue, but a container of a lubricant. Knowing what makes them different I believe is a good thing to know.

 

[_brian_]

Some very interesting points made. The reasoning behind my interest is I have used plugs over the years and never really had any issues, aside from sometimes finding the leak. I only do on my own vehicles and sometimes family, I want nothing to do with the liabilities involved in such things. I am very much aware of the shortcomings of a plug, and would love to have a tire machine [Hint to anyone that has a spare they want to send], but that is a bit out of my reach.

So I needed to order some new plugs as well as more vulcanizing compound. Reading what is all available, I started to wonder my query ... do I need the vulcanizing compound, is it really different than rubber cement, is the plug really self vulcanizing, etc.

 

[zendriver]

The reply by joecon is an example of what is missing. Some kits have no glue, some include rubber cement tube and others have a vulcanizing compound ... and others even include no glue, but a container of a lubricant. Knowing what makes them different I believe is a good thing to know.

Ok.

I guess I never purchased a tire plug kit, that did not have everything included.

 

[DFB]

We just started using the mushroom plugs now at the shop

No xtra glue, instruction do say not to the touch the tips with your fingers

Tool works great

https://www.stopngo.com/standard-model-tire-plugger/

 

[tym]

I've used some parts store brand tire plugs before. No cement, just a sticky black cord that is used "dry."

 

[Aqua-Andy]

I've used Safety Seal and Tech plugs for over 25 years and installed hundreds of them in customers tires as well as my own. Never had one problem or complaint. All I hear is stories about tire plugs failing and causing terrible accidents and insurance liability, but never any hard evidence that it ever happened. I have seen some of the cheap black tar coated rope style plugs leak but never anything catastrophic.

 

[theoldwizard1]

True "vulcanization" can only be performed once. It cause "elastomers" to "cure"/"harden". The process was invent by Charles Goodyear (yes, that Goodyear) and was used to cure natural rubber.

The process changes the molecular structure of the material. Once it is changed, there is no way to back. The process is different for different materials; vulcanizing natural rubber is different that synthetic rubber (neoprene, hypalon, etc) which is different from room temperature vulcanizing (RTV) silicons.


In the context of this discussion, I am sure that "self vulcanizing" compounds are pretty much the same as "rubber cement" designed for the same purpose.

 

[sberry]

I've used Safety Seal and Tech plugs for over 25 years and installed hundreds of them in customers tires as well as my own. Never had one problem or complaint. All I hear is stories about tire plugs failing and causing terrible accidents and insurance liability, but never any hard evidence that it ever happened. I have seen some of the cheap black tar coated rope style plugs leak but never anything catastrophic.

This is worth repeating.

 

[bwringer]

Those old vulcanizing fire patches for tubes were fan-freaking-tastic, but have been off the market for many years. I'm sure they were horrifyingly toxic or something, but I have no idea exactly what I might have been breathing in when I was a kid.

True vulcanization requires heat, so I'm in the camp that "vulcanizing compound" is rubber cement with a thick layer of marketing **** applied to the package. I could be wrong, of course, but I've never seen any such glop that looks, smells, or behaves the slightest bit differently than rubber cement.


Also, if you're looking for tire plugs for tubeless tires that you can apply externally, most brands work work just fine. But if you really want the next level, Nealey plugs are the finest on the planet, hands down:
https://www.nealeytirerepairkit.com/

They're sticky strings, but they're installed a little differently, and they're thinner. Long story short, no added glue is needed, and you end up with four thicknesses of the cord in the hole instead of two and a knot on the inside that makes it impossible for the plug to pull out.

 

[Jbullfrog]

I use a mushroom plug gun. One is from the 60ies, and the other is new. They are identical. I have new old stock boxes of plugs from the 60ies that are still moist, but I only use new plugs from Napa. They have an orange coating around the stem. The only problems I have encountered where they don't seal are nail holes at an angle or large punctures. We used to have 12 hayracks and did a lot of tire repairs during hay season. The sticky cord plugs worked most of the time. I have been around a lot of shops and have never heard first hand of a plug failure that was catastrophic.

