G’day;
As someone mentioned earlier there are two liquids called oil of
wintergreen these days. As Pat Hicks said in a post today, the
original really was a natural oil obtained from the bark of the Red
Birch. The synthetic stuff is methyl salicylate and not an oil; it is
miscible with water - an oil isn’t.
Wanna make it? It’s easy.
Put some pure methyl alcohol (methanol) into a flask, dissolve in
some salicylic acid and slowly add a little concentrated sulphuric
acid; it will get very hot. Now fit a water cooled condenser on the
flask and heat it for some time. As the liquids boil and react
chemically, the vapour (steam) will condense back to liquid and run
back into the flask. After some time, pour the liquid into a
distillation flask, connect the condenser to the side tube, put a
thermometer in the neck of the flask through a cork, and distill the
methyl salicylate off at the right temperature (look it up; I’m too
lazy) It will smell very much like Wintergreen oil but it is only
the pure essence, the active ingredient of Red Birch bark used in
liniments.
And that, my dear metalworkers, really IS poisonous! And it
wouldn’t be much of a lubricant. If you want to lubricate gravers,
burrs, etc, use something else - olive oil for instance. Or better,
the white water-oil emulsion that engineers call cutting oil, and
use for lathe work and milling; pumped in a continuous flow over the
cutting tools. Many garages will sell it.
Johnb rides again: he now had a Mobility Scooter he calls Redd. He
swapped it (in effect,) for a well wrecked car. “Hi Ho, Redd,
Let’s hit the trail (footpath)!”
Cheers for now,
JohnB of Mapua, Nelson NZ