LOAM.—Mixture of brick, clay and old foundry sand.
PARTING SAND.—Burnt sand scraped from the surface of castings.
BLACK WASH.—Charcoal, plumbago and size.
BLACKENING FOR MOLDS.—Charcoal powder, or in some instances fine coal
dust.
MIXTURE FOR WELDING STEEL.—One part sal ammoniac, ten parts borax,
pounded together and fused until clear. Then it is poured out and after
cooling, reduce to powder.
RUST-JOINT CEMENT.—(Quickly setting.) One part sal ammoniac in powder
(by weight), two parts flour of sulphur, eighty parts iron borings,
made into a paste with water.
RUST JOINT.—(Slowly setting.) Two parts sal ammoniac, one part flour of
sulphur, 200 parts iron borings. The latter cement is the best if the
joint is not required for immediate use.
RED LEAD CEMENT FOR FACE JOINTS.—One part white lead, one part red
lead, mixed with linseed oil to the proper consistency.
CASE HARDENING.—Place horn, hoof, bone dust, or shreds of leather,
together with the article to be case hardened, in an iron box; subject
to blood red heat, then immerse the article in cold water.
CASE HARDENING WITH PRUSSIATE OF POTASH.—Heat the article, after
polishing, to a bright red; rub the surface over with prussiate of
potash; allow it to cool to dull red, and immerse it in water.
CASE HARDENING MIXTURES.—Three parts of prussiate of potash, one part
sal ammoniac; or, one part of prussiate of potash, two parts sal
ammoniac and two parts bone dust.
GLUE TO RESIST MOISTURE.—One pound of glue, melted in two quarts of
skim-milk.
MARINE GLUE.—One part of India rubber, twelve parts mineral naphtha or
coal tar. Heat gently, mix, and add twenty parts of powdered shellac.
Pour out on a slab to cool. Heat to about 250 degrees and it is ready
for use.
GLUE CEMENT TO RESIST MOISTURE.—One part glue, one part black rosin,
¼ part red ochre, mixed with the least possible quantity of water; or,
four parts of glue; or, one part oxide of iron, one part of boiled oil
(by weight).