Page 269 - My FlipBook
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SOLDERS AND SOLDERING. 257
ratory, both for melting' metals and soldering-, is borax.
This substance fuses readily and llows freely when in the
molten state. The commercial borax contains water of
crystallization to about one-half its weight; it is the driving
off of this water which causes the puffing up or swelling of
the borax in soldering. This may be largely overcome by
using fused or dehydrated borax. Other fluxes and refining
agents are potassium nitrate (saltpeter), which yields oxy-
gen; murcuric chlorid (corrosive sublimate), or ammonium
chlorid (sal-ammonium), both of which yield chlorin
sodium chlorid (common salt), resin, powdered charcoal,
etc., are also frequently employed when melting metals to
protect them from oxidizing.
SOLDERS AND SOLDERING. 257
ratory, both for melting' metals and soldering-, is borax.
This substance fuses readily and llows freely when in the
molten state. The commercial borax contains water of
crystallization to about one-half its weight; it is the driving
off of this water which causes the puffing up or swelling of
the borax in soldering. This may be largely overcome by
using fused or dehydrated borax. Other fluxes and refining
agents are potassium nitrate (saltpeter), which yields oxy-
gen; murcuric chlorid (corrosive sublimate), or ammonium
chlorid (sal-ammonium), both of which yield chlorin
sodium chlorid (common salt), resin, powdered charcoal,
etc., are also frequently employed when melting metals to
protect them from oxidizing.
