MIXTURES OF SOLDERS FOR SOLDERING IRON AND WIPING. CARE OF SOLDERS.
MELTING POINTS OF METALS AND ALLOYS
The importance of good solder, that is, solder correctly mixed and
thoroughly cleaned, should not be overlooked. Work is more quickly
and neatly done and the job presents a more finished appearance
when solder that is correctly made is used.
The solder used in the following work with the soldering iron is
called 1/2 and 1/2. This means 1/2 (50 per cent.) lead and 1/2 (50
per cent.) tin.
In the mixture of solder, only pure metals should be used. The lead
should be melted first and all the dross cleaned off. The tin
should then be added and mixed.
The solder to be used in wiping the joints in the following chapter
is a mixture of 37 per cent. tin and 63 per cent. lead. This is
called wiping solder.
The following table gives the melting points, etc.:
---------------+---------+------------------------------------------
| Melting |
Metal | point | Mixture
---------------+---------+------------------------------------------
Sulphur | 228 | Pure
Tin | 446 | Pure
Lead | 626 | Pure
Zinc | 680 | Pure
Fine solder | 400 | 50 per cent. tin, 50 per cent. lead (wt.)
Wiping solder | 370 | 37 per cent. tin, 63 per cent. lead (wt.)
---------------+---------+------------------------------------------
To recognize fine solder, run off a bar into a mold and let it
cool. If there is a frosted streak in the center, the metal has not
enough tin. The surface should be bright. To recognize wiping
solder, pour some on a brick. When this is cool, the top should be
frosty and the under side should have four or five bright spots.
The amount poured on the brick should be about the size of a half
dollar. If poured on iron, the metal will cool too quickly and show
bright all over the under side.
TO MAKE 1/2 AND 1/2 SOLDER OR PLUMBER'S FINE SOLDER.--The
possibility of getting pure clean metals to mix solder is very
remote. Old pieces of lead pipe, lead trap, old block tin pipe are
used to make solder when pure metals are not at hand.
_First_, in a cast-iron pot melt the lead to about 800 deg., or a dull
red.
_Second_, clean off the dross.
_Third_, add (to a 15-pound pot) 1/2 pound of sulphur in three
applications. Each time mix the sulphur thoroughly with the metal
with a long stick.
_Fourth_, add tin before the last application of sulphur. Mix
thoroughly.
_Fifth_, pour off two bars and look for the frosty streak in the
center. Add a little more tin, if necessary.
TO MIX WIPING SOLDER.--
_First_, proceed as described in 1/2 and 1/2, melting the metals
and _burning_ out with sulphur, adding the percentage of tin
according to the preceding table. Then test the solder for bright
spots on the under side.
_Second_, keep the metal thoroughly mixed when burning and keep
all dross cleaned off the surface.
The working heat of wiping solder is 500 deg.F. Sulphur is used to
collect all zinc and dross. The sulphur should come in contact with
all parts of the metal. This is why the metal should be stirred
when the sulphur is put in.
A few good points in the economical care of solder are listed
below.
CARE OF 1/2 AND 1/2 SOLDER.--
_First_, do not drop melted solder on the floor or dirty bench.
_Second_, use all small ends by melting on a new bar.
_Third_, put clean paper under work and use droppings.
_Fourth_, have the mold free from dirt when pouring.
CARE OF WIPING SOLDER.--
_First_, do not heat red hot.
_Second_, do not file brass where the filings will get into the
solder.
_Third_, do not allow lead chips to get into the solder.
_Fourth_, clean the solder occasionally.
_Fifth_, learn to distinguish solder from lead by its hardness.
_Sixth_, have different-shaped pot for lead and solder.
_Seventh_, do not _tin_ brass by dipping into solder.
_Eighth_, do not put cold or wet ladle into hot solder.
A pot holding about 15 pounds of solder is the size commonly in
use.