Wintergreen oil for revitalising rubber parts

[hampshirehog]

I bumped in to an article on the interweb about using wintergreen oil for softening old hardened rubber parts. Unfortunately, follow up searches seem to offer all sorts of conflicting advice as to how to use it and the longer term effects on the rubber. Could be the panacea for all things rubber or could ruin the difficult to replace part.

Has anyone on here used it? If so how did you use it and what were the results?

 

[Adler]

I bumped in to an article on the interweb about using wintergreen oil for softening old hardened rubber parts. Unfortunately, follow up searches seem to offer all sorts of conflicting advice as to how to use it and the longer term effects on the rubber. Could be the panacea for all things rubber or could ruin the difficult to replace part.

As anyone on here used it? If so how did you use it and what were the results?

I found this thread to be interesting;

http://forums.sohc4.net/index.php?topic=49393.0

cellulose thinners apparently works... Also someone makes their own carb boots on page 2!

 

[waterman]

I found this thread to be interesting;

http://forums.sohc4.net/index.php?topic=49393.0

cellulose thinners apparently works... Also someone makes their own carb boots on page 2!

The last poster of above link had used xylene alone with good results. I am not sure what is in wintergreen oil that would specifically soften hardened rubber, except maybe the lubricity of the oil. I can understand xylene since it is a fairly decent organic solvent. If used, please exercise caution, this should be used out doors and is extremely flammable. I wonder how long the rubber remains flexible.

 

[BlackStar]

We used to use wintergreen oil on foam rubber slot car and RC car tires to soften them up for better grip. During the off season they would usually crack and need replaced, so beware of potential short term benefits.

 

[Guest]

One of the jobs I've had is rubber chemist. Many rubber compounds have oil in them, such as tire treads and sidewalls. Carb boots are probably made from nitriles, because nitriles resist oil and gasoline. Oil and such things is not usually added. Some waxes were probably added as plasticizers, which both make the rubber softer in service, and make it easier to mold the parts.

Rubber slowly oxidizes in service. Some anti-oxidants and anti-ozonants are often used, but those compounds are used up as they work. The rubber hardens as it oxidizes.

Solvents like xylene are absorbed by many types of rubber, making them "swell". Swelling destroys the mechanical strength. As solvents evaporate, some or most of the mechanical strength returns. And, as solvents evaporate, they can carry out oils and plasticizers that were compounded into the rubber when the part was manufactured.

I've never heard of this technique before. The idea of using xylene to carry a thin oil into the rubber, and letting the oil evaporate, makes sense to me. If rubber parts are hard and will have to be thrown out anyway, it seems to me that there is little to lose.

I would start with the technique in the link, using about 30% wintergreen oil for 12 hours. I would not touch the parts with my hands until the xylene had evaporated, which shouldn't take very long. And I would check the condition of the boots monthly for a while, to be sure that they hold up.

I would not use this for any parts in the brake system or forks. Too dangerous.

 

[Dogma]

Interesting. Any guess how long the benefits might last?

 

[solo 2]

I am a member of the SOHC forum also and was skeptical of the outcome of this method, but seeing as I could stand on my intake rubbers with no effect I had nothing to lose as I was going to buy new ones. I had a 1/2 gallon of xylene hanging around so I went down to the local Walmart pharmacy and bought 2-4oz bottles of wintergeen oil ($15) and dumped them in. Well 24 hours later I had brand new pliable rubbers, you can squeeze them together with 2 fingers. Other members who have tried this say they are still pliable 2 years later and I have no reason not to believe them.

I tried the thinner intake horns on the CB and they came out swelled to about twice their normal size, but just as everyone said 2 days later they were normal size and soft as new.

Apparently this method also works if you dump the oil into water then bring it to a boil and drop your rubbers in for about 1/2 hour or so. Someone may want to try this if they don't have xylene or just don't want to use something that toxic.

During the discussions on the forum there was some speculation that xylene alone would work..NOT, tried it for 2 days before buying the oil and were still hard as rock.

So there you have it, a genuine testimonial from someone who has tried this with great results. Just thought I'd let my brothers on the GS forum in on this.

 

[wdavie]

Hi guys I want to do this trick with my airbox rubbers. There is a local paint supplier who supply thinners at a pretty reasonable rate, not sure iof it contains xylene though. Would any paint thinners work? Cheers Wayne

 

[Guest]

Most would, but not any. The solvent has to be one that the rubber absorbs. To figure that out requires knowing what kind of synthetic rubber the boots are made of and its characteristic in each type of solvemt. Suzuki won't tell us who made the boots 30 years ago, or the rubber recipe. Digging out the characteristics in solvent would take several hours.

My suggestion: ask around to see if xylene is available. (Might not be in the UK.) if not, find a can just big enough to hold a boot, and buy the smalled amount of another solvent. Put the boot in the can and a tiny bit of solvent, enough to cover the bottom centimeter or so. Watch to see if it starts to swell over several hours. If it does, try the wintergreen oil/solvent mixture for the entire boot. If not, try a different solvent.

 

[jsandidge]

going to try

going to try

I replaced my intake boots with new, but thought the airbox boots looked fine. Now that everything is going back together, the airbox boots are giving me fits. They keep slipping off when I tighten the clamps. The diameter of the opening is correct only at the very opening on 2 of them. The opening then gets smaller and won't slide onto the carb all the way. It appears they have shrunk some.

The other 2 keep the same diameter throughout the entire section that slips onto the carbs. These 2 clamp down fine. All 4 feel a little harder than they should. I know they are all the same, as they have the Suzuki part number molded into the rubber. I have new clamps from the PO.

I read on the SOHC forums about using the Wintergreen oil and nearly boiling water. I have a hot-plate in the garage, so I don't run the wife out of the house. I hear this stuff is quite "fragrant". This only cost me a little over 7 bucks at Walgreens, so I'm not out much if it doesn't work.

I'll give it a whirl, and post the results. Worst case, I buy new boots. Even Z1 carries them now. Mike at Z1 was the guy who gave me this tip to begin with, although he said he hasn't tried it.

 

[GelandeStrasse]

I tried "Oil of winter green", for more info see Methyl salicylate here http://en.wikipedia.org/wiki/Methyl_salicylate You can get in the drug store (maybe chemist for Brits).
Pan of hot water or better, a slow cooker, add winter green oil then put in your hardened rubber parts and leave for around an hour.
It'll soften them and give them another lease of life. It won't make them like new but you'll get a bit more use outta them.
You have to be careful how long they're in the mix, too long and the rubber just goes super soft and starts expanding out of the original shape.
I'd use it again in an emergency but not as a proper fix.
One bonus is your shed will smell of menthol for ever after for goodness sakes don't use a pan from the kitchen for the same reason! Oops!

 

[jsandidge]

It's a go!

It's a go!

Well, I gotta admit I was skeptical, but this gets a thumbs up! For good measure, right after removing from the hot water and wintergreen oil, I slid the boots onto my spare set of carbs and lightly clamped them. I left them this way for a couple of hours to help the rubber re-set in the proper shape. Even after they were completely cooled, the rubber was still soft. I popped them back into the airbox, and fairly easily slid them onto the bike. They stayed in place, even when I tightened the clamps. Before, they would slide right off. I don't expect this to be a permanent fix, but it lets me focus on some of the many other things on this bike that need attention.

 

[chuck hahn]

Honda forum guys say to put the parts in a zip lock baggie and use Glyserine. set overnight. They say its as soft as new the next morning.

 

[jsandidge]

running smooth

running smooth

With the newly softened boots, I have finally been able to do a proper vacuum synch. She is running smooth now. Sprayed some starter fluid around the boots to test for leaks, and none found. Happy camper now!

