Mixed to form a stiff paste, sets and becomes very hard and strong, and is very useful for inserting glass tubes, etc., in iron or brass.
For a high heat:
| 2. | Alumina | 1 part |
|---|---|---|
| Sand | 4 parts | |
| Slaked lime | 1 part | |
| Borax | 1/2 part | |
| Water sufficient. | ||
A class of mixtures that can be classified only according to their intended use are core compounds.
| I.— | Dextrine, about | 1 part |
|---|---|---|
| Sand, about | 10 parts | |
| With enough water to form a paste. | ||
II.—Powdered anthracite coal, with molasses to form a stiff paste.
| III.— | Rosin, partly saponified by soda lye | 1 part |
|---|---|---|
| Flour | 2 parts | |
| Sand (with sufficient water) | 4 parts |
(These proportions are approximate and the amount of sand can be increased for some purposes.)
| IV.— | Glue, powdered | 1 part |
|---|---|---|
| Flour | 4 parts | |
| Sand (with sufficient water) | 6 parts |
For some purposes the following mixture is used. It does not seem to be a gasket or a core compound: