Instructables

Make Glass Mirrors With Silver Nitrate, Sugar, Ammonia and Sodium Hydroxide

video Make Glass Mirrors With Silver Nitrate, Sugar, Ammonia and Sodium Hydroxide
How to make a mirror silvering solution from silver nitrate, ammonia and sugar.

Glass surfaces can be given coatings of silver that make them into mirrors.

WARNING: Perform the whole experiment in less than two hours. This is because the solution generates highly poisonous silver nitride on standing. Also, the solution will give off ammonia when heated so you'll need to do this outside, in a fume hood or in a well-ventilated area. And wash away all chemicals with lots of water.

Get one gram of silver nitrate and one gram of sodium hydroxide. Then add enough water to both to completely dissolve them. Mix them together and youll get a black precipitate of silver oxide. Then add enough ammonia to completely dissolve the silver oxide. Add four grams of sugar and mix well.

The solution will deposit silver coatings when its heated. If you heat it in a glass container it will deposit silver on the inside of the container. To deposit it onto a glass pane you can put the glass into a tray with solution and heat the tray from below. But do not let the solution boil. Boiling tears the silver off the surface.

Thin layers of silver can be wiped off with a cloth if the silver goes where you don't want it. Thicker layers can be removed by applying hydrochloric acid.

This process produces a back reflective mirror, which is what most household mirrors are.

If you need to silver larger pieces of glass, or need thicker layers, just scale up the solution.
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donaldhu8 days ago

Hi can I do this on plastic?

n/m i read the comments. ill try it

n/m i read the comments. ill try it

abinc4 months ago

I have a large mirror that has water damage along one edge. If I scrape off the damaged area and use electrical tape to build a "dam" along the edge and the undamaged part of the mirror, can I apply the silvering solution and heat it from above with a hair dryer or a household steam iron (held over the area) to fix the silver to the glass? What is the grey coating on the back of mirrors? Is it silver oxide or a deliberately applied protective coating?

It is given a coating of paint to protect the silvered layer. It is not silver oxide.

It is given a coating of paint to protect the silvered layer. It is not silver oxide.

It is given a coating of paint to protect the silvered layer. It is not silver oxide.

Hi

I want to start doing this process in South Africa, they call it Chrome Spray on please can you help me.

many thanks

kind Regards

slawson96 months ago

Hi, I am an art student and interested in creating a mirrored pattern/drawing on to glass. I wondered if you could help. Can the solution be painted on to glass rather than submerging the glass in to the solution? Or can the silver coating on the glass be etched away either physically or with another chemical? I hope you can help, many thanks, Sarah.

OceanusEva1 year ago
Question, do you think the same effect would work on metal (on one side)? Would it still be reflective on the visible side?
Mr. Apol4 years ago
Does this coating conduct electricity? If so, it seems like an excellent way to make large Leyden jars . . .

Paul
It ought to. It's metal. Also, even silver OXIDE is conductive, so if it tarnishes, it isn't ruined.
mcshawnboy4 years ago
Can you explain how to make "Front surfaced mirrors" used in kaleidescope building?
Turn over a back-silvered mirror and you get a front-silvered mirror.

Silver tarnishes, though, so your kaleidoscope will slowly go black.
mastergabe1 year ago
hi NurdRage I was looking for some silver nitrate online when i realized how expensive it is and that it would be cheaper to make it from scrap silver but i could not find any scrap silver. It would be great if you made a video on how to check for presence of silver like the video on how to check for lead with potassium rhodizonate.
jnasrallah1 year ago
Could you lay a larger pane of glass flat on a table and pour on the solution? If so how thick of a layer of solution would you need? Also, how do you dispose of any excess solution?
kvalmoth1 year ago
Can you touch it when it's dried? Will it harm the skin?
08377171 year ago
Is there a way to do this if i'm using silver sulphate instead of silver nitrate?
Hi, i just had a go at this process, with no success :(

I am trying to discern what part of my process was the least scientific!

1. I mixed the AgNO3 with Drain Cleaner (Sodium Hydroxide, with some unspecified filler, and aluminium granules which i took out).
It immediately went all grey and curdled, but not quite so dark as the solution in the video. I used tap water.

2. it dissolved back to a very slightly brown/clear liquid with the application of Ammonia (25% solution.. the best i could get)
I take this as evidence that the chemistry is going alight so-far..

so i put it on the hotplate (a glass container placed in Boiling water to cap the temperature) and it proceeds to go dirty brown and stay that way... twice in a row.

Do you think

A: the AgNo3 is off, its straight from a factory sealed test tube, what is its shelf life?

B: my shoddy sodium is not so strong OR it came with too much Aluminium and spoiled the reaction? maybe substituted it or, bound to the silver making the black murky result
C: Do i have to heat it harder faster longer- maybe the water diluting the ammonia took it a long way off from being a saturated solution, is that part of the plan or is it irrelevant??

Please Help! I am an amateur at chemistry :)
A: not likely, as a dry salt the silver nitrate is pretty stable, especially if dry.

B: Possibly, it would be better to buy a $2 container of pure caustic soda drain cleaner (keep the lid on when not in use, it sucks in water from air)

C: Gentle heat is all that is needed,

Most likely problem: chloride in the tap water or caustic soda, causing the silver to precipitate as white (or pale yellow) silver chloride. Use distilled or deionised water (from automotive store, for batteries or radiator topups) or very clean rainwater. I go through gallons of the stuff in the lab, for every solution. I also triple rinse any glassware being used for silver solutions.

