Horizontal Lap Seams.
This seam is prepared precisely as described for flat lap seams. The strips can be fastened to a board with a few tacks. The strips can then be supported in the position shown in Fig. 28. The burning is commenced, as before, at the side nearest the operator. The flame must be made as short as is consistent with the weight of the stock. It will be found to the beginner's advantage to have fusion take place slowly. The point of the inner flame is brought to bear on the outer edge of the lapped sheet and at an angle of 45 degrees. Both sheets should begin to brighten at about the same time. The melted drop must be driven against the back sheet by the force of the jet of flame, and if the sheets are clean fusion will take place quickly.
Fig. 28.—Burning a Horizontal Lap Seam.
The drops or beads of lead will appear very small on this form of seam, owing to that great obstacle, gravity, which causes the drop when melted to flow downward and so swell the seam. The drops, in common with other forms of lap seams, should be made short, letting each drop overlap the previous drop as much as possible. Great care must be taken not to weaken the seam, as shown at a. The beginner should strive to get the seams so that when cut into small sections each section will resemble the result shown at b.