For any but very small pieces of copper, you will need a strong heat source such as oxyacetylene. Note that in air it will take copper, even thin copper, a long time to cool from 800☏ or higher to the point where it can be handled. Extra safety precautions are necessary because of the high heat involved: you must place your copper on real firebricks, and keep flammables well away from the flames and the hot metal. borax is available in supermarkets and hardware stores, near the laundry detergentįor use on Copper only.This is based on patina 5.164 in Hughes and Rowe (p 280), but our formula is a stronger variant we adopted based on a mistaken formulation of the patina by our friend, the sculptor Martin Metal. This should be done under a fume hood and with eye and breathing protection. Either before or after brushing it, you can burn the patina with a torch. You may then go over the surface lightly with a scouring pad to take away some of the powdery residue, if you wish.
Once the color has achieved good coverage, let the piece dry out in the sun for a few hours, then wearing a mask and gloves brush off the wood chips, back into the pile for reuse. Usually it takes two to three days to develop a good patina on brass, if you are assiduous in tending it and filling gaps. We find that the patina only develops well on the upper surface where the chips and liquid are resting, so you will need to rotate the piece once its top is done to get each side in turn. Check once or twice a day to see how the patina is developing keep putting on more wood chips and/or patina liquid to fill gaps. Out of doors and out of reach of children, soak sawdust or wood chips with the liquid and bury the piece to be patinaed in the wood chips, and wet it down with more of the patina. Description:Īdd the ammonia and other ingredients to the water and stir until dissolved. This is based on patina 5.51 in Hughes and Rowe (p 280), but our formula (above) is three times the strength given there, for quicker application. The patina is very transparent, and must be built up slowly. In good ventilation, and wearing a face-mask, heat the metal with a torch until the solution-brushed on with a soft brush-steams off instantly. Description:Īdd the ferric nitrate to the water and stir with a nonreactive rod until the chemical is totally dissolved. It is the least toxic, and one of the easiest to use, of the many patinas which produce similar colors. This is patina 5.116 in Hughes and Rowe (p 296). If the color on the surface is accidentally burnt black with the torch, the patina may be simply reapplied to that area with good results. If the metal is overheated, the brush will stick and burn. In good ventilation, and wearing a face-mask, heat the metal with a torch until the solution-brushed on with a soft brush-steams off instantly, and leaves the color solid and dry on the surface. Grind the cupric nitrate in a mortar, add it to the water, and stir with a nonreactive rod until the chemical is totally dissolved. It is a traditional patina, and is found many other places as well. Our Dark Green patina, from which this formula comes, is Hughes and Rowe's number 5.117 (p 296). Take care not to burn the surface of the blue-green while applying the second layer.
This patina is much-used on bronze sculpture, but we currently use this patina only over a layer of blue-green. Grind the potash in a mortar, add it to the water, and stir with a nonreactive rod until the chemical is totally dissolved. The amount of potash can be varied in a very wide range to produce different densities of black. 50 grams Sulphurated potash (Liver of sulphur) Young gives this patina in his book, Contemporary Patination (pp 69-70), where he recommends different application techniques than ours, and suggests ways of getting many different color variations. Reapply gently, so as not to disturb the first layer, which will be powdery. Brush or sponge the patina all over the metal's surface, leaving it puddled all over the piece. They are to be used at your own risk.Īdd the chemicals to the water and stir with a nonreactive implement. NOTE: read all safety information and take appropriate precautions before mixing or using these formulas.
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