Mirror Coating?

Regulus (Trevor) · #1 05-05-2014, 09:48 PM

Is there anywhere in Oz that does telescope mirror coating?

mikerr (Michael) · #2 06-05-2014, 08:01 AM

Trevor, this is the only one I know of...

http://www.saintech.com/

and this thread ...http://www.iceinspace.com.au/forum/s...light=saintech

Michael

Tinderboxsky (Steve) · #3 06-05-2014, 10:56 AM

Trevor,

This firm in Hobart does mirror coatings as per their website. I don't know if they do and/or have any experience with curved mirrors for telescopes. Might be worth checking.

http://www.longmanoptical.com.au

Cheers

Steve.

Regulus (Trevor) · #4 06-05-2014, 12:13 PM

Thx Mike and Steve.
I think Longman contract out but won't say who to so I can go direct.
They also contract out for other things. I had hoped the would make me an ED doublet or triplet for the sw120 I now have for sale.
Trev

cometcatcher (Kevin) · #5 06-05-2014, 01:49 PM

Astro Optical Supplies do mirror coatings. http://www.astro-optical.com.au/mirror.php

I used their service a lot in the 1990's when I made a bunch of mirrors.

Satchmo · #6 07-05-2014, 12:25 PM

I always try to warn people about Astro Optical just in the sense that they will not get a modern service . The technology in their old coating plant goes back to the 60's or 70's - they cannot do a protective overcoat and a protective overcoat is industry standard now . Don't listen to anyone who says your mirror will get ruined in stripping the coating later on - just ask a professional who knows what they are doing ...

cometcatcher (Kevin) · #7 07-05-2014, 01:36 PM

That's correct, they don't do an overcoat. But my mirrors that I had done 24 years ago are still looking good.

Satchmo · #8 07-05-2014, 03:58 PM

Quote:

Originally Posted by cometcatcher

That's correct, they don't do an overcoat. But my mirrors that I had done 24 years ago are still looking good.

I'll hazard a guess you don't wash your mirror very often ...

cometcatcher (Kevin) · #9 07-05-2014, 04:11 PM

Once every few years. They generally don't need a clean as I store the scopes slightly pointed downwards so dust doesn't settle on the surface.

Regulus (Trevor) · #10 07-05-2014, 08:14 PM

Thanks for the replies folks, it has been helpful.

Part two of this question is: Do they grind the old coat off first, or over-coat it?

Satchmo · #11 08-05-2014, 09:08 AM

I mentioned cleaning as non overcoated surfaces degrade much faster when they are cleaned as increasing microscratching on the surface lets the moisture encountered in use straight under the coating . If you live anywhere near bushland there will be a bloom on Eucalyptus oil that needs to be dealt with at least 6 monthly . Breathe on the mirror and if the breath pattern is blotchy then you have an oil layer.

If the surface is not overcoated it is usually soaked in a weak solution of Caustic Soda . If Overcaoted uasually a weak HCl and Copper Sulphate after giving the overcoat a hand buff with cerium oxide to put cracks in the overcoat. The underlying aluminium coat then comes off very quickly.

Regulus (Trevor) · #12 09-05-2014, 10:26 PM

Thx for that info Mark.
The fellow at myastroshop mentioned a Chinese man in Sydney that did re-coating too though he couldn't remember the name. Said he had referred some IIS people to him and they had happy outcomes.
Wonder who that is?

MrB (Simon) · #13 09-05-2014, 11:05 PM

Quote:

Originally Posted by Regulus

Thx for that info Mark.
The fellow at myastroshop mentioned a Chinese man in Sydney that did re-coating too though he couldn't remember the name. Said he had referred some IIS people to him and they had happy outcomes.
Wonder who that is?

That may be C Qin, tho sounds like he may no longer be coating?
http://www.iceinspace.com.au/forum/s...ad.php?t=92288

Satchmo · #14 10-05-2014, 12:11 PM

Quote:

Originally Posted by MrB

That may be C Qin, tho sounds like he may no longer be coating?
http://www.iceinspace.com.au/forum/s...ad.php?t=92288

He does as far as I know but he waits until he has a bundle then ships them to China for coating so there may be a long turnaround.

Saintech in Taree have similar prices and a beautiful 32" capacity hi tech machine . Take advantage of this service while it is available !

torana68 (Roger) · #15 10-05-2014, 01:40 PM

Quote:

Originally Posted by Satchmo

Saintech in Taree have similar prices and a beautiful 32" capacity hi tech machine . Take advantage of this service while it is available !

Ill send mine there, my 12" was accidentally sent there (not by me, long story) and work done before I found out, he didnt charge anything for something that he could have so thats a vote form me.