Test No. 5. Concrete primed with mixture used in Test No. 4, and then given two coats of para red.
Test is in about the same condition as No. 4.
Test No. 6. Concrete primed with a 10% mixture of acid calcium phosphate, followed with two coats of No. 119 blue.
The acid phosphate solution evidently had a neutralizing effect upon the lime in the concrete, as the paint is in fair condition.
Test No. 7. Concrete primed with one coat of a soap emulsion of the following composition, then painted with two coats of No. 119 blue.
| Water | 85% |
| Linseed oil | 12% |
| Alkali | 3% |
Very poor results obtained. Destruction of color and peeling resulted.
Test No. 8. Concrete primed with one coat of white paint of the following composition:
Primer
| Zinc oxide | 25% |
| Silica | 35% |
| Corroded white lead | 20% |
| Gypsum | 15% |
| Whiting, etc. | 5% |
| Ground in a vehicle of linseed oil and containing 35% of volatile hydrocarbonspirits and drier. | |