Articles by Rick Glawson
Glue Chip - Standard Method / Glue Chip - Rawson Evans Method / Glass Silvering / Angel Gilding Process / Lead Nitrate Deposition / Hydroflouric Acid/Mica Glass Embossing Process / Guide to Laying Abalone / Material Safety Data Sheet for Hydroflouric Acid
ANGEL GILDING PROCESS
Please read through the instructions thoroughly and follow the procedure to the letter. Although not difficult, the steps and sequences set forth are important and not without reason.
All chemicals when not in use should be kept in the refrigerator or a cool dark place. Let them warm to room temperature before use if refrigerated.
You will need to obtain the following; 3 Household variety spray bottles, 1 Galion of steam distilled or demonized water, 3 One-quart size plastic seal able containers, Disposable latex gloves, An electric orbital sander or car polisher with a felt or cotton blanket pad and an electric hot glue gun for selective gilding.
CONTENTS OF THE KIT ARE AS FOLLOWS
TWO - 8oz. Bottles "PURPLE" gold solution (Pre-diluted
and ready to use)
Put on gloves as the gold and silver chemicals will stain your skin. If your skin does become stained, household bleach will remove gold (purple) stains, and silver (brown) stains can be removed with the provided silver strip. In both cases, wash with soap and water afterwards. Maintain a clean work area and keep all chemicals away from children and animals. The varied contents are no more toxic or corrosive than household cleaning products but as such should be stored safely.
GOLD SOLUTION- The "Gold" solutions (purple) are
pre-diluted and READY FOR USE. Just pour into your dispenser marked "GOLD".
SILVER- Using the provided graduated measuring cup, fill and pour ONE OUNCE (30 ml, ml and cc are the same) of the GREEN silver concentrate from it's 2oz. Bottle into your 1st quart bottle you obtained. Now add 32oz. of distilled water, cap it, shake well, and label it "SILVER". Wash out the measuring cup thoroughly with tap water.
ACTIVATOR- Next, fill and pour ONE OUNCE of the BLUE silver activator into your 2nd quart bottle along with 32oz. of distilled water. Cap, shake well and label it "SILVER ACTIVATOR". Wash out the measuring cup again as before.
REDUCER- Now fill and pour ONE OUNCE of the RED silver reducer (depositing agent) into your 3rd quart container and add 32oz. of distilled water. As before, cap and shake well and label it "SILVER REDUCER". Rinse out your measuring cup again with tap water and put it away with the 3 silver concentrates for next time.
SILVER STRIP- Add the entire Orange/Black contents of the poly bag into one of your spray bottles along with 16oz. of regular tap water and shake. It is ready for use and has an indefinite shelf life. There is no need to refrigerate it.
TIN SOLUTION- Stannous Chloride. This is made up fresh before use as it perishes within a few hours after dilution. Mix one scoop of tin crystals (approx. ½" on the end of the provided ice cream stick) with 8oz. of distilled water in a dedicated spray bottle. Shake it well and mark as "TIN". Always rinse out the spray bottle well before making up a new batch. When not in use, keep container tightly closed and away from strong sunlight.
CERIUM OXIDE- There is no pre-mixing required.
ALUMINA POLISHING POWDER- Add enough tap water to the container it comes in to produce a wet paste. Ready for use, indefinite shelf life.
SPRAY WATER BOTTLE- Fill with distilled water and mark it as such.
GLASS PREPARATION FOR GILDING
Cleanliness is the key word here. Obviously if dirt, oil or any cleaning compound is left on the surface, it will give you an uneven and splotched gild. We first remove any oil, grease or loose dirt from the surface with Bon Ami or some dish detergent/water mix with a little cerium oxide sprinkled on for abrasion. Apply with paper towel or sponge, scrubbing, as you would wash your car. Rinse thoroughly using tap water and dry with a clean paper towel.
The next step is VERY IMPORTANT as it gives the glass surface "tooth" on which the gold adheres. Using the container of Alumina Paste, apply a dab or two onto the glass with a little tap water. The most efficient method is to use a small electric orbital (jitterbug) sander with the sandpaper replaced with a piece of felt or blanket. Adding additional water as necessary to keep a wet slurry, work over the surface for a minute or so. You could use a hand pad and a lot of elbow grease, but it's not near as efficient as using the sander. Float glass, (which is 90% of the commercially used glass today) is manufactured with as close to an optical polish on the surface as possible. This causes difficulty in achieving good adhesion. Common cleaning abrasives including Bon Ami, Pumice, and Cerium Oxide, are softer than the glass, which has a hardness of 5 to 5.5 on the Mohs scale with 10 being diamond, the hardest. The best effort with these products only gives you clean glass. The provided Alumina powder has a hardness of 9 (same as sapphires) yet has a particulate size of 3 micron (approx. 2000 grit). It microscopically scratches the surface well beyond the naked eye. A lack of tooth will cause the gold film to lift off the glass at a certain thickness or in some cases not allow it to deposit at all. In these days of high technology it is advisable to abrade all glass prior to ornamentation. Once the surface is well abraded, rinse well with tap water and a damp paper towel and avoid touching the cleaned surface.
DAM BUILDING FOR SELECTIVE GILDING
The best device we have found is a common hot glue gun. The tan or yellow colored glue sticks have better adhesion than the clear or white ones. In either case don't skimp on the bead around the area to be gilded. Later on if you find a smaller gun to be insufficient, an industrial version is available from the 3M Company. Squeeze an even ¼" wide bead around the glass perimeter or if the gilding is limited to a selective area, approx. 1" away from that portion. If the project must be gilded completely from edge to edge, as in a beveled or nipped edge piece, eliminate the dam but make sure the edges of the glass are clean and oil free.
