Well I did it, cleaned the primary that is

[Keithp]

Well following on from my query about dewing on the secondary and the primary I noticed dew marks on the primary (the secondary is pristine). Just before dinner tonight I got the screwdriver and undid the screws and got it out complete in its cell. The dew residue left on it (8 months old) was quite apparent and I decided to clean it....If I was going to do any imaging tonight I was not putting up with that...besides which I like to get to know how things fit together....heh heh heh.. Carefully undid the screws on the outside of the tube, mounted on the tripod so it was at an easy working height (and balanced up).

Well I got 3 small bowls of warm water, first with 2 drops of washing up liquid in, second ..tap water, third distilled water.

I have two cloths which I use on the eyepeices I have, one came with a zeiss set of binos, the other a spectical glass cleaner from a well know store. Used the first cloth in the soapy bowl and poured the water over the mirror and gently stroked it over with the bino cloth, there were a couple of marks on the mirror that stood proud almost like something had settled on it..carefully scraped them off with a softened finger nail, while using copious amounts of the washing up liquid water and using the first cloth.

All marks removed, final swill off followed by the tap water to rinse. Tilted the mirror cell up and then rinsed off with the distilled water.

Left it for about 15 mins and then came back. The two clothes had been dried off using a hair dryer for a couple of mins then I looked at the mirror in day light with the sky and reflections, not looking too bad actually, maybe a couple of water marks left. Carefully with the first cloth, now dry I gently polished out any dry water marks left on the mirror and then finally finished off with the spectical glass cloth.

It is now very clean, no marks and is back in the tube...don't care it's done, is a lot cleaner than it was and is not scratched...I may have been lucky..

I know I might get shot down in flames for doing it...against all advice I've seen.

But it's done. I'll let you know if I have any problems following on from this..

Regards

Keithp

[Doc]

carefully scraped them off with a softened finger nail

maybe a couple of water marks left. Carefully with the first cloth, now dry I gently polished out any dry water marks left on the mirror and then finally finished off with the spectical glass cloth

You are braver then me. Mirrors are so easy to scratch.

Anyway well done and I'm sure the views will be brighter.

[Keithp]

Cheers Doc,

I'm just not putting up with dirty mirrors:eek:

I know everyone advises against it but it's a bit like having a hard drive fragmented...

The computer works, but you don't want it...

Regards

Keithp

[Doc]

Keith it was your wording of "carefully scraped them off with a softened finger nail" that just made me go OUCH.

I'm going to do mine in the near future as well, I'll let you know how I get on.

[Keithp]

Doc...

heh heh heh:D

[John]

I did my 12" a couple of months ago. I just used distilled water run acros the tilted mirror then I used distilled water soaked cotton wool to very gently (just the weight of the wet cotton wool really) to swab the mirror, discarding cotton wool after each stroke. Then rinsed again with distilled water and left to dry at it's own speed with the mirror standing on edge, on a towel. It came up really well - a few light water marks here and there but nothing to worry about.

It was a slightly delicate process but I'm glad I did it and won't need to repeat it for a long time. A 12", 30mm thick mirror weighs more than you think - Doc's 16" primary will require some careful handling !.

John