Copper may be raised to nearly a white heat before it will melt; brass, however, runs much sooner—at a yellow heat. Silver looks pink when “red-hot” if the flame has been moved away. It will melt before it gives a white glow. Gold changes colour very little before reaching its melting point, but then it collapses very suddenly. So use considerable care and manage your flame so that no thin part gets a sharp blast. Remember to move the flame right off the work for a fraction of a second every now and then. You will thus be able to see when any part is getting too hot.
In soldering a wire on to another part of the work you may have some difficulty in keeping the solder from running on to and thickening the wire. This is a particularly disagreeable habit, for it quite ruins the appearance of a twisted or plaited wire if it is clogged up in this way. To avoid this difficulty you must take care that the heat reaches the wire only through the work—not directly from the blowpipe flame itself.
