Wintergreen oil for revitalising rubber parts

[Guest]

I want to add an update to the wintergreen oil use for the carb to airbox rubbers. I found in my garage today a large baggie that contained 4 smaller baggies each with one rubber boot that was soaked in the wintergreen oil/xyleen thinner concoction.

I had soaked them overnight and then placed each one in a quart sized sealable plastic bag. The date I put on the bags was 9/28/2015. Now 2+ years out, the rubbers are as hard as a frozen hockey puck.

That surprised me as they had been treated and then sealed in an airtight bag, but I guess it just shows that the re-newing is only a temporary thing and will likely need to be redone occasionally.

Hope this is a help to somebody.

Rubber, as used in hoses, gaskets, tires and so on, is not a material. It is a mixture of materials. The predominant material in those products is one or several polymers that are also called rubber. The rubber polymer provides a flexible molecular lattice to which other chemicals are added. That rubber mixture must be cured to provide dimensional stability needed in the rubber product. Typically, 1/3 to 2/3 of a rubber mixture are the added chemicals. Books can be written on how rubber mixtures deteriorate with age, heat, light and other chemicals.

My guess is that the boots are made from a relatively inexpensive type of rubber, without a lot of attention how the boots will age. GS motorcycles are now at least 30 years old. Those boots have been exposed to a lot of heat, hydrocarbon fumes, UV light and flexing. With enough time and money, a rubber specialist could design and mold 100-year boots. They would cost too much to make sense on a machine that will probably not be on the road more than 15 years.

 

[Dogma]

Rubber, as used in hoses, gaskets, tires and so on, is not a material. It is a mixture of materials. The predominant material in those products is one or several polymers that are also called rubber. The rubber polymer provides a flexible molecular lattice to which other chemicals are added. That rubber mixture must be cured to provide dimensional stability needed in the rubber product. Typically, 1/3 to 2/3 of a rubber mixture are the added chemicals. Books can be written on how rubber mixtures deteriorate with age, heat, light and other chemicals.

My guess is that the boots are made from a relatively inexpensive type of rubber, without a lot of attention how the boots will age. GS motorcycles are now at least 30 years old. Those boots have been exposed to a lot of heat, hydrocarbon fumes, UV light and flexing. With enough time and money, a rubber specialist could design and mold 100-year boots. They would cost too much to make sense on a machine that will probably not be on the road more than 15 years.

I'm not sure about that last sentence. For sure 100 year parts would not make sense, but a lot has been learned about rubber parts since the '80's. I've had OEM GS boots go bad in just a few years, but my '01 ZRX has a lot of rubber intake parts showing no sign of degradation. I think we should add add that GS rubber was designed with no anticipation of the fuel formulations they would eventually have to deal with. I don't really have any knowledge that points at ethanol, but why should that stop us blaming it? I sometimes toy with the idea of making molds for my GS intake parts and casting some replacements from modern fuel-rated silicone.

 

[roeme]

(...) I've had OEM GS boots go bad in just a few years, but my '01 ZRX has a lot of rubber intake parts showing no sign of degradation. I think we should add add that GS rubber was designed with no anticipation of the fuel formulations they would eventually have to deal with.(...)

Eh, I suspect that was just bad/insufficient QA back then, a bad batch that slipped under the radar, or the manufacturers simply didn't know yet what to measure.

 

[Guest]

Rapid degradation indicates either very harsh service conditions or a gross mistake in the ingredients.

In the 70s and 80s rubber products manufacturers definitely knew what to measure.

It would be more likely that someone made fakes and found a way to put them into the OEM distribution stream. I know that sounds far-out, but it happens all the time with drugs in the US. Buy Chinese crap and sell it at huge mark-ups.

 

[Dogma]

Maybe. More data: The 850 and 1000G airbox boots both shrank & hardened over the same winter. I rode the 850 to BC that May with the shrunken 1000G rubber. The 850's boots were about twice as old as the 1000. On one set, I noticed a sticky substance on the bottom of the boots when I removed them. So, I think something attacked them chemically. I don't remember if I was storing them with Sta-bil yet.

 

[Guest]

You'll never know for sure what the proximate cause is.

A possible problem is that Suzuki might be selling off its old stock, without new boots being manufactured.Rubber deteriorates as it ages. Good conditions can minimize degradation, but not eliminate it.

 

[Guest]

Its also worth remembering that some of the available NOS parts may have been sitting on a shelf in some closed dealership with the end result being not so good.
We completed two Suzuki two stroke cafe builds last year and are working on two more. For these projects, I?ve had some bad luck getting rather awful NOS parts.
This has been a problem for the hard-to-find Suzuki two stroke parts and probably will eventually become more of a problem for the GS bikes.

