by Graham Forsdyke
国厂精品114福利电影THE FOLLOWING is a description of the japanning or, as we would call it now, stove-enameling process applied to sewing machines, and tells how the black finish and decorations were obtained.
The story is taken from an American sewing-machine trade journal, The Sewing Machine Advance, of May 1880.
Very few of our readers have ever seen a japannery, or know anything about the process undergone by a machine in being japanned, and a brief description thereof will doubtless interest many of them. We are indebted for information concerning these matters to Mr. E S Hastings, an experienced sewing machine japanner, who has recently engaged in the business in this city at No. 51 South Jefferson Street.
The plant or equipment of a japannery consists principally of the baking ovens, of which there must be at least two, the japan oven and the varnish oven, the sizes of which are regulated by the class of articles to be operated on and the quantity to be done at a time. A brick oven 8 x 10 feet and 7 feet high will take in about 500 sewing-machine frames at once.
Imagine a small, square, brick house with an iron door and without windows or aperture of any kind for the escape of heat, set in this a cast-iron furnace with a pipe leading through the solid wall for the smoke and gas to pass off through. Building a fire in the furnace of hard coal or coke, and keep it going at full blast until the furnace is red hot all over, then open the door and step in to see how they bake japan on cast-iron, that is if you can stay long enough to see anything. We tried it once but got out just in time to save being baked into roast greenhorn.
Hot! We think so! We have been in some warm places, but were not to be reckoned along with. it was a shot as ----, well, you know the place where all bad sewing-machine men will be japanned with sulphur when they die.
The ovens are fitted up with iron racks, on which the articles to be japanned are ranged tier upon tier, or are suspended from hooks ranged along upon iron rods placed across the ovens.
Japanning plain heads
The heads are japanned in separate parts, such as the frame, the balance wheel, the side of arm, the bobbin winder, etc, etc. They go first into the hands of a workman for the "ground work". He puts on a heavy coat of japan with a brush and they then go into the japan oven where they remain overnight in a heat of about 350 degrees.
国厂精品114福利电影The next morning they are taken out of the oven, and when cooled are rubbed down with lump pumice stone to remove all lumps and smooth the surface; another coat of japan is then put on and they go back into the oven for another night's baking. The next day still another coat of japan is put on and still another night's baking is undergone, after which they are rubbed to a fine surface with find ground pumice stone on rages.
The frames and such parts as require ornamenting and striping then go to the ornamenter, whose skill is greatly depended on to make a good-looking job. Taking fine camel's hair brushes he deftly and with remarkable rapidity lays on the designs and stripes with sizing of a peculiar composition which, after drying a couple of hours or so, acquires a certain "tack" or particular stage of gumminess and is then ready for the gold leaf.
This is at once carefully laid on and adheres firmly to the sizing, but not to the bare japan, and where the superfluous leaf is rubbed off the designs and striping are brought out in relief. If the designs be flowers or landscapes, or anything requiring shading, the shading is then put on in colors to suit the style of ornamentation required.
The heads then go into the varnish oven for three or four hours' baking in the heat of about 150 degrees, after which they are washed clean with cold water and rubbed well with clean soft chamois skin. A coating of fine, clear copal varnish is then brushed on and they go again to the varnish oven for a final baking of 12 hours in a heat of about 150 degrees. This process completes the plain heads, but half- pearled and full-pearled heads require additional processes.
国厂精品114福利电影The pearl comes in thin pieces or scales, and the finer qualities are quite costly. The pieces are cut to any desired shape and when the first coat of japan is put on, the pieces of pearl are laid on the japan while it is in a soft state. The machines then pass through the same series of processes as do the plain heads, except the two additional coats of japan are put on and baked each time, thus requiring much additional time and expense on the pearled heads.
When the last coat of japan has been put on and baked, the japan then covers the pearl, but it is rubbed carefully off the pearl with lump pumice stone, bringing out the pearling and making a smooth and level surface. The machines then go to the ornamenter as before.
国厂精品114福利电影This is the finest process known in the trade. After four or five coats of japan have been applied in the ordinary way, it is then polished to a very fine surface with rotten stone and the bare hand. The ornamenter then flows the surface with a solution of water and isinglass -- or gelatin -- and after covering the surface with gold leaf, allows the solution to drain off. when dry he pencils the design on the gold leaf with asphaltum. The superfluous gold not covered with the asphaltum penciling is then washed off with water, which does not affect the asphaltum.
Then the asphaltum is washed off with turpentine, which does not affect the gold, leaving the design wrought out in bright gold. The machine is then varnished and finished in the usual manner.
Some machines are ornamented with transfers, by what is known as the decalcomania process. This is a much cheaper mode of ornamentating than by hand, and carries an inferior look to the experienced eye.
The printing process
This is another rapid and cheap mode of ornamenting, where the designs are generally cut in wood on metal, and a cast taken off in plaster. A composition of glue and molasses is then made and run into the cast, forming a stamp with which the designs are printed on the machines in place of being penciled on by hand.