This section is from the book "Soldering For Workshop, Farm And Home", by John Bonert. Also available from Amazon: Soldering For Workshop, Farm And Home - Information On Soft And Hard Soldering - Projects For The Workshop Explained And Illustrated.
The point of the soldering copper may become blunt after it has been filed a number of times due to the fact that with each filing more metal is removed from the narrow part of the sides than up where the sides are wider. At this time the writer wishes to beg the beginner not to follow the lazy practice of most tinner's and plumber's. You can find them using a soldering copper with a point so stubby that it will not fit into any corner. In just a few minutes the mechanic could draw his copper out and have it in good shape. Always keep in mind that the man who takes pride in keeping his tools in good condition will do the same with his work. The old saying that "a good mechanic is judged by his tools" is still true.
The copper should be drawn out to make the point longer. This is done by heating it red hot and placing one side of the point on an iron or steel surface and then striking the top side with a hammer as shown in Figure 3. The copper is rolled from one side to another as this hammering is being done. When the copper cools reheat it to a red heat and continue drawing it out until the point suits. This hammering should not be hurried by striking too hard or using a hammer that is too heavy. The copper will have to be kept red hot while this hammering continues.
Drawing Copper out to a longer point. FIGURE 3.
With a little patience the beginner can do this job. Of course as the shaping progresses the craftsman will have to use his own judgment where to direct the blows of the hammer. The shank of the copper will loosen up a little from the effects of the hammering but this can be corrected by resting the copper on the hard surface as shown in Figure 3. A few blows of the hammer will tighten the shank.
The information given up to this time has been for externally heated coppers or in other words coppers that are heated over an open flame or fire. The best method for tinning an electric copper is the one mentioned first by using rosin-core solder. The drawing out method explained should not be tried on an electric copper unless the tip is removed from the heating element. Any hammering should be avoided on account of possible injury to the heating element. The tip being quite short could only be held with great difficulty while the hammering was going on. Electric copper tips are of small enough diameter so that filing will keep the point long enough. The tips are screwed into the sleeve which houses the heating element. To replace a tip if it cannot be unscrewed, heating the copper will very often help to loosen it some. One other warning very important is never to put an electric copper into any flame or fire to hurry the heat. This may result in the loss of the heating element. The heating elements in many good coppers are guaranteed for as long as two years. With ordinary care it will do satisfactory work for a long time.