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 m

tals 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.:

Metal Melting 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.

  1. First, in a cast-iron pot melt the lead to about 800°, 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.

  1. 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°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.

  1. 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.

  1. 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.