telescope cleaning

[Craig_R_Oliver]

Hi I'm just wondering if any one knows what's the best thing to use to clean telescope lenses and the main mirror?

[Jim Steele]

Generally I'd avoid cleaning the lenses and mirrors unless absolutely necessary but if they are filthy you can use IPA (Alcohol) with lens cleaning tissue.

Id put a drop on the tissue and drag the tissue across without rubbing as the grit that gets picked up may damage the mirror with repeated passes. Discard tissues between wipes for the same reason

[baggywrinkle]

Use one of those camera air puffer things to blow away dust, keep the lens caps on after use and between uses in the field.

[Moonshane]

Generally I'd avoid cleaning the lenses and mirrors unless absolutely necessary but if they are filthy you can use IPA (Alcohol) with lens cleaning tissue.

Id put a drop on the tissue and drag the tissue across without rubbing as the grit that gets picked up may damage the mirror with repeated passes. Discard tissues between wipes for the same reason

I'd never clean a mirror like this. much better like this

personally, I rarely clean mirrors, in fact I generally only do so when selling as people seem to want clean mirrors. I have not cleaned my 16" mirror since I bought it in April 2011.

[crashtestdummy]

i would avoid using anything alcohol at all cost as it could damage the coating on the mirror.as in the above youtube video but i would avoid using cotton wool as its how i scratched my mirror.standard cotton wool is highly abrasive,only the expensive medical grade stuff is useable.i personally soak as in the video after using a rocket blower then i resoak 2 more times then i use wet kitchen role under its own weight across the mirror then rinse again.works for me but i cant recomend it fully as some kitchen rolls may be abrasive.if in any doubt leave well alone

[Moonshane]

there are 'infinite' ways to clean a mirror. my method when I bother does not involve touching the surface at all.

1. remove mirror from telescope and cell
   
2. put the mirror in tepid water with a few drops of washing up liquid.
   
3. leave for as long as you like, a few minutes is fine
   
4. swish the water about to remove stubborn dirt
   
5. take the mirror our and place in bath on a towel, leaning against the side of the bath (I am assuming an acrylic bath)
   
6. rinse the mirror off with tepid water preferably through a shower head
   
7. final rinse with RO water from an aquarium and rocket blower off the residual droplets
   
8. put back in scope when dry and collimate.
   
9. if anything is not removed by the above, you may risk damage to the coatings if you try harder
   

[Philk_80]

If something didn't come off using this method, what further would you recommend Moonshine?

[Moonshane]

leave well alone. you'll never see it at the eyepiece and are likely to damage the mirror if it's stubborn.

[Craig_R_Oliver]

Ok thanks every one. I don't plan on cleaning it unless i have to. But at least i know how to clean it safely now

[Zakalwe]

Be careful using washing up liquid. The stuff is full of salt, which can easily eat aluminium coatings.

[Stargazer_00]

the water in my area is so hard I wouldnt use it. If and when I decide to clean my mirror im going to go buy a few litres of evian

edit, and a brand new bowl to swish it in, and a brand new towel to stand it on while it rinses.

Would a hair dryer work to dry it off?

[baggywrinkle]

Be careful using washing up liquid. The stuff is full of salt, which can easily eat aluminium coatings.

True. I know it sounds that there is no connection but I used to clean air dead weights (piston gauges in the US) by only using pure baby soap, unperfumed. It left no residue which could affect the air gap between the piston and cylinder, they were micron sized gaps. So pure baby soap should be ok for a mirror.

BTW a dead weight is a primary standard pressure device.