Plating silver onto glass

Letter 415

Plating silver onto glass

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I have been having problems plating silver on glass. I am using two solutions I found in a book. Solution A is composed of ammonium hydroxide and silver nitrate. Solution B is water and hydrazine sulfate. When I place the glass in the two solutions some silver plates out but the quality is poor (no shine) and the adhesion is very poor. I have tried cleaning the glass with ammonium hydroxide and drying. I have also tried lightly etching the glass in a strong solution of sodium hydroxide. I also tried heating the glass. So far, I have been unsuccessful. I do not want to use the "formaldehyde" process because I am nervous about fulminating silver which is one of the by products. Can anyone help me?

Leo Lamar

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You are already using "fulminate of silver" if you made a solution of silver nitrate and ammonia. The hazard only exists when the solution dries out. The dry crystals are very unstable, from what I've read. However I have no direct experience.

Moving on to applying silver to glass. The reaction bewteen silver fulminate solution and a reducing agent is widely used to coat a lot of items with silver. My company buys a commercially available system that works great. We coat wax shapes with silver this way, then plate copper on top. The trick is to apply it from a two headed spray gun. The silver comes out of one nozzle and the reducer out of the other and you place the item to be silvered where the sprays meet.

Bill Vins in hot humid Mesa (What a place-a) Arizona

Bill Vins
microwave & cable assemblies
Mesa (what a place-a), Arizona

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I know a person who has lost an eye because he allows dries out a solution containing silver nitrate and ammonia. Be careful!

Miguel Flesia
- Argentina

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To plate silver onto glass, you need to try vacuum deposition. The item to be coated is placed into a vacuum chamber, and metallic silver is vaporized within the chamber. A fine, shiny, tenacious layer of silver will deposit itself onto any glass item within a few inches of the silver. This is how mirrors are coated for lasers and telescopes. I suggest that you try any local college physics or astronomy department to see if they have a sputter coater.

Franklin Roberts
- Austin, Texas

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An amplification of caution written by other respondents: Use extreme caution as these silver fulminates are extremely unstable when dry or almost dry. They are extremely exposive and all due caution must be used.

Ed Budman
- Pennsylvania

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In my country a lot of copper (then silver ) is plated on glass for decorative parts. It is done by using a conductive paint. It is a very simple procedure.

Sara Michaeli
chemical process supplier
Israel

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You use a wrong method the right is the use of glucos+NH3+AgNO3+NaOH THIS METHOD will give you best result.

Maher Shaker Afifi
- Cairo, Egypt

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Ammoniacal Silver Nitrate Solution

20 drops Sodium hydroxide, 10%
20ml Silver nitrate, 5%
a few drops Ammonia water, 50%
30-40ml Distilled water

NOTE: All glassware should be chemically clean. This solution must always be freshly prepared.Add 20 drops of sodium hydroxide to 20ml of silver nitrate. Add 50% ammonia water drop by drop until there is a layer of granules left on the bottom of the cylinder. The ammonia water should be fresh and only a minimal amount used. Add distilled water to make 60ml. Prepare just before use.

1% Periodic Acid
1.0g Periodic acid
100.0ml Distilled water

2% Silver Nitrate
2.0g Silver nitrate
100.0ml Distilled water

Formalin Solution
30.0ml Stock formalin
70.0ml Distilled water

0.2% Gold Chloride
10.0ml Gold chloride, 1%
40.0ml Distilled water

5% Sodium Thiosulfate
5.0g Sodium thiosulfate 100.0ml Distilled water

STAINING PROCEDURE:

NOTE: It is absolutely essential that all glassware be acid cleaned with concentrated nitric acid and rinsed in several changes of chlorine-free water. 1. Heat slides on 60ºC to 80ºC hot plate for 10 minutes. 2. Cool. 3. Treat in periodic acid for 15 minutes. 4. Rinse in distilled water. 5. Stain in silver nitrate for 30 minutes. 6. Rinse in ditilled water.

If sections appear to loosen, blow dry and refix on hot plate. If sections loosen later, refix longer. 7. Stain in ammoniacal silver nitrate for 15 minutes. 8. Rinse quickly in distilled water. 9. Fix in formalin solution for 5 minutes. Wash in distilled water for 3 changes. Tone in gold chloride for 2-5 minutes. Wash in distilled water. Bleach in sodium thiosulfate for 5 minutes. Wash in distilled water for 10 minutes. Blow dry. Mount.

Mitri Maalouf
- Lebanon

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