dusting your primary off with an air duster

[bomberbaz]

I recently bought some tins of compressed air to clean my pc and was wondering if these would be any good to blast over your primary to clean off some of the dust.

I qam not thinking of getting up close to do it but from a distance of around a foot just blowing it over to remove any loose stuff, being a flextube I have no problem getting so close so what does anyone think?

I am hesitant otherwise I would not be asking the question

steve

[Jonk]

Personally I would never used compressed air from a can or compressor to blow on optics.

Look for Giottos Rocket Air, these well brilliantly up close to a mirror or lens.

With a lens, blow using a rocket air then gently breath on the lens then wipe with a microfibre or glasses cloth.

With the mirror, just keep it dust free.

[kev100]

Hiya, I've used a can I'd air to clean my EPs, like you say, though, from 8-10 inches or so away, just to remove the loose stuff.

I can't see the same approach doing any damage to the mirror. I wouldn't do it often/regularly, tho. Perhaps just once if the mirror us particularly dusty, then keep it covered and clean as beat you can.

Kev

[laser_jock99]

We use air cans all the time to blow dust particles off optics. Just keep the can upright to avoid freezing liquid mixture blowing out. If the optic is small make sure it doesn't get blown away & don't use air cans on optics susceptible to thermal shock. Avoid touching mirrors unless it's the last resort- aluminium coatings can be easily damaged if the SiO2 coating is soft or poorly applied. A soft camel hair brush can be tried to shift particles that won't blow away first time. 

Use proper lens tissue if physical cleaning is required- but only one wipe then throw it away and re-start with a fresh piece. There's too much danger of wiping a trapped gritty particle repeatedly across the mirror! For this reason alone I'd avoid microfibre type cloths.   

[AstroAdam]

They're really not recommended for optics, as it's very easy for the propellant to be pushed out too. This wouldn't affect pc components, as it evaporates quickly. However, it does leaves really bad marks on optics, which can be more of a pain to clean off than the dust itself.

Even at a foot away, keeping the can upright, it can happen. I speak from experience...

[laser_jock99]

They're really not recommended for optics, as it's very easy for the propellant to be pushed out too. This wouldn't affect pc components, as it evaporates quickly. However, it does leaves really bad marks on optics, which can be more of a pain to clean off than the dust itself.

Even at a foot away, keeping the can upright, it can happen. I speak from experience...

It's good practice to do a clearing blast into the air to clear the pipes out of any liquid first. When starting a new can we always invert it and blast some liquid through first to clear out any oil residue etc from the valve assembly. To put my experience in context we get through about six 400ml cans a week cleaning optics at work.

[AstroAdam]

This is something I do, but have never had much luck anyway. What brand do you use?

[Daniel-K]

I recently bought some tins of compressed air to clean my pc and was wondering if these would be any good to blast over your primary to clean off some of the dust.

I qam not thinking of getting up close to do it but from a distance of around a foot just blowing it over to remove any loose stuff, being a flextube I have no problem getting so close so what does anyone think?

I am hesitant otherwise I would not be asking the question

steve

if its bugging you that much just wash it. i dont see what the big farce is about TBH ive washed loads of mirrors and they have all been fine. aslong as your prepped before making sure everything is in place i dont see what the big deal is?

[Qualia]

Steve, from time to time (once a year may be ) I use one of those pear shaped blowers and try to blow a little dust from the mirror. I really don't know how much I'm making matters better, but to my eye I can't see any diifference. If I get inspired I might wash the mirror this Xmas. It's been 2 years now with the 10" under all sorts of conditions and it is a little dirty.

[Peter Drew]

I would avoid compressed air, maybe OK in experienced hands but not worth the risk IMO. I would also advise not wiping any aluminised surface with a dry wipe. 

[laser_jock99]

This is something I do, but have never had much luck anyway. What brand do you use?

We use Pro Power brand either from CPC or Farnell

http://cpc.farnell.com/pro-power/ppc101/air-duster-400ml-aerosol/dp/SA01882?in_merch=Featured

[Austin]

I use a camels hair paint brush on the end of a garden cane to gently "tickle" off the big bits of muck and that's it. Im with danny too, if it's that bad, dont b scared to get the primary out and clean it.

[Dave In Vermont]

Whenever it is truly in need of clearing off dust, and/or an unknown, I remove the mirror-cell from the OTA (optical tube assembly or just 'tube') from my F/4 Newt. Then I use a camel-hair brush, such as that which is on the Lenspen cleaning devices. If it's got some dust that won't cooperate with the brush - which I use gently in one direction - I'll use a sterile cotton-ball from the druggist's shop. One direction only and one gentle swipe per ball, then a new ball, etc.

It's better to do with the mirror removed, I've found. I am quite well set to re-collimate the scope after replacing the now-clearer mirror. In fact I rather enjoy it!

Clear & Clean Skies,

Dave

[bomberbaz]

if its bugging you that much just wash it. i dont see what the big farce is about TBH ive washed loads of mirrors and they have all been fine. aslong as your prepped before making sure everything is in place i dont see what the big deal

Righto danny as your local come along and show me 

Seriously I will read up on whats required and I think either a gentle wash as prescribed by danny or maybe a camel hair brush clean is needed. I do need some stronger springs too so i think I shall order them first and then kill two birds with one stone.

The mirror does look quite dirty though for sure.

steve

[jason.p]

I use a camels hair paint brush on the end of a garden cane to gently "tickle" off the big bits of muck and that's it. Im with danny too, if it's that bad, dont b scared to get the primary out and clean it.

If you're doing this make sure the mirror is dry. I made the mistake of smearing it when it still had a residue of condensation on it. Consequently the mirror had to come out for a wash.

As above, mirror washing is nothing to be feared as long as good preparation and care is taken.

I know many will say not to clean unless absolutely plastered, but if you really can't live with it, get it out and wash it. (IMO!)

[bomberbaz]

Tried air dusting and it made little if any difference so a wash it will be, think I will flock it at the same time, another job I have been putting off.

I may as well re-mount the 100p mini-dob whilst at it, hehe once you start!

[Daniel-K]

steve if you buy the flocking from FLO make sure you use one of those hair rollers first. just run it over the flockig papper a few times to pick any lose stuff. if you dont and you clean wash your mirror, when you look at it next you wont be happy. take from me i know

you can pick up 5ltrs of disstileld water from halfors or asda for a few pounds.

[Dave In Vermont]

If you use a torch (flashlight) to look down the tube at the mirror, it will likely look like a battle took place on it. Even when it's sparkling clean. Use ambient light.

Clear & Clean Skies,

Dave

[jetstream]

I use the Rocket Blower gently just before washing my mirror. Compressed air may blow some sand or hard dust across the mirror and scratch it. Once Rocket blown, off the mirror goes into a soapy water bath, then a clean water bath, repeat and is finally rinsed with distilled water. Then left to dry at an angle. It seems to work well, no water spots or scratches.

I would not drag anything across my mirror dry, like brush bristles, just my opinion. The soap in the water lubes up any fines for when they are rinsed off, important. To each their own though.

[Jonk]

I completely agree with jetstream...that was the advice I found when I bought a couple of second hand scopes and had to clean them.