 

[Guest]

Let's make this a "sticky" then.

 

[jwhelan65]

Honda forum guys say to put the parts in a zip lock baggie and use Glyserine. set overnight. They say its as soft as new the next morning.

Wonder how it would work on carb boots? exacerbating deterioration would be my concern.

 

[Guest]

Wonder how it would work on carb boots? exacerbating deterioration would be my concern.

Rubber hardens through oxidation, cross-linking and evaporation.

Oxidation occurs slowly, as atmospheric oxygen, O2 and ozone, chemically combine with the rubber polymer molecules. O2 works slowly, while ozone works faster. Rubber parts are made with anti-ozonants and anti-oxidants to retard the process. After 30 years, those protective chemicals are mostly gone.

Cross-linking could also be called vulcanization. Rubber is like thick gum before it is vulcanized. (Chewing gum is litteraly rubber.) Vulcanizations stops the rubber molecules from sliding against each other. Think of just cooked spaghetti as rubber before vulcanization. The long strands are only tied at a few places when the rubber item is made. More cross-links can be made after the part is in use. Ozone is a primary culprit.

Evaporation: Most rubber items have some oil in them to keep them soft. Car tires are about 1/3 oil. Volatile components in oil can evaporate. More importantly, oil dissolves in gasoline. Gasoline vapors penetrate the carburetor boot, and can bring oil to the surface, allowing it to rub off or evaporate. The process is slow, but after 30 years, it adds up.

Soaking the parts in oil lets some of the oil be replenished. The trick is using an oil that doesn't do bad things to the rubber. Too much oil, too long, the wrong oil, all would destroy a boot.

It seems that some home experiments have discovered that wintergreen oils does well on GS carb boots. There is really nothing to loose by trying it. The worst that can happen is that buying new boots would be necessary, and the owner would be out a few dollars more.

(I used to work with rubber chemistry.)

 

[jwhelan65]

Rubber hardens through oxidation, cross-linking and evaporation.

Oxidation occurs slowly, as atmospheric oxygen, O2 and ozone, chemically combine with the rubber polymer molecules. O2 works slowly, while ozone works faster. Rubber parts are made with anti-ozonants and anti-oxidants to retard the process. After 30 years, those protective chemicals are mostly gone.

Cross-linking could also be called vulcanization. Rubber is like thick gum before it is vulcanized. (Chewing gum is litteraly rubber.) Vulcanizations stops the rubber molecules from sliding against each other. Think of just cooked spaghetti as rubber before vulcanization. The long strands are only tied at a few places when the rubber item is made. More cross-links can be made after the part is in use. Ozone is a primary culprit.

Evaporation: Most rubber items have some oil in them to keep them soft. Car tires are about 1/3 oil. Volatile components in oil can evaporate. More importantly, oil dissolves in gasoline. Gasoline vapors penetrate the carburetor boot, and can bring oil to the surface, allowing it to rub off or evaporate. The process is slow, but after 30 years, it adds up.

Soaking the parts in oil lets some of the oil be replenished. The trick is using an oil that doesn't do bad things to the rubber. Too much oil, too long, the wrong oil, all would destroy a boot.

It seems that some home experiments have discovered that wintergreen oils does well on GS carb boots. There is really nothing to loose by trying it. The worst that can happen is that buying new boots would be necessary, and the owner would be out a few dollars more.

(I used to work with rubber chemistry.)

Good info, thanks

 

[chuck hahn]

Cant comment on Glycerines effects or effectiveness Joe..never have used it. Just relaying what a group on the Honda SOHC forums were saying about its use.

 

[ezmack]

I have an old set of airbox boots I decided to soak in marvel mystery oil just to see what happened. The effect, if it even had one was negligable after 24 hours. They've been in there for probably 2 months now, I just picked em up and flexed them a little when I saw this thread. Still pretty darn stiff. I wouldn't count on any drastic changes from it. My $.02 atleast. Sure does smell nice though.