Rev. 2003-04-30, 2005-07-10, 2006-08-21, 2008-02-13. 2009-08-21, 2010-11-27, 2012-08-22
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This page is a collection of items I have
collected about mirrors and silvering glass objects. I have not
yet done anything with mirroring, although I would like to.
Please note that modern serious mirrors (astronomical) are made
by applying aluminum in a vacuum chamber, so the techniques on
this page are for scientific and art glass, like insides of
Dewar vessels, thermos bottles, gazing balls, door handles, and ornaments. Please note that a
long time ago (200+ years) mercury was used in certain glassware so it is still called mercury glass
although all recent mercury glass is made by depositing silver from solution.
Mercury is not now used and is very
dangerous to have around (as in dribbles on the floor, etc.)
because the vapor does damage to people. Also note that the acids
involved are serious acids that will do serious damage. [edit 2008-02-13]
An ordinary flat mirror is made by taking good quality
glass and coating the back with a thin coating
of shiny metal, usually silver today. Then the coating is covered
with an opaque paint, usually black, to increase the reflection and that is
coated with a decorative paint, often grey, that is easier to clean. Old
mirrors often have engraved details in the glass making them worth preserving,
but the silvering has been damaged, usually by moisture penetrating the coating.
Removing the coatings must be done carefully to avoid
scratching the glass. 2006-08-21
Glass can be covered with a thin coat of silver or aluminum and then not covered with the paint used to make an opaque mirror. When this is done, the glass is said to be half-silvered or to be a one-way mirror or one-way glass. Because of these latter names, there are people who believe that a product exists which is always mirrored on one side and always clear on the other side, which is not true. The visibility through such a mirror/glass depends entirely on the lighting - those on the more brightly lit side will see the glass as a mirror and those on the darker side as a more or less transparent window. The silvered surface (and reflection) take out much of the light passing through, so the view through the glass is always darkened. If there is any light on the dark side, then it is possible to make out what is going on there from the bright side. Even if the dark side is completely black, some light is present having come through the one-way. Because the reflection is less than perfect, with experience it is easy to spot that a piece of mirror is half-silvered. Normally, because of its expense and fragility, users installing half-silvered do not even disguise the small mirror as being a real mirror - the reflection merely prevents people from easily knowing whether someone is behind the view port. It is now much cheaper to use reflectorized plastic film such as is used on cars.
Normally mirror silvering is applied to the back of the glass where it is
protected from touching. It is further protected and enhanced by painting
over the silvering with opaque paint that reduces further the light passing the
silver coating, making the reflection brighter.
From Ed Brice's column in the Ft. Worth Star Telegram, 2007-04-20, Q:" I have an antique mirror that needs to be resilvered. Is there anyone in the Fort Worth area who does that kind of work?" A:"My pals over at The Edge of Glass Art [9524 Semintal Drive, Crowley, TX 817-297-4404 ] will be able to handle all your resilvering needs. They also do beveling, carving and other thing that'll slice up your finder if you have no idea what you're doing "
Heck, here are some messages
Peggy; Silvering is not too difficult. When I worked as a scientific glass blower, we silvered the insides of Dewar flasks all the time (30 years ago). Cleanliness is important! We cleaned the glass with some rather nasty solutions. To silver we used a silvering formula from a scientific glass blowers book. It used a silver nitrate solution and a sugar solution. The silver ends up being deposited on the glass. As I recall, we kept everything agitated to get a good even coat and we used cooled solutions to slow down the reaction. Try looking in a university library for the formula and process. If you can not find it, I'll dig up my old books and look it up for you. Any silver deposited where you do not want it can be removed with acid. Good luck. By the way, do not get the silver nitrate on your hands - it stains! Jim
Subject: Re: MIRROR SILVERING-NEED HELP! From: firstname.lastname@example.org
(Scott Bartky) Date: Wed, 27 Mar 96 11:37:13 GMT
Subject: Re: MIRROR SILVERING-NEED HELP! From: mcFrenzy
<email@example.com> Date: Wed, 27 Mar 1996 09:47:44 -0500
Subject: Re: MIRROR SILVERING-NEED HELP! From: firstname.lastname@example.org
(William ) Date: 28 Mar 1996 05:24:47 GMT
Subject: Re: MIRROR SILVERING-NEED HELP!
email@example.com 3/10/98 mirror formula site http://www.grfn.org/~mickey
For making silver solutions: 4 ounces from #1, 4 ounces from #2
1-gallon silvering solution: 1 ounce silver 1 ounce sodium
hydroxide 2 6/9 ounces ammonia
SILVERING SOLUTION for GLASS ( http://www.dragonbeads.com/silverng.html)
WARNING - use of this is at your own risk - it involves chemicals that should be treated with respect. The writer and this website assume no liability for results.
First method is do-it-yourself - sources for "kits" follow these instructions: METHOD A This is the method we used for years at The University of Illinois. Its a 3 part recipe. I know there are other products out on the market. Because of the use of Silver Nitrate this process can be quite expensive.
A. Silver Nitrate (66.6 Grams) to, One liter of deminerialized
To do the silvering process:
I was also taught to let these the A, B & C solutions sit and cure for a week or so in a cold room/refrigerator. Don't let these solutions get warm it will speed up the silvering process and do not use too much ammonium hydroxide as it will coagulate and ruin the batch. ( I used a dropper or pipette) This has to be done in a well ventilated area for these are very strong chemicals.
Also silver nitrate will never come out of your clothes and takes forever to come off of your skin. Always wear gloves and protective clothing while doing this process.
Jan Singhass Scientific Glass Technology Lab (Shipping) 101 Daniels Hall (Mail Box) 8209 Dabney Hall North Carolina State University Raleigh, NC 27595
Shop: (919)-515-3562 Fax: (919)-515-7668
> ... makes a reference to a "spray silvering" process. A friend
Subject: Re: removing silver from
mirrors From: "Wm Kidd" <firstname.lastname@example.org>
Date: 19 May 1997 17:42:49 GMT Richard <email@example.com> wrote
in article 337F996D.9A2F1547@pitt.edu...
http://www.mirrorresilvering.com/ combines both.
Mirroring Glass Messages 4/16/96
<< If anyone can e-mail me steps to silver mirrors it would be appreciated. >> Check the archives for the group, it was posted a while back. A messy business that would probably be easier than trying to take it off.
We offer perfect cost-effective coating solutions for Mirror and Glass processing industry which meets International Standards.
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