NOTE: From this point on, any time you rinse your glass, you may use regular tap water as long as you finish it off with distilled to eliminate any tap water contamination. This will save on your distilled water cost.
Take your "distilled water" spray bottle and thoroughly wet the prepared glass. Hold it up vertically and shake off the excess water. Now using the "Tin" spray bottle, apply a wet coat over the glass. If you observe any repelling of the tin, saturate a piece of clean cotton with the tin and swab over that area. Be careful not to touch the surface with your fingertips. Let the tin sit for a minute or so then rinse, first thoroughly with tap water followed by a rinse of distilled water. Allow a pool of water to remain on the surface of the glass until you are ready to pour on the gold. DO NOT allow the surface of the glass to dry.
NOTE: A good working area for gilding is a plastic tub with several strips of wood laid across the top to level your glass on. It is not environmentally or legally permitted to pour gold or silver chemicals into the city sewer. Save all chemical runoff in your gilding tub and allow them to evaporate there. Saving the evaporated sludge in a separate container takes up little space and can at a later date be turned into a refiner that will extract the precious metal for a fee.
For our example we will gild an area of one square foot. Squeeze up 10 ml of Gold solution from the dispenser and pour it into a plastic cup. Now squeeze up 10 ml of Gold Reducer and pour into a separate cup. Always keep these cups rinsed clean between uses and never allow the same cup to be used for Gold and Silver. If when dispensing and pouring chemicals into a cup you find the solution turning black, a mix up has occurred. Don't argue with yourself, throw it out and grab a new cup. It happens to us all from time to time. Go back to your wet panel and shake off the excess water. Now take your two cups and rapidly pour one into the other and back again. ALWAYS pour the Reducer into the Gold, not vice versa. Box these together 3 or 4 times then quickly pour the mixed solution onto the glass surface. On panels of approx. 4 Sq.Ft. or larger, it's advised to mix the two chemicals by swirling the Gold around in the one cup and rapidly pour the Reducer into it. I generally pour around the perimeter first, then towards the center. Gently rock the panel from left to right and front to back making sure the panel is fully covered with the liquid. Being transparent, it is hard to maintain visual coverage without the rocking and is quickly apparent if you have sufficient solution. If not, quickly add some more. Being confident your panel is well saturated and level, let it set quietly for deposition, only occasionally rocking it to assure even coverage. Depending on the temperature and the humidity, the deposition time can be anywhere from a few minutes to a half hour or so. The process LOVES hot surroundings. Shop temperatures of 80 degrees and above make for glorious gilding sessions.
You will at first see a darkish film develop, where light can still pass through it. As it further deposits, and starts to reflect light, it takes on a golden copperish appearance. The coating is sufficient when you can only barely see your hand when placed underneath the panel. If there is any lifting of the gold, the cause is poor original cleaning or lack of surface abrasion. Pour off the spent solution and rinse the panel thoroughly with tap water, front and back. Follow this rinse with distilled water to swill off the tap and place it back in your tub.
The Gold layer at this point is very delicate and translucent, and may appear to have dark areas. These are usually thinner deposited spots and you are seeing the darkness of the tub shining through. We apply a layer of silver behind it to give it a little more durability, opacity, and brightness.
For each square foot of area to be silvered (calculated from the previous gilding step), use one ounce (30ml) each of the 3 diluted silvering chemicals (Silver, Silver Activator, & Silver Reducer). Measure them out separately and pour into marked plastic cups. Now pour them together into a larger cup, swill around, and flow onto the gilded panel as you did the gold. The mixed silver solution is nowhere near as trigger happy as the gold, so you have plenty of time for application. It is best to have all the chemicals measured out and ready to mix so you can make a smooth transition from your cleaned and tinned glass to completion. If any portion of the gild has started to dry, mist on some distilled water and shake off before applying the silver.
It takes much less time for the silver to react, usually a minute or so. It is not necessary to apply a solid silver layer. Approx. 50/50 in color or a pale gold in appearance is sufficient. If the silver layer appears dark and discolored, poor rinsing is the cause. Normally this doesn't effect how it looks from the front, but in the case that it does, spray it with your silver strip, rinse it well and resilver. The silver strip will not affect the gold. When you approve of the silver layer, pour it off, carefully remove the glue dam (if used), and rise thoroughly with tap/distilled water. Now you can either stand it up on edge to drip dry, or blow-dry it for speed. Don't let it lay flat when drying as the water puddles, when dry, could show through to the front. When it is dry and shiny, it's ready to back-up. The metal surface is just as tender as water-gilded leaf, so avoid any conditions that would scratch it.
BACK-UP & REMOVAL
The surface can now be backed up in the same manner as regular window work. You may silkscreen or pounce and letter the graphics by hand. If this is to be a solid mirror, coat the back with a good enamel or asphaltum. For signage and ornamentation, use an approved back-up paint such as "Fine Gold's" as the excess metal must be removed safely.
We have found that a bit of "Splash" surfactant
with a lightly water moistened cotton pad used alternately with a dry
pad will remove most of the excess. If the silver was applied heavy and
is being stubborn, a little silver strip will aid. As with cleaning up
regular leaf work, don't over saturate with moisture. Think elbow grease
primarily. When only a slight "halo" remains, a touch of Bon
Ami on your pad will finish it off.