Aerosol dust cleaners for mirrors???

[Insomniac]

Are there any aerosol dust removers out there which can be used safely on mirrors to get rid of fine dust - the sort that only seems obvious by torchlight?
I imagine there must be traces of propellant in with the air, but have no idea if all these are chemically damaging to a protected aluminium coating.

On the subject, what about their use on lenses?? Sorry if this topic has already been 'done', as I'm sure it must!
Thanks
Chris

[Blue Skies (Jacquie)]

Sorry to say but you've never get rid of those 'torchlight dust' particles - some of them are tiny leftover pits in the surface of the mirror from the making. All mirrors I've seen have them, its a perfectly natural artifact of the mirror. This is why you should never check your mirror by torchlight for dirtiness, the only true way to gauge the dirtiness is in daylight. So put the torch away! You're giving yourself needless worry.

General information in the past was not to used canned air as the aerosol propellant can sometimes spit on the optics if its not used properly, but others have said the latest products are not such a problem. It has been discussed before, I remember joining in the thread at the time, so a search might bring the discussion to light and provide some more info for you as well.

[Waxing_Gibbous (Peter)]

I found them to be less than effective and often leave a thin film on the mirror. Also, its possible, though highly improbable, that you may crack an optic due to the temperature differential. Though this is more likely with a lens than a mirror.

I may get pilloried for this, but I use an electric leaf blower. It shifts a huge volume of air at ambient, with enough force to shift 99% of the smuts that collect on the surface.
It also cools my 8" Newt to within a degree of the surrounding air in a about a minute.
YMMV.

[gmbfilter (Geoff)]

Originally Posted by Waxing_Gibbous

I may get pilloried for this, but I use an electric leaf blower. It shifts a huge volume of air at ambient, with enough force to shift 99% of the smuts that collect on the surface.
It also cools my 8" Newt to within a degree of the surrounding air in a about a minute.
YMMV.

I use a Ryobi rechargeable
I shifts the boundary layer and allows the usual fans to keep up
For Dust
I have a cheap $99 bunnings compressor and filtered air supply to gently blow it away.
A little dust doesn't hurt

[DavidU (Dave)]

Interesting approach Pete. I should have a look at this...

Originally Posted by Waxing_Gibbous

I found them to be less than effective and often leave a thin film on the mirror. Also, its possible, though highly improbable, that you may crack an optic due to the temperature differential. Though this is more likely with a lens than a mirror.

I may get pilloried for this, but I use an electric leaf blower. It shifts a huge volume of air at ambient, with enough force to shift 99% of the smuts that collect on the surface.
It also cools my 8" Newt to within a degree of the surrounding air in a about a minute.
YMMV.

[wavelandscott (Scott)]

Don't shine a torch on your mirror...even when clean it will likely still look dirty. I beleive that a primary mirror can be very dirty before if will begin to degrade the views...

[Waxing_Gibbous (Peter)]

Originally Posted by gmbfilter

I use a Ryobi rechargeable
I shifts the boundary layer and allows the usual fans to keep up
For Dust
I have a cheap $99 bunnings compressor and filtered air supply to gently blow it away.
A little dust doesn't hurt

Cool! I'm not a nut case!
This method really works!
I did forget to mention I've got a vacuum cleaner filter attached to th inlet just in case an insect or leaf gets sucked-in. No one wants a beetle hitting their mirror at 50kph.

[leon]

If you want a fright shine your torch down the tube, it makes every that is clean look 10 fold dirty.

If it looks clean than it probably is just leave it, you need quite a layer of dust to affect your seeing.

Leon