Cement For Mending Earthern And Glass Ware

1. Heat the article to be mended, a little above boiling water heat, then apply a thin coating of gum shellac, on both surfaces of the broken vessel, and when cold it will be as strong as it was originally. 2. Dissolve gum shellac in alcohol, apply the solution, and bind the parts firmly together until the cement is perfectly dry.

Cement For Stoneware

Another cement in which an analogous substance, the curd or caseum of milk is employed, is made by boiling slices of skim-milk cheese into a gluey consistence in a great quantity of water, and then incorporating it with quicklime on a slab with a muller, or in a marble mortar. When this compound is applied warm to broken edges of stoneware, it unites them very firmly after it is cold.

Iron-Rust Cement

The iron-rust cement is made of from fifty to one hundred parts of iron borings, pounded and sifted, mixed with one part of sal-ammoniac, and when it is to be applied moistened with as much water as will give it a pasty consistency. Formerly flowers of sulphur were used, and much more sal-ammoniac in making this cement, but with decided disadvantage, as the union is effected by oxidizment, consequent expansion and solidification of the iron powder, and any hetrogeneous matter obstructs the effect. The best proportion of sal-ammoniac is, I believe, one per cent of the iron borings. Another composition of the same kind is made by mixing four parts of fine borings or filings of iron, two parts of potter's clay, and one part of pounded potsherds,and making them into a paste with salt and water. When this cement is allowed to concrete slowly on iron joints, it becomes very hard.

For Making Architectural Ornaments In Relief

For making architectural ornaments in relief, a moulding composition is formed of chalk, glue, and paper paste. Even statues have been made with it, the paper aiding the cohesion of the mass.

Mastics of a resinous or bituminous nature, which must be softened or fused by heat, are the following:-

Varley's Mastic

Mr. S. Varleys's consists of sixteen parts of whiting sifted and thoroughly dried by a red heat, adding when cold a melted mixture of sixteen parts of black rosin and one of bees'-wax, and stirring well during the cooling.

Electrical And Chemical Apparatus Cement

Electrical and chemical apparatus cement consists of 5 lbs. of rosin, 1 of bees'-wax, 1 of red ochre, and two table-spoonsful of Paris plaster, all melted together. A cheaper one for cementing voltaic plates into wooden troughs is made with 6 pounds of rosin, 1 pound of red ochre 1/2 of a pound of plaster of Paris, and 1/4 of a a pound of linseed oil. The ochre and the plaster of Paris should be calcined beforehand, aud added to the other ingredients in their melted state. The thinner stratum of cement that is interposed, the stronger, generally speaking, is the junction.