Adding just enough ammonia to just dissolve the brown silver oxide is the way to do it.
NurdRage (author)  oliverkellow2 years ago
You forgot to add in sugar.
Oups, i forgot to WRITE that i added sugar... 4g as requested, well mixed.
Sorry.

I boiled a away for forty minutes, and got a oilslick like layer that came off on my finger.
Its hard to tell from the video timelapse, did you take an hour, or is it a 2 min reaction I should be expecting.
Does the fluid stay dark when the silver is all dropped out?

I was wondering if its worth doing all my remaining AgNo3 at once ´to get a thick shiny coat, or is there a saturation point relative to the Sodium Nitrate?

Thanks for the speedy reply!

Oliver
NurdRage (author)  oliverkellow2 years ago
oil slick doesn't sound right.

your drain cleaner might have had a detergent that's interfering with your process.

The fluid should go creamy as the silver particles become big enough to reflect light..
j5_taylor2 years ago
do you think that this would still work if you were to use silver acetate instead of silver nitrate?
rahaffasheh2 years ago
Hello(:
Me and my friend are planning to do this experiment as a science fair project and need some help with the explanation..
So can you please give a scientific explanation for this experiment explaining the reaction and how the mirror is formed? (and maybe why we chose the materials that have been used..) anything you may now about it...?
We've been searching alot and can't find the right explanation..
please respond as soon as possible..
thank you (:
NurdRage (author)  rahaffasheh2 years ago
research "Tollen's reagent" the chemistry is the same.
76543213 years ago
Server not found at nurdrage.com :(
NurdRage (author)  76543213 years ago
yeah i canceled that hosting. Thanks for pointing it out! i'll fix the video description.
i noticed that too! it is still not fixed in other videos!
PS1185 years ago
Is there a way to disolve the silver off an existing mirror to reuse with this method?
wobbler PS1184 years ago
You don't need to use anything sophisticated or acidic, just metal polish and a bit of elbow grease. The metal layer is very thin and very easily removed with Brasso or similar, leaving the glass untouched. I used to make mirror photo-frames by masking off the mirror and rubbing away where I wanted it to be seen through to the photo at the back. (it was the 70's after all!- the 1970's that is, I ain't that old.) I've not tried this with acrylic mirrors though it may still work. If the silver is covered with paint or some protection, you'll need to remove this first before the Brasso will work. I used to just scrape it off with a razor blade. I don't think they'd invented paint stripper back then.
NurdRage (author)  PS1185 years ago
Yes! Soak the mirror in hydrochloric acid and the metal will dissolve off. If the back has been painted for protection then you might need to use a paint stripper to take the paint off before you can use the hydrochloric acid. The metal might not be completely removed in one run, just take it out and rub off what you can with a cloth before dipping it back in the acid or stripper.
rimar20005 years ago
Please tell me that this can be done on plastic. Any plastics: PVC, polyester, mylar, polycarbonate, etc.. I need it for a solar cooker. I am using glass mirrors, but they are too heavy.
. A mirror silvered on the front should work better for a solar collector (if that is an option available to you).
. aluminized mylar might work, but probably won't be very rugged.
Front silvered mirrors are perfect for an optical and protected application. A solar cooker is permanently exposed to the elements: rain, sun, dust, dirt, and surface abuse. Aluminized mylar is too thin, I need some self-standing and stiff, as 1 or 2 mm thickness.
NurdRage (author)  rimar20005 years ago
I've thought about the problem. How about chrome plating? You get your plastic and apply a very thin coating of conductive ink, rub off the excess and shape your plastic, then dip the whole thing in a chrome plating bath and plate on a layer of shiny chrome, or nickel (since nickel is less toxic to work with). It has been done with plastic, works on small scales, and doesn't require exotic equipment or apparatuses, just chemicals and a power supply. And if done right the surface produced will already be a high-quality front-surfaced mrror without the need for additional polishing. It;s not used for large scale production of mirrors because aluminum vapor deposition is still cheaper. But if you're going to small scale then this might work for you.
My final design of mirrors arrangement for solar cooker contains 85 pieces, totaling 1 square meter. I could try that of the chrome/nickel plated. But, does not require a further thorough polishing? I was like two hours trying to polish an aluminum sheet and all I got was a negligible improvement. I need a mirror finish.
There are a couple of processes available that will put a chrome-like layer onto plastics. Chromed lamp housings and the like on motorcycles, for example, are typically not chrome plated at all but are "chrome" painted ABS plastic. One (but by no means the only) process is called spectra-chrome.

These processes are expensive to buy and set up, but not at all expensive to get done for you. From memory, spectra-chrome only costs a few dollars per square foot.  Google "spray chrome"

Probably a bit late for you now, given the date of your post, but getting a mirror finish on Aluminium is very possible.  I will be putting an instructable together very soon on polishing metals.
Never too late, thanks, very much. My solar cooker is hung at the rear balcony, waiting my free time for resume the mod.
NurdRage (author)  rimar20005 years ago
yeah, no further polishing needing. You need a very special blend of chemicals in order to do this but what happens the metal fills the trenches of the surface first while it plates so it essentially smoothes itself out the more metal you put on it. Even if the original piece is scratched up to begin with the final piece will have a more even coat of metal than before. It can only fix small micron-level scratches but for the most part, you can get mirror shine without polishing. chemical blend must be perfect though but this is what they do in the auto industry.
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