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.
Remove the wooden plug from the vent hole and place the hood on top of a hot stove or over a medium gas flame. In a short time some spots will begin to look dry. If any cracks appear mix the powder which has been reserved to a thin paste and with the fingers rub it into the cracks. It will require about one or two hours for the clay to harden depending on the heat applied. The heating process must be watched for if any clay should sag away from the metal it will have to be pressed back gently into position before it hardens. When dry, the lining will be as hard and well appearing as any fire brick. The hood can be fastened to the frame of the stove although it is giving good service just set over the burner.
1- The soldering copper must be clean and tinned at all times.
2- Try to use the proper flux for the metal being soldered.
3- Always wash work to remove zinc chloride.
4- Be certain that the surface to be tinned is clean.
5- After cleaning keep the fingers or any foreign substance from touching the surface.
6- The work must be heated above the melting point of the solder.
7- Use a copper sufficiently large to heat the work.
8- Always try to heat the copper with a blue flame.
9- Avoid resting the tinned point of the copper on a very wet surface. It may cause some solder to spatter about.
10- When floating solder, and a bright surface is desired, always apply some tallow before floating.
11-Always wipe the point of the copper with a cloth before attempting any tinning.
12- Avoid jarring an electric copper.
13- Avoid melting too much solder on a joint when tinning.
14- Be sure to brush molten solder in a direction where it will not do any damage.
15- Never dip a damp or wet article into a solder pot. It will cause the solder to spatter.
16- Avoid jarring work before the solder cools.
17- Have your work secured before soldering or brazing.
18- Never apply a flame to a tank or can which has contained a combustible liquid. Blow out any gas which may remain.
19- For convenience, small strips of solder can be cast by melting the solder from a bar with a soldering copper. Use a piece of angle iron held in the vise and let the solder drop into the trough. Best results will be obtained when the angle iron becomes warm. This method can also be used for salvaging small pieces or drops of solder and melting them into small strips.