CEMENT AND CONCRETE PAINT TESTS 217 



This panel, after three years' exposure, is in good condition. 

 Slight checking observed. 



Test No. 2. Concrete primed with a 20% solution of (alum) 

 (aluminum sulphate). Second and third coated with No. 119 

 blue. 



In similar condition to Test No. 1. 



Test No. 3. Concrete primed with zinc sulphate followed by 

 two coats of para red. 



PARA RED FORMULA 



Blanc fixe . 60% 



Whiting 25% 



Zinc oxide 3% 



Paranitraniline lake 12% 



Ground in linseed oil, turpentine and drier. 



Panel in fair condition with exception of slight crazing. Char- 

 acteristic dullness of color after exposure shown. Bright red 

 color restored upon washing. 



Test No. 4. Concrete primed with an 8% solution of stearic 

 acid and rosin dissolved in benzine. Second and third coated 

 with No. 119 blue. 



This panel is not in as good condition as Tests Nos. 1 and 2, 

 and would indicate the inferiority of the priming liquid used. 

 Color failing in spots and checking observed. 



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 condi- 

 tion. 



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. 



