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Old 16-10-2019, 03:36 PM
Wavytone
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Silvered mirrors, anyone ?

Stumbled on this...

https://sites.google.com/site/sprays...pemirrors/home

Long-lived silvered mirrors could be viable for those with big dobs - and the best part is the process is DIY, and low-cost.
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Old 16-10-2019, 04:19 PM
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Bobbyoutback
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Excellent !
The cost of recoating 12" & larger mirrors is so high these days , be good to see someone offer this service for larger mirrors .

Bobby .
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Old 16-10-2019, 07:50 PM
Wavytone
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You missed the point - the silvering process is something you do at home DIY - not a service - so no shipping involved.

What’s more it’s simple enough that you could easily do it annually on a cloudy afternoon, and be observing with an excellent coating, always.
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Old 16-10-2019, 10:58 PM
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billdan (Bill)
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This is the website where most astronomers buy their spray silver kits.

https://angelgilding.com/silver-on-g...ay-silver.html

Also note that silver can get contaminated quickly with oxidisation, so you will probably have to remove and re-spray every 12 months.
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Old 17-10-2019, 06:23 AM
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bojan
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My first 13cm mirror ("67?) was made from thick window glass (12mm) and silvered at local glass cutting - mirror making store, for very small fee (I could easily afford it with my pocket money income from parents), it lasted ~6 months when it became visibly brownish in colour, but still useable for Moon and planets.
With some sort of overcoat it would have been perfect... for the time being.
I even had a full list of chemicals used (nitric acid, cyanide etc... nasty stuff), they were available there and then in stores.... you just went there, lold them what you wanted, paid to the cashier and that was it.

Not sure how to get them now in Australia.
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Old 17-10-2019, 05:21 PM
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sopticals (Stephen)
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I've used the Angel Gilding spray silver products for several years now.Have silvered a number of mirrors 22" to 33". Find the coating is good for about 12 months. Couple of pics of mirrors. One of fresh coating and the other of a mirror coating 2 years old. Smaller mirrors up to 18" I can get Aluminized at a reasonable price.

Stephen.

Oops! picture of mirror with two year old coating was too big to upload.
Reduced size and now fits.

Stephen.
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Last edited by RB; 17-10-2019 at 08:07 PM.
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Old 17-10-2019, 05:41 PM
SteveInNZ
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Stephen,
What's the reasonable price for the 18" ?
Have you tried the Angel anti-tarnish stuff? I see that the bulk supplier doesn't ship overseas. How did you go with your own anti-tarnish experiments ?


Steve.
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Old 17-10-2019, 06:05 PM
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Merlin66 (Ken)
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Way back in the 60's we used to silver our mirrors at home following the old 20's techniques...ATM Book 1....
I still have some of the important recipes on record.
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Old 18-10-2019, 10:45 AM
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sopticals (Stephen)
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Quote:
Originally Posted by SteveInNZ View Post
Stephen,
What's the reasonable price for the 18" ?
Have you tried the Angel anti-tarnish stuff? I see that the bulk supplier doesn't ship overseas. How did you go with your own anti-tarnish experiments ?


Steve.
Hi Steve, what size mirror(s) are you wanting coated? I have had a few smaller mirrors (6" to 12 1/2") aluminized. Cost to me was NZ$75 plus GST for the 12 1/2". To find out more contact Andrew at "scopes@scopesnz.com"

Might add, that Andrew did a fine job on all the mirrors I sent.I did try Ceraclen "silver dip" when the silver started to "turn" (like zombie). It did remove the tarnish, but had to be careful not to not overdo otherwise coating can be "cut through". I do think it increased the life of the coating somewhat. Main problem seems, for me anyway, keeping the mirrors from repeat water condensation (the "killer"). Hard to do with "big glass".

No, haven't used the Angel anti-tarnish product.

Stephen.
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Old 18-10-2019, 02:24 PM
SteveInNZ
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Hi Stephen,


Thanks for the contact. I've sent him an email and we'll see what he can do.
I have a GSO 12" with lots of the coating missing and an 18" which is currently silvered but not yet mounted in a telescope.


Steve.
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Old 18-10-2019, 03:09 PM
JohnF (John)
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Here is a youtube on silvering a mirror. Do not claim that this is the only way, or is the best way -- Still trying to work that out, so don't know. Do need to do my diagonal.

https://www.youtube.com/watch?v=D1_-Xc2SpyE
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Old 18-10-2019, 03:23 PM
JohnF (John)
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By the way, my diagonal has minor surface scratches. And it is very dark, almost black.

That does make m wonder IF the mirror was silvered and that silver has tarnished -- Silver left can go black.

In which case, can I polish up that river with Silvo, etc.

Found this, half way down the page, Baking Soda method
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Old 19-10-2019, 09:01 AM
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sopticals (Stephen)
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Quote:
Originally Posted by SteveInNZ View Post
Hi Stephen,


Thanks for the contact. I've sent him an email and we'll see what he can do.
I have a GSO 12" with lots of the coating missing and an 18" which is currently silvered but not yet mounted in a telescope.


Steve.
Hi Steve, let's know how you got on. Price etc?

Stephen
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Old 19-10-2019, 12:57 PM
SteveInNZ
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He replied quickly and quoted the same price on a per run basis, rather than size. No overcoating.

He want's the glass cleaned of any existing coating and I've heard from elsewhere that the slightest bit of silver remaining can cause a blem in the aluminium.



I'm curious about the Angel product but at that price it's not worth silvering.


Steve
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