 

[_brian_]

True "vulcanization" can only be performed once. It cause "elastomers" to "cure"/"harden". The process was invent by Charles Goodyear (yes, that Goodyear) and was used to cure natural rubber.

The process changes the molecular structure of the material. Once it is changed, there is no way to back. The process is different for different materials; vulcanizing natural rubber is different that synthetic rubber (neoprene, hypalon, etc) which is different from room temperature vulcanizing (RTV) silicons.


In the context of this discussion, I am sure that "self vulcanizing" compounds are pretty much the same as "rubber cement" designed for the same purpose.

This specifically is part of my question. Does anyone have "proof" of this? The statement here makes sense, that a true vulcanization can be done only once, and I do read that the vulcanization compound is is a chemical vulcanization. While there is a distinction there, I do wonder if it is simply a distinction of words vs a real difference. I mean, I can use a solution of soap and water, or I can brand it "the Leak Detector", but the name does not change the fact that the bottle still contains soap and water.

 

[zendriver]

Maybe "vulcanization" is used regarding tire plugs, because it sounds much better than "glue".

A tire plug does not become part of the tire, it's merely glued in place.

 

[welder4956]

It's been awhile, but I recall from my polymers class in college that vulcanizing is the use of heat and sulfur to promote crosslinking in the molecular chains in rubber. Crosslinking promotes elasticity and resists plastic deformation (slipping between the chains in the molecular structure). In tire plugging, I would expect that a sulfur-containing compound is used in the "glue" to promote crosslinking (bonding) between the tire and the plug. Lighting the "glue" on fire provides the necessary heat. So, a "vulcanizing" tire patch or plug should have some form of sulfur and heat involved in the process.

 

[_brian_]

It's been awhile, but I recall from my polymers class in college that vulcanizing is the use of heat and sulfur to promote crosslinking in the molecular chains in rubber. Crosslinking promotes elasticity and resists plastic deformation (slipping between the chains in the molecular structure). In tire plugging, I would expect that a sulfur-containing compound is used in the "glue" to promote crosslinking (bonding) between the tire and the plug. Lighting the "glue" on fire provides the necessary heat. So, a "vulcanizing" tire patch or plug should have some form of sulfur and heat involved in the process.

Interesting. This explains why some people light the "glue" on fire.

 

[SeisMec]

Those old vulcanizing fire patches for tubes were fan-freaking-tastic, but have been off the market for many years.

Thanks. I feel dense for not having remember what they were called.

I think fire patch kits had pretty well disappeared by the '70s. Back then, instructions for the non-fired kits (almost?) always warned against lighting the GLUE on fire.

I'd guess that any glues in modern kits have an exothermic reaction with the patch and/or tire rubber.

 

[sberry]

They lit them on fire cause they were in a hurry and didn't want to let it sit till it was ready.

 

[rlitman]

stick some stones between your toes and walk. That is what a plug does to a radial tire. Best patch on a highway radial is to put the tire on a tire machine, open it up, and install a vulcanizing patch on the inside. Some places who retread (I won't use one because of problems I had with them in my youth) won't retread a tire with a plug but they will with a patch. Say whatever you want but that is the way the cow eats the cabbage.

This is dangerously wrong. The inner patch will keep air from escaping, but will allow water to get into belts, eventually allowing the belts to rust, which can end up causing catastrophic results.

The tire industry agrees that plug patches are the only approved repair method that does not reduce your speed rating. You MUST have something plugging both the inside and outsides of the hole to protect the steel belts, as they're the most critical component of the tire.

...True vulcanization requires heat...

No. It does not. Hence, RTV exists.

Maybe "vulcanization" is used regarding tire plugs, because it sounds much better than "glue".

A tire plug does not become part of the tire, it's merely glued in place.

