Ned Mantei <[email protected]
> wrote in message
> In article <[email protected]
>, "RMan" <[email protected]
> >I use an ultrasonic bath to clean parts. I immerse the part in a tub of hexane, and immerse that
> >tub in the ultrasonic bath for 10 min. Everything comes out sparkly clean, particularly chains
> >and cassettes.
> 1) I agree that hexane is a very good solvent for dissolving grease. However, it is also
> unexpectedly toxic. It specifically binds to a protein in axons (neurofilament protein), and,
> when used for cleaning bicycle parts, is especially likely to get at the motor axons that make
> your hands move. There is a disease called hexane neuropathy caused by exposure to hexane
> through the skin--see Google on "hexane neuropathy" for more information. I still use hexane,
> but only with rubber gloves and in a fume hood. I minimize contact with the gloves (not sure
> they aren't permeable) by doing the actual washing in a large screwcap plastic bottle (shaken,
> not stirred...). I also reuse as often as possible--I suspect that evaporated hexane is not
> good for the atmosphere.
> 2) Some years ago there was a thread in this newsgroup to the effect that use of an ultrasonic
> cleaning bath would lead to the part becoming brittle. "Hydrogen embrittlement" is the term I
> remember, although it isn't clear to me where the hydrogen would come from. Perhaps only a
> problem with aqueous solvents.
I don't know about the effects of ultrasonic cleaning on aluminum and steel, which constitute the
bulk of washable bicycle parts, but I have seen warnings about its effect on brass. Ultrasonic is
sometimes used to clean brass train models prior to painting and running the cleaner for too long is
known to make the metal brittle.