Cleaning mirrors

[mickoking]

Cobbers,

This is how I clean my mirrors and I have never had a problem with it.

Once you have removed your mirror give it a blow to remove the coarse debris of the mirror surface. Compressed air is your best bet, if you use a blower brush please remove the brush attachment as it can drag crap across the mirror surface.

Next place the mirror in a clean basin or sink and prepare a solution of warm water and a small amount of dishwashing liquid.

With some cotton buds gently clean the mirror in a radial action, ie from centre to edge until you think the mirror is clean.

As soon as you have completed the cleaning rinse the mirror with distilled water then put the mirror on it's edge to drain. At this stage you may use a hair dryer on a gentle setting. if there is still crap on your mirror repeat the process.

I hope this is of help.

[Starkler (Geoff)]

I feel gentle rinsing under a lukewarm tap could be a safer first step than compressed air. YMMV.

For the drying phase, I use the torn corner of a paper towel to wick up any remaining droplets and avoid any residue being left after they dry.

[TidaLpHasE]

I thought that compressed air contained impurities that could be placed onto your mirror adding to the mess rather than helping it?

I may be wrong, and thinking of my dslr sensor cleaning google searching tips.

[davidpretorius]

Thanks micko et al,

I am now confident it can be done, as usual with care!

[mickoking]

Originally Posted by Starkler

I feel gentle rinsing under a lukewarm tap could be a safer first step than compressed air. YMMV.

Sorry I forgot that step.

Blow, rinse, clean, Distilled water rinse, dry.

[ballaratdragons (Ken)]

I couldn't bring myself to use compressed air on a mirror, no way!

Blow compressed air through a clean cloth some time and see exactly what is flying out of the end of the hose under pressure!!!

Plus it forces particles across the surface of the mirror forming fine scratches, whereas just water lifts them off.

[janoskiss (Steve H)]

If you try all this, i.e., rinse and re-rinse with de-ionised/distilled water, then use paper towels + hair dryers + hanging out to dry, chances are that you will still see old marks and new spots of fluid residue on the mirror surface. Yes it sucks, but at that point you should lay down your sponges and concede that a good mirror with few marks and a bit of dust is what you have, and have a look through the eyepiece to convince yourself that it does not matter.

[asimov (John)]

Yeah, I won't be blowing compressed air across my mirror any time soon. I've never washed a mirror yet either. I think I would rather re-aluminise every ten years than bother washing it. It takes a lot of dust to affect the performance visually speaking.

[Starkler (Geoff)]

This is what makes sense to me:

1: Rinse under a lukewarm tap
2: A bit of a soak in lukewarm water with dish detergent. I wouldnt bother wiping at all unless its particularly bad.
3: Another rinse under warm running water to wash away the detergent and any softened deposits.
4: final rinse with distilled water and stand on end to dry in a safe place.

My mirror has a few spots from pollen or similar that must have settled when the mirror was damp and they wont budge by rinsing or soaking.
As they are tiny spots, I figure that any scrubbing to remove them is just going to cause damage and they may as well stay there.

[mickoking]

Originally Posted by asimov

Yeah, I won't be blowing compressed air across my mirror any time soon. I've never washed a mirror yet either. I think I would rather re-aluminise every ten years than bother washing it. It takes a lot of dust to affect the performance visually speaking.

As I said before I have never had a problem cleaning a mirror. If your gentle it should be sweet. Don't look at it as if your disarming a nuclear bomb.

[asimov (John)]

Sorry....my mirror is more delicate than any hair-triggered newk!

Thankxx fer postin' Micko!

[mickoking]

Just bein' a top guy.

[asimov (John)]

Hmmm. I have dudes requesting pics of my primary (yeah it's up for sale) I fiqure I need to clean it before taking pics.

1 question: Wouldn't it pay to shove the mirror straight in a sink full of warm water & let soak for awhile to loosen up dirt/etc. before hitting it with the jet of water from the tap?

[Starkler (Geoff)]

As long as you rinse and change the water before swabbing the surface with anything.
Dont want suspended crud particles scratching the surface.

[RAJAH235]

Yes. But if it's really dirty/greasy, you may have to use "non cellulose" cotton wool balls to help get the crud off. L.
ps. Don't forget the final rinse with distilled water in a squeeze bottle & blow drops off with a puffer (-brush).

Originally Posted by asimov

Hmmm. I have dudes requesting pics of my primary (yeah it's up for sale) I fiqure I need to clean it before taking pics.

1 question: Wouldn't it pay to shove the mirror straight in a sink full of warm water & let soak for awhile to loosen up dirt/etc. before hitting it with the jet of water from the tap?

The way I do it is to place the mirror in a perferated vegie bowl, at an angle
of about 45 degrees to the bench top. I then place this in the sink and start
the cold tap flowing so the water has a steady flow over the entire mirror
surface. You may have to adjust the mirror angle and flow of water to get
this right. Although it shoudln't be blasting the mirror (if it starts to splash off
the surface, your using to much power) a steady flow is required. I leave this
to sit for 5-10 minutes then I check to see if the large gritty bits are being
removed. If not I 180 it and start again. This way you dont have to wipe or
touch the mirror the water will do most of the work. Then with the water
flowing again I use a lens cloth dangled from my fingers with only it's own weight
and start drawing little circles from the center out. The cloth is never
pressured by you fingers or hand onto the mirror surface. The cloth literally
paraglides over the mirror surface knocking off whatever else maybe left
there.

I had an article on my method up on my website. But due to a change of
providers I'm yet to upload to the new area, beside I want to give it a lil
bit of an overhaul.

But I could send you a copy if you like.

regards

[iceman (Mike)]

In my opinion, there's too much emphasis placed on the danger of mirror cleaning and i've read many people all over the world taking all of these over the top precautions, and leaving years of built up crud on the mirror for fear of washing it off.

Again, it's only my opinion, but in my experience, it's really not hard to do and i've had no negative effect on my mirror or the quality of my view.

I've cleaned my mirror 2 or 3 times now (I've had the scope just over 12 months), as it can get quite dirty from dust, dog hair, dried up dew etc, and simply the light scatter from all these particles are bound to give a worse view.

Sure, I was a bit nervous the first time (because of all the tales of possible doom!) but if you treat it carefully, like you'd expect anyone to do when they're holding a mirror, then it shouldn't be such a scary thing to do.

Just take precautions -
1) Ensure your work area, sink etc, is prepared. Room to move, place to lay the mirror down, etc.
2) Take it out of the back of the OTA, just grab the mirror cell by the edges and ease it out backwards.
3) Leave the mirror attached to the mirror cell until you get it up next to the sink.
4) Undo the clamps, and just make sure you have a firm grip of the edge of the mirror when lifting it out of the cell. Then wrap your hands underneath as well.
5) In a sink with lukewarm slightly soapy water, let it rest for a bit, then using a cottom ball wipe lightly in strokes across the mirror, turn the cotton ball once and then throw away.
6) Angle the mirror and rinse with water from the tap for several minutes
7) Use distilled water, followed by blower brush or the corner or a paper towel to soak up the last drops that don't run off.
8) Let it dry, put it back in the mirror cell the same way you took it out, don't do the mirror clamps up tight - only very lightly (just) touching the mirror.
9) Back in the OTA the same way you took it out.

Don't forget to collimate, and then you're done!

It's not that hard to do, just be careful..

I'm sure people don't leave their eyepieces all cruddied up with dew stains, eyelash stains for fear of cleaning them, so why that attitude with the mirror? yeh if you drop it it's not going to be a good thing, but if you drop your $500+ nagler it's also not a good thing. And the mass produced GSO mirrors that most of us newt owners around here own, would cost less to replace than a nagler anyway

Anyway, just my opinion

[acropolite (Phil)]

While we're on the subject of cleaning, Dr Clay Sherrod of the Arkansas observatory has a cleaning formula and method for cleaning the corrector plates on SCT's. http://www.arksky.org/asoclean.htm

I tend to agree with most of what you said Mike, especially the fear most
folks have thinking of cleaning their mirrors. However I do think it is better to
have water flow removing grime before you attempt to wipe the surface. And
I dont think that is being to over cautious. Like you I've had my scope a year
and a half and washed the mirror about four times, usually before I want to
seriously try some planetary imaging. And my mirror seem none the worst for
wear, you just have to take care in handling it. From mirror cell to vegie bowl
for me, and I avoid touching the surface with your fingers

Using distilled water you shouldn't have to absorb any remaining droplets or
use a puff brush. I just sit mine outside, preferably in a gently wind. I also
mark the mirror cell and side of the mirror itself so I can replace it the
same way it came out.

Just my thoughts

regards, CS