 

[Griffin]

Resurrecting a dead thread because useful information is at hand now.

Good YouTube video on rubber softening experiment using (among other things) wintergreen oil (Methyl Salicylate): https://www.youtube.com/watch?v=EnGsllKvheQ


Where to get it in industrial form for WAY cheaper than drugstore OTC medicinal form: https://www.amazon.com/Methyl-Salic...=1541783945&sr=8-5&keywords=Methyl+Salicylate

I have used the above-referenced product (mixed 3:1 with Isopropyl Alcohol) soaked for three days on several sets of carb boots and other rubber parts (side cover grommets, seat and gas tank bumpers, etc...) with excellent results.

My original 1 pint bottle is about empty now, and I have been able to treat a lot of parts with it quite economically.

 

[bwringer]

I just treated a set of GS intake boots with Rubber Renue with good results. The boots were in good shape, but I needed a little bit of softening so I could get the carbs off and on without extreme measures.

That said, Rubber Renue is the most expensive route; if you look at the MSDS, it's simply 25% Methyl Salicylate and 75% Xylene. You can buy cans of Xylene at any home improvement store for less than $20 a gallon, and Griffin posted a link to the methyl salicylate above. As he noted, you can also use isopropyl alcohol as a "carrier" for the methyl salicylate.

I wouldn't expect any such treatment to resurrect damaged rubber bits, but it can work great on things that are just old and a bit hardened and shrunken.

 

[Guest]

An occasional "prophylactic" treatment might extend life considerably. Rubber boots will not harden uniformly. Areas that are stretched, and/or exposed to flexing, sunlight and so on will start to harden first. The flexing will be concentrated in softer areas, so those areas will flex more than if the entire boot flexes. Concentration of stress will lead to micro-cracks, and the process will accelerate.

So, maybe an annual application of something like Rubber Renue would extend the life considerably, by interrupting the hardening at an early stage.

I wonder if it would help windshield wipers? We certainly shell out too much for them.

 

[Buffalo Bill]

I just treated a set of GS intake boots with Rubber Renue with good results. The boots were in good shape, but I needed a little bit of softening so I could get the carbs off and on without extreme measures.

That said, Rubber Renue is the most expensive route; if you look at the MSDS, it's simply 25% Methyl Salicylate and 75% Xylene. You can buy cans of Xylene at any home improvement store for less than $20 a gallon, and Griffin posted a link to the methyl salicylate above. As he noted, you can also use isopropyl alcohol as a "carrier" for the methyl salicylate.

I wouldn't expect any such treatment to resurrect damaged rubber bits, but it can work great on things that are just old and a bit hardened and shrunken.

I have not used wintergreen oil, but wondered if it works as well on human skin? Like to buy some for some close friends. :love_heart:

 

[red1100]

In all the auto and now motorcycle restorations I have done I?ve had great success with cleaning rubber and making look like new,wiring,small plastic and non painted parts, rubber grommets,body plugs,plastic and cast emblems and the like dipped in a clean 5 gallon bucket filled with a 50/50 mix of water and simple green. I let it sit for about a week and take the pieces out one at a time and thoroughly clean them. Let everything dry for a few days and they are ready to go.It?s amazing how clean and new looking it all is. Rubber is soft and pliable,wire harnesses have lots of connectors in plastic or steel all look new. It won?t take off wire markings or discolor anything. Naturally on intake boots and the like it won?t repair cracks but will clean them as new. I got the entire wire harness for a 70 Superbee wrapped in a coil to fit in a 5 gallon bucket. Give it a try.

 

[Guest]

Being a RC enthusiast, I did an experiment with Methanol RC fuel and was pleasantly surprised with the result. Go to your local hobby store and get a liter of fuel. Cover the hard rubber air intake boot with the fuel in a container and leave for at least 24 hours. Remove and clean. You have a "revitalized" rubber boot that is soft and pliable again.

RC fuel contains mostly synthetic oil such as Klotz 200 and sometimes a small percentage of Castor oil as well. The Methanol just acts a a carrier to get the oil absorbed into the rubber.

 

[Gorminrider]

wintergreen oil works somewhat but by itself or with alcohol evaporates out pretty quickly...I haven't mixed it with xylene but it's plain that it's intended to be a superior agent to carry the wintergreen further into the rubber matrix.

It is not good for your skin, or to inhale, and softening old windshield wipers won't restore the worn edges.

if the $ or trouble or chemistry experimentation is not wanted, Warming the old rubber will suit many people in most cases to ease putting the carbs back in.