Re: Cleaning?

Be sure to read the MSDS carefully, especially
the parts about "explosions", "distant
ignition sources", and "sensitive to static
discharge." I've had the stuff flash and
explode while cleaning a mirror. Not something
I would recommend. If you've got a fire-proof,
static-free room with halon, then go for it.
But otherwise I'd leave acetone to the professionals,
and look to less reactive agents like 93% (or less)
alcohol. Or some of the enzyme based cleaners.

The other reason to avoid it, as if one needed
a second reason, is that it will dissolve most
of the stuff used to blacken lens edges. Unless
very careful, you can quickly get a black smeary
mess all over your nice lens -- one which will
make a finger print or water spot look like nothing
at all.

MSDS Acetone:

5. Fire Fighting Measures
Fire:
Flash point: -20C (-4F) CC
Autoignition temperature: 465C (869F)
Flammable limits in air % by volume: lel: 2.5; uel: 12.8
Extremely Flammable Liquid and Vapor! Vapor may cause flash fire.

Explosion:
Above flash point, vapor-air mixtures are explosive within flammable limits noted above. Vapors can
flow along surfaces to distant ignition source and flash back. Contact with strong oxidizers may cause
fire. Sealed containers may rupture when heated. This material may produce a floating fire hazard.
Sensitive to static discharge.

I believe the TeleVue site essentially says; "Use the fluid of your choice."

Regarding acetone, as John says, use it with great care. I sometimes use it to rinse mirrors but it do it outside.

For eyepieces, one has to be careful not only of any plastic but also of paint. Not all aluminum is anodized, some is painted, I think probably most brass and steel is painted. Acetone is not quite like MEK or Methyl Cloride as a paint remover but can dissolve paint. Nothing quite as counter-productive as putting a nice thin coating of blackening over eye lens.

I use either isopropyl or distilled water with drop of soap.

Jon