Thursday, December 6, 2007

ONE-WAY WINDOW GLASS

ONE-WAY WINDOW GLASS

Caution: Chemicals and ready-to-use solutions will cause

stubborn stains on hands and clothing.

Clean glass with soap and water, then rinse thoroughly, handling

the glass on the edges, only. Let glass dry.

Use a small mop, or make one with cotton on a stick. Pour a

little NITRIC ACID on the surface of the glass and spread it

around with the mop. Flush the surface with water, then place

the glass face down in a basin of clean water, to keep it clean

until you are ready to treat it.

Get five (5) clean glasses. In one make Solution A, by

dissolving one ounce of SILVER NITRATE in ten ounces of

DISTILLED WATER. Set aside one ounce of this solution to use

later. Then, with a medicine dropper and constant stirring with

a glass rod, "ammoniate" your Solution A, by adding, drop by

drop, some strong 10% to 26% AQUA AMMONIA. At first a thick,

brownish mass will appear, but as more ammonia is added this

will begin to thin out. Stop adding ammonia when the solution

has become just barely cloudy, not entirely clear.

Next, in a separate container, mix one ounce of caustic potash,

known as POTASSIUM HYDROXIDE, with 10 1/2 ounces of water.

Note: slowly add the caustic to the water. NEVER add water to

the caustic. Pour this solution into the ammoniated silver

nitrate solution and stir very thoroughly.

Then again, add strong ammonia water, drop by drop, until the

solution, just clears. Now, pour the remainder of the

Non-Ammoniated Silver Nitrate solution, this is the portion

originally set aside. The main solution would once again become

slightly cloudy. Make a solution of 1/2 ounce of GLUCOSE in ten

ounces of Distilled Water and stir it into the main solution,

which is now ready to use. This glucose is also know as

dextrose, or just plain corn sugar.

The "slivering" should be done on a level table. Remove the

glass from the basin and set it on edge to dry, then support it,

sterile face up, on the corners of four upturned identical

highball glasses, or the like. Place a small mirror, under the

glass, at an angle (this will enable you to see the reflection

of the silvering process so that you can stop at the right time).

Pour enough solution on the glass to cover it, leave it

undisturbed until the desired film of silver has been deposited.

By looking at the mirror which you have placed on the table, at

a slight angle, facing upwards, you are able to see the

reflection of the silvering process and stop at the moment when

the right degree of reflection and transparency has been

achieved. This will usually be about 20 minutes.

Then tip off the solution at one corner and thoroughly flush

with running water. Set the glass on edge and let drain dry.

WITHOUT touching the delicate film. When thoroughly dry, put on

a coat of clear VARNISH with a soft CAMEL-HAIR BRUSH, or better,

with a spray gun. When this dries, you may choose to further

protect the silvering by taping to the transparent mirror

another sheet of plain, clean glass of the same size.

In use, the light on the mirror side should be stronger than on

the back, and you should be able to see everything clearly

through the mirror from the back; while anyone on the other side

sees nothing but an ordinary mirror. Should you not be able to

see clearly through the mirror, you have allowed the silvering

process to continue too long. In order to achieve perfection,

practice with small mirrors, until you have the timing just

right. Such mirrors, as small as 8"x12" have sold for as much

as $12, which is of course far more than your cost to make.

Good Luck!

- Sold as information only -

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