The fold may then be completed with the mallet if it is desired to close it up against the tin. To form a right angle the folder is not completely closed. A little experimenting with a piece of scrap tin will show how far to close the folder in order to obtain a given angle.
Fig. 53.
Care should be taken to set the gauge B parallel with the holding bar A. The folder is ordinarily set at ¼ inch. This is the width of most of the folds made in the tin. This simple machine will save much time in tin working and one should be purchased if possible. It is practically the only way a long fold in a narrow strip of tin may be made accurately.
The folder may be used to fold down the two long sides of the chassis, the ends may then be turned down over the edge of a block as the ends of the long folds will prevent placing the short folds in the folder. Narrow strips of tin may be folded over and hammered together with the mallet. These strips of tin may be slipped over the sharp edges at the bottom of each side of the chassis, thus making the edges very strong and removing the danger of cutting the fingers. [Fig. 51], D, shows an enlarged view of a corner of the chassis with the folded tin strips slipped over the lower edges.
These narrow folded strips are very easily made on the folding machine. Cut two strips of tin ½ by 12 inches and set the folder to fold ¼ inch, place the tin in the folder and fold it over. Remove it from the folder and hammer it nearly together with the mallet and then place a separate strip of tin in the folded part and continue hammering with the mallet until the folded tin is closed in on the inside or inserted strip of tin.
The folded strip is then ready to slip over the edge of the side of the chassis and to be soldered to it in several places; that is, the folded strip need not be soldered to the chassis continuously, but may be held in place by soldering about every four inches.
The two short strips of tin ½ by 4 inches should then be cut, folded and soldered in place at the short ends of the chassis. (No sharp edge should be left about a tin can toy when it may be avoided by folding or covering.)
A long narrow strip of tin is rather difficult to fold without the use of a folder, but it may be done with the mallet and block as follows: