Take 12 inches of 1⁄2-inch strong lead pipe and square off the ends with a rasp. Take the shave hook and scrape the center of the pipe perfectly bright; a space 3 inches each side of the center is correct. The size of the joint when completed should be 21⁄2 inches long. If we should undertake to wipe the joint with the pipe in the present condition, the solder would adhere to all the pipe that was shaved bright. Therefore, we take a piece of paper sufficient to encircle the pipe twice and after putting paste on one side of the paper wrap it around the pipe so that the edge that is cut straight and even is 11⁄4 inches from the center of the pipe. Another piece of paper is pasted on the other side of the center leaving a clean, bright space of 21⁄2 inches. All the pipe should be covered with paper except the 21⁄2 inches in the center.
The most practical way is to take two common red bricks with the 2 by 8 face down and place them 9 inches apart. Lay the pipe on the bricks and place a weight on each end. The solder will drop on to the bench, so it is best to place a piece of paper or a pan of black iron under the pipe to catch the solder that drops. The pan or paper can then be taken up and the solder put back into the pot without waste. A cast-iron pot holding 15 pounds of solder is then placed on the furnace. When the solder has melted and has reached 500° it is ready for use. This can best be determined by putting a piece of paper in the solder. If the paper scorches, the solder is at the right heat; if the paper catches fire, it is too hot.
Now take a 3-inch ladle and heat it over the fire and then dip it into the solder and skim off any dross that may have collected.
With the ladle full of solder in the right hand and the large cloth or the catch cloth in the left hand, begin to drop the solder on the joint. The cloth should catch all the solder as it falls off the pipe. If hot solder is held against the bottom of the pipe, it is heated to the proper heat. Always begin to drop the solder on the paper edges, then drop the solder on the joint itself. Bear in mind that the solder should not be poured on, but dropped on slowly. After the first few drops do not drop the solder directly on to the lead pipe but on to the solder previously put on the pipe. This will save the pipe from burning through. The pipe must be the same heat as the solder before the proper heat is obtained for good wiping. The beginner should practice dropping the solder on the joint, catching the solder and working it around the pipe. By doing this, one becomes familiar with the feeling of hot solder, which is the secret of successful wiping. When the solder works easily around the pipe, drop the ladle and take the smaller wiping cloth in the right hand and with both cloths draw all the solder on top of the pipe. With fingers on the corners of both cloths, clean off the left-hand edge and with the right hand draw the surplus solder across to the right-hand edge. Next, clean the right-hand edge of the joint pushing the surplus solder onto the cloth in the right hand. Work this solder on to the bottom of the joint. Now discard the catch cloth. Holding the wiping cloth with the index fingers on lower opposite corners, shape the under and front side of the joint. With the middle fingers on opposite lower corners of the cloth shape the back and top. Keep the index and middle fingers on the edge of the cloth and the edge of the cloth on the edge of the joint. This position together with the size and shape of the cloth will give the joint the desired form and appearance. Particular attention is called to the position of the fingers as shown in the figure.
The last wipe should be a quick stroke coming off of joint on a tangent. If the solder is at right heat, the cloth will not leave a noticeable mark. If, however, the solder is too cold, a ragged edge will result. Sometimes a cross wipe is made for the last stroke and a good finish obtained.
The above procedure of wiping will be found to work out very easily if followed closely. Do not pour the hot solder onto the cloth as the cloth will burn through and soon be useless. A little more oil should be put on the cloth after using it for awhile. The cloth should be turned around and the opposite side also used. The cloth will last considerably longer if sides are changed frequently. The solder should not accumulate on the pan, but should be continually put back into the pot. The "metal," as solder is sometimes called, should never be allowed to become red hot.
The above method of preparing pipe is suggested for beginners only and will be found to be a great help to them. In actual practice the joint must be prepared differently. The method used in trade is as follows:
The joint is used to join two pieces of lead pipe. Take two pieces and rasp the four ends square. With the tap borer clean out the end of one pipe a trifle, then with the turn pin enlarge this end just a little as shown in the figure. Then rasp the edge off about 1⁄8 inch as shown. Take the other piece of pipe and rasp one end as was done in the cup joint, making it fit into the first piece. Then place the two ends together and with the bending iron beat the pipe, making the joint as tight as possible.