Wintergreen oil for revitalising rubber parts

[Gorminrider]

Skin conditioner..Walmat has it in the band aid section...dont ask me why its there, but thats where i found it here.

aah, thanks! I'll look again, but this thread has shown me that around here anyways, the simple remedies have been replaced on the drug-store shelves by the Brand-names that dilute them, add a bit of scent,lots of advertising and a higher price. When I ask the pharmacist, I get looks as though I were making a bomb or distilling crystal meth.

[ART]

Glycerine is the base stock from which nitroglycerine is made, so...

[bwringer]

Glycerine is the base stock from which nitroglycerine is made, so...

... and don't look now, but the salt you sprinkled on your egg this morning is made up of explosive SODIUM and deadly CHLORINE!

[Gorminrider]

(shh, they're reading this...)

[ART]

... and don't look now, but the salt you sprinkled on your egg this morning is made up of explosive SODIUM and deadly CHLORINE!

Nah, using mineral salt mix. The NaCl isn't much good for yer blood pressure.

Getting back on topic though, I've had pretty decent results with glycerine when it comes to softening rubber. Have ordered a bottle of wintergreen oil now, will test and compare. Fun!

[Gorminrider]

well, I tried glycerine and am not impressed yet.

True, it's less than half the cost of the Wintergreen oil I got...

First glycerine experiment:COLD, paint it on, rub it in. No quick useful result that I can see except slippery. Slippery is good to fit onto a carb but that's not the point here.

Next, the boot went into a glass jar with just glycerine liberally applied (but not swimming in it). The jar then went into boiling water. The glycerine did not vapourise like the WO, but some droplets were condensed in the jar with the lid on loose... maybe just atmospheric water?
No particular strong smell-a plus, if you don't like "spearmint flavour"
This was a disappointing test. It was wonderfully soft and a bit greasy when still warm, but at my room temperature (60F!) it went back to being hard as a rock, as it was originally.
It was not as good as the wintergreen using the same no-water ,no-solvent process.
Or even as good as WO, painted onto a Cold boot.

The above method is a fail for me.
BUT,
Next, I added water to glycerine just covering the boot in the jar and heated the jar in a pot of water to open boil until the pan ran dry- a better result, when cooled to room temperature....

So, Out in the shop, I tried jamming them each onto a cold carb. The wintergreened one went on albeit with hard pushing, but the glycerined one was just too hard for this mortal, though less hard than it was in it's pristine and aged state....really rock-hard rubber. Sounded like a marble hitting the floor...anyways,
The wintergreened one is definitely softer to the feel, despite being cooked two weeks ago.
There is no swelling once cooled from my "double-boiler" method. The lack of swelling that others mentioned may point to a failure in my method.
Neither is yet as "permanently" soft as when the rubber is new, or as soft as when warmed with hot water or a heat-gun.
I have not tried the simpler open pot and water method. Water is a good solvent....
to refresh, SVSooke and jabcb have tried "Rubber Renue"

http://www.thegsresources.com/_forum/showpost.php?p=1944794&postcount=22

It has the advantage of being applicable in situ without a heat gun or kitchen laboratory so would be a good precaution to apply it before removing carbs off old bikes. Meanwhile, I so far think I will heat-gun 'em and use WO because that also gives some result in that instance where I don't expect to just buy new boots.
A bit of glycerine splashed around won't hurt either. Slippery stuff on rubber.

[themess]

I've been wondering how glycerine might work, based on the chemistry.

Oils are hyrdophobic, meaning that they repel water.

Glycerine, like water is hydrophilic, meaning that it likes water.

Hydrophobic materials and hydrophilic materials don't mix well. Oil and vinegar in salad dressings separate quickly, unless surfactants are used to coat little drops of one material with molecules that can mix with the other material. Detergents have a chemical structure that is hydrophobic on one end, and hydrophilic on the other, to do just that.

Rubber is almost entirely hydrophobic. That is why water and glycerine should not penetrate it. If carb boots would absorb glycerine, they should also absorb water. Think about the implications when riding in the rain.

The three primary causes of rubber hardening with age are continued vulcanization, oxidation, and loss of plasticizers.

Continued vulcanization: Rubber starts as a gummy substance. Chewing gum is literally rubber, unvulcanized rubber. Long, slippery molecules slide past each other. To keep rubber from changing shape too much, the long slippery molecules are attached to each other. That is called cross linking, or vulcanization. Sulfur is the cross linking chemical in many kinds of rubber. Add a little bit of sulfur and the rubber compound will be pretty soft, like a balloon or a garden hose. Add more and it will be stiff, like a suspension bushing. Add a lot and it can be a bowling ball.

For reasons of chemistry, not all of the sulfur added to rubber reacts with it chemically in the hot mold. Over ensuing months and years, the unreacted sulfur continues to react, forming more cross links and making the rubber harder.

Oxidation: Oxygen and ozone react with rubber, making it harden and sometimes forming more cross links. Rubber compounds are usually made with antioxidants and antiozonants. Those compounds eventually are used up, and the rubber hardens.

Plasticizers: Many rubber compounds contain plasticizers, to make them more flexible. Those compounds are usually oils and waxes. Some can evaporate, and some can oxidize. Think of a five year old bottle of cooking oil.

Wintergreen oil is functioning as a plasticizer. It can't undo cross linking and oxidation. It can act as an internal lubricant, permitting some more slippage between rubber molecules.

Many other molecules, such as xylene and toluene can do the same thing, but at the cost of weakening the rubber greatly. Those chemicals will also evaporate out of the rubber quickly.

Wintergreen oil seems to be at a very nice place for carb boots.
> It softens rubber enough to get some more years out of boots
> It doesn't seem to make them deteriorate
> It is safe to use.
> It is cheap and easy to find.

Any decent rubber chemist could find a better compound that wintergreen oil, but it wouldn't be cheap or available at the local drug store.

[Grimly]

Glycerine could also be mixed with water for use as antifreeze.

From making biodiesel years ago, I have gallons and gallons of the stuff, thrown off as a by-product. It's pretty impure, but your mention there gives me an idea. At some point I'll be putting in a solar water heating panel or two and was thinking of either drain-down or continuously-filled (which would need anti-freeze). I'll have to try some out as sample and do some freezing tests, but if it works it means much cheapness.
I like that - neat.

[themess]

From making biodiesel years ago, I have gallons and gallons of the stuff, thrown off as a by-product. It's pretty impure, but your mention there gives me an idea. At some point I'll be putting in a solar water heating panel or two and was thinking of either drain-down or continuously-filled (which would need anti-freeze). I'll have to try some out as sample and do some freezing tests, but if it works it means much cheapness.
I like that - neat.

URLs

Glycerine as an antifreeze

http://www.orisonmarketing.com/IceclearHD.html

Company makes and sells glycerine antifreeze with all the necessary additives. Lowest possible freezing point in -31F. Note that standard ethylene glycol antifreezes can go much lower. Freezing point depression is the flip side of boiling point elevation. The greater the freezing point reduction, the greater the boiling point elevation. Introductory chemisty books explain it.

http://biodiesel.infopop.cc/eve/forums/a/tpc/f/739605551/m/2991028081

General article on purifying glycerine from biodiesel production. Removing the methanol is quite important. Methanol is corrosive to most types of rubber. A methanol-gasoline mixture is extrememly corrosive. And methanol is highly toxic to people, and is absorbed directly through the skin.

http://www.journeytoforever.org/biodiesel_glycsep.html

URL from the above article. Practical methods for purifying glycerine from biodiesel residue.

One more note: Carefully test any home-brew antifreeze before using it large scale and long term. Small amounts of residual contaminants, either acidic or basic, could easily corrode your solar panels. The savings from home-brew could easily be wiped out if the systems needs to be rebuilt.

[Grimly]

Good points there; thanks. I'll be taking it carefully and even if the system is strung together from recycled rads and re-claimed piping, it will be a pain to re-do it because of corrosion.
I'd thought of using the glycerine as simple fuel (it does burn nicely) but it seems a waste to simply put it up the flue when its other properties might be more usefully applied.

[SVSooke]

A bit of an update.Wintergreen oil is not a snake oil cure for renewing boots.Had to take the carbs out of the 85 750 and the boots are softer now than when I installed them.Pretty cool stuff IMHO.

[WilliamGLX81]

Any chance this would help with leaky boots? Mine are both hard and one is a little leaky. Is the hardening responsible for leaking? It seems like the rubber has become delaminated from their metal mounts.

[Ton1959]

The boots come loose from the metal so no point trying anything to soften them. After 20 or more years you just have to buy new ones. I did think for a short while to weld a new metal pipe to the flange and then work with a rubber hose. But that also means lots of work so decided to order new boots.

[themess]

Any chance this would help with leaky boots? Mine are both hard and one is a little leaky. Is the hardening responsible for leaking? It seems like the rubber has become delaminated from their metal mounts.

If the rubber has separated from the metal, there is really nothing that you can do to fix it. Getting rubber to stick to metal and stay stuck is really quite tricky. I worked with tires and oil seals. The metal needs a special surface that can bond to an adhesive, or to chemicals in the uncured rubber. If any part of the system is dowe wrong, there will be no seal.

It might be possible to fill in the gaps and cracks with glues or sealants, but those are ot likely to last very long. Over the long run, you'll likely be better off to buy new boots and use your time in other, more productive ways.

[Ton1959]

No glue or filler will work to fill the gaps if you ask me. Get hold of the rubber and move it slightly and it will just fall of the metal part. On mine I noticed a small gap and all that was keeping those rubbers attached to the metal flange was really the tight gap between the air filter and the engine. So the rubbers didn't hold the carbs but the carbs held the rubbers from falling down.