Hammered Metal Work for the Home Shop
acid, solution and asphaltum
It is best to polish all the pieces before fast ening any of them together. Metal polish of any kind will answer the purpose.
Once the worker gets into the spirit of the work, many things such as match-safes, whisk broom holders, etc., which can be made with but few new operations, will suggest themselves.
Another method of treating sheet metal— and a simple one too—is to etch its surface by immersing it in an acid bath. The metal is cut to the size desired, after which the design is traced upon it by means of the carbon paper. Ordinary asphaltum or black varnish, such as can be procured at any paint store, is painted over that part of the design which it is desired to protect from the acid. The back also is cov ered with asphaltum. Two or three coats may be necessary to cover the metal properly—a small brush being used to apply it.
After the varnish is dry, the object is im mersed in a solution composed of nitric acid and water—somewhat more of water being used than acid. This solution should be placed in a stone jar, and should be kept off the hands and clothes.
The acid will eat the metal to a depth of one thirty-second of an inch in about four or five hours—depending upon the strength of the so lution. The metal should be examined occa sionally, and, when the desired depth has been reached, it should be placed in a pan of turpen tine, and cleansed of the asphaltum by scraping and swabbing.
Such articles as belt-buckles, corner-pieces for blotter pads or for book cover, copper pic ture frames, panels, covers for jewel-boxes, book-rack ends, etc., can thus be etched.
To color the metal, heat it quite hot, then dip it into the acid solution. Another color green—may be given by first cleaning the metal with the acid solution, then covering it with a thin coat of one part ammonia muriate, three parts ammonia carbonate, and twenty-four parts water. Added applications increase the depth of color.
Banana oil or lacquer applied over the metal will protect its surface from the air and keep it from corroding.