Page:Popular Science Monthly Volume 91.djvu/146

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��Popular Science Monthly

��a circle, in which case it works with a rocking motion. The length of the segment should be sufficient to cover the surface to be grained, otherwise it will be difficult, but not impossible, to make the joint un- noticeable. A full circle roller is made as follows: Take a shaft and fix upon it, by mortise or otherwise, spokes of proper length, according to the size of the desired circumference, and around these spokes run or bend a strip of 3^-in. gum wood. If the ends of the shaft are smoothed off and allowed to extend about 4 in., handles will be provided toehold the roller in operation. Place around this roller the composition for making the print. A large roller may be made with a circular head of i-in. board having flanges from % to I x /> in. larger than the roller. Turn the roller over and stop all holes with plaster of Paris. The best way to do this is to run the plaster all around the inside of the roller. In the head of the roller, as it stands upright, cut three or four notches along the edge, about 1 by 2 in. to make places for pouring in the composition and for letting out the air. Make a long smooth strip of zinc large enough to cover the roller, rub it over well with grease or oil, then place it around the roller and pour in the composition. The oiled or greased side must be next to the composition. A very large roller will need collar bands to hold the zinc. Draw the zinc around the heads of the roller and pour in the composition through a strainer. Allow it to stand for at least 12 hours before removing the zinc.

Making the Roller

To make a smaller roller form it in a mold made of a light wood frame of the required size, set on a piece of zinc or glass. Pour the composition into it, then lay a piece of canvas on top of it. When cool, attach to a roller or rocker with tacks.

The composition is made as follows: Heat 12 oz. of raw linseed oil to the boiling point and add 1 oz. of chloride of sulphur. In another vessel dissolve 2 lb. of the best white glue and when melted add 8 oz. of commercial glycerine. Use as little water as possible in melting the glue. The best way to dissolve or melt glue is to pour enough cold water on the dry glue to cover it and let it soak over night. It will take all the water it can hold. Pour off the surplus water and add enough boiling water to melt it. To the glue add 8 oz. of com- mercial glycerine and mix well.

��Another formula is to dissolve or melt 24 parts of the best white glue and add to it 12 parts of commercial glycerine, which is cheaper than the drug-store brand. For a roller requiring from 10 to 15 lb. of com- position add Y /2 pt. each of molasses and raw linseed oil. To test the composition for consistency, cool a little of it and if it dries too stiff add a little glycerine; if too soft add more glue. This composition should be kept hot until used. Boiling it will do no harm, as this is inclined to drive off more of the surplus water.

Now for the Scraper

A scraper will be required and it is made as follows: Procure a piece of white pine board 12 in. long, 4 in. wide and Y% in. thick and make a groove in one edge of it 1 in. deep in which a piece of sole leather is placed after giving the depression a good coat of glue. The piece of leather should be about \]/2 in. wide and as long as the board. The edges of the board should be planed down so that it will not interfere with the projecting 3^2 in- of leather.

The printing color should be a little heavier than oil paint. It is composed of pigments ground in Japan. A board is the next requisite. It is made from the kind of wood to be imitated. Select as fine a figured specimen as possible and make it perfectly smooth and even of surface. This board must be 6 in. wider and 1 ft. longer than the circumference of the roller. Nail thin strips around the edges of the board, allowing them to extend 1 in. above the surface. Bore a y^-m. hole in one corner through which to pour off the liquids when cleaning it off. With the board ready, prepare a solution of I lb. of concentrated lye dissolved in hot water and pour it on the board's surface, allowing it to remain for 20 minutes. Then pour it off through the hole in the corner and rinse with clear water to remove the lye, after which flow a little vinegar water over it to neutralize the lye. The board is then left to dry out thoroughly, after which it may be lightly rubbed with fine sandpaper. The lye removes the soft fibers of the wood, leaving on the harder grain an effect similar to etching. The board is then ready for the printing process; but first try it by making a print from it on paper. If it shows an imperfect or faint print apply the lye solution again. Pour some of the printing color on the impression-board through a strainer. The printing color is made into

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