| II.— | Glue | 6 ounces |
|---|---|---|
| Alum | 30 grains | |
| Acetic acid | 1/2 ounce | |
| Alcohol | 1 1/2 ounces | |
| Water | 6 1/2 ounces |
Mix all but the alcohol, digest on a water bath till the glue is dissolved, allow to cool and add the alcohol.
| III.— | Glue | 5 ounces |
|---|---|---|
| Water | 1 ounce | |
| Calcium chloride | 1 ounce |
Dissolve the calcium chloride in the water, add the glue, macerate until it is thoroughly softened, and then apply heat until completely dissolved.
IV.—Glue, 1 pound; glycerine, 4 ounces; glucose syrup, 2 tablespoonfuls; tannin, 1/10 ounce. Use warm, and give an hour to dry and set on the pads. This can be colored with any aniline dye.
Marine Glue.
I.—One part Pará caoutchouc is dissolved in 12 parts benzol; 20 parts powdered shellac are added to the solution, and the mixture is carefully heated.
II.—Stronger glue is obtained by dissolving 10 parts good crude caoutchouc in 120 parts benzine or naphtha which solution is poured slowly and in a fine stream into 20 parts asphaltum melted in a kettle, stirring constantly and heating. Pour the finished glue, after the solvent has almost evaporated and the mass has become quite uniform, into flat molds, in which it solidifies into very hard tablets of dark brown or black color. For use, these glue tablets are first soaked in boiling water and then heated over a free flame until the marine glue has become thinly liquid. The pieces to be glued are also warmed and a very durable union is obtained.
III.—Cut caoutchouc into small pieces and dissolve in coal naphtha by heat and agitation. Add to this solution powdered shellac, and heat the whole, constantly stirring until combination takes place, then pour it on metal plates to form sheets. When used it must be heated to 248° F., and applied with a brush.