I think you missed the point of what glue actually is. It is a bonding at the molecular level. So yes, it IS a part of the tire, regardless of whether or not you can still define a boundary between tire and plug after installation.

It's been awhile, but I recall from my polymers class in college that vulcanizing is the use of heat and sulfur to promote crosslinking in the molecular chains in rubber. Crosslinking promotes elasticity and resists plastic deformation (slipping between the chains in the molecular structure). In tire plugging, I would expect that a sulfur-containing compound is used in the "glue" to promote crosslinking (bonding) between the tire and the plug. Lighting the "glue" on fire provides the necessary heat. So, a "vulcanizing" tire patch or plug should have some form of sulfur and heat involved in the process.

You have a good memory. Vulcanization was a trade name for one of the earliest industrial processes that was able to create a stable cross-linked rubber material.

But all sorts of chemical reactions create cross-linking. RTV does this as it cures. Epoxy relies entirely on cross-linking for its strength. Some polymers can be cross-linked using catalysts and heat, some chemically. Even radiation can be used for cross-linking (as is used in some forms of heat shrink materials).

 

[SeisMec]

What wait time? Patched tires on a daily basis in a service station in the early '70s.

1. Hit the area to be patch area (inside the tire) with a pneumatic tire buffer.
2. Smeared glue on the buffed patch area.
3. Peal the plastic film off the face of the patch & slap it down.
4. Roll the patch down.
5. Done.

 

[sberry]

They sposed to flash off and dry like contact cement which is what it is. Changes from wet looking to dry, ideally 5 or 10 minutes depending. Today we use liquid buffer. It acts a little similar to pvc primer, cleans and softens the surface. Probably as good or better than the physical was or is?

 

[sberry]

Just have a repair on the bench now.

 

[sberry]

Ok, the update. My neighbor came in with this fix right as I had considered taking a pic for this thread. It was a new tube but he damaged it. I cut 1/3 a patch, 1/4 really and glued it over with a tailor patch. It was on the inside of the tube. New let me give it a squirt of that juice, glue wait 5 minutes roll the patch on and its about like a welded repair.
It worked fine evidently either way it was done, its pitiful downtime if a guy was busy.

 

[sberry]

If it was something a guy was driving and heat a factor he should have mounted it tubeless, the tube was a waste, doesn't matter, it should have had a new tire. It worked out.

 

[zendriver]

I think you missed the point of what glue actually is. It is a bonding at the molecular level. So yes, it IS a part of the tire, regardless of whether or not you can still define a boundary between tire and plug after installation.

I think you missed the point that by definition, a tire plug is not "vulcanizing".

If, like a tire patch, it's possible that a plug can work it way loose, why would it be considered "part of the tire"? It's glued in.

 

[sk farmer]

Those old vulcanizing fire patches for tubes were fan-freaking-tastic, but have been off the market for many years. I'm sure they were horrifyingly toxic or something, but I have no idea exactly what I might have been breathing in when I was a kid.

True vulcanization requires heat, so I'm in the camp that "vulcanizing compound" is rubber cement with a thick layer of marketing **** applied to the package. I could be wrong, of course, but I've never seen any such glop that looks, smells, or behaves the slightest bit differently than rubber cement.


Also, if you're looking for tire plugs for tubeless tires that you can apply externally, most brands work work just fine. But if you really want the next level, Nealey plugs are the finest on the planet, hands down:
https://www.nealeytirerepairkit.com/

They're sticky strings, but they're installed a little differently, and they're thinner. Long story short, no added glue is needed, and you end up with four thicknesses of the cord in the hole instead of two and a knot on the inside that makes it impossible for the plug to pull out.

^^^^^this^^^^^

if have probably used hundreds of these. i won't use anything else.

 

[engineer2]

It's been awhile, but I recall from my polymers class in college that vulcanizing is the use of heat and sulfur to promote crosslinking in the molecular chains in rubber.

That's what I remember. Two pieces of natural rubber were coated with powdered sulfur. Press together with heat and the sulfur will cross-link the rubber molecules.