For welding iron, a flux of white sand is usually used, this material being
placed on the metal after it has been brought to a red heat in the fire.
Steel is welded with dry borax powder, this flux being applied at the same
time as the iron flux just mentioned. Borax may also be used for iron
welding and a mixture of borax with steel borings may also be used for
either class of work. Mixtures of sal ammoniac with borax have been
successfully used, the proportions being about four parts of borax to one
of sal ammoniac. Various prepared fluxing powders are on the market for
this work, practically all of them producing satisfactory results.
After the metal has been in the fire long enough to reach a red heat, it is
removed temporarily and, if small enough in size, the ends are dipped into
a box of flux. If the pieces are large, they may simply be pulled to the
edge of the fire and the flux then sprinkled on the portions to be joined.
A greater quantity of flux is required in forge welding than in electric or
oxy-acetylene processes because of the losses in the fire. After the powder
has been applied to the surfaces, the work is returned to the fire and
heated to the welding temperature.
_Heating the Work._--After being scarfed, the two pieces to be welded
are placed in the fire and brought to the correct temperature. This
temperature can only be recognized by experiment and experience.
Pages:
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178