160 



The Philippine Journal of Science 



1916 



Table VI. — Tests on various brands of galvanized iron by the hydrochloric 



acid methods 



Brand 



No. 



Total 



loss in 



weight. 



(a) 



Iron dis- 

 solved 

 with 

 zinc, 

 (b) 



b/a. 



Iron dis- 

 solved 

 from 



stripped 

 sheet. 



Total 

 loss per 

 square 



foot. 



Iron in 

 coating 



per 

 square 



foot. 



Iron dis- 

 solved 

 from strip- 

 ped sheet 

 per square 

 foot.t 



Initial 

 temper- 

 ature. 



Final 

 temper- 

 ature. 



°C. 



45 

 45 

 40 

 40 

 40 

 42 

 38 

 40 

 41 

 43 



li>.._- 



2 



3 



4 



8 



Grams. 

 1 18. 179 

 1 18. 939 

 1 17.790 

 1 18.880 

 20. 571 

 1 17.680 

 1 11. 259 

 I 13.170 

 1 18.026 

 1 20.356 



Grams. 

 0.7826 

 0. 8036 

 0. 8050 

 0.8638 

 0. 6210 

 0. 4724 

 0. 5012 

 0. 5670 

 0.6608 

 0. 7350 



Per cent. 

 4.29 

 4.26 

 4.53 

 4.57 

 3.02 

 2.67 

 4.54 

 4.30 

 3.63 

 3.61 



Grarns. 

 0.035 

 0.034 

 0.035 

 0.020 

 0.043 

 0.030 

 0.036 

 0.030 

 0.059 

 0.089 



Ounces. 

 2.56 

 2.67 

 2.51 

 2.66 

 2,90 

 2.49 

 1.58 

 1.86 

 2.54 

 2.87 



Ounces. 

 0.11 

 0.11 

 0.11 

 0.12 

 0.09 

 0.07 

 0.07 

 0.08 

 0.09 

 0.10 



Ounces. 

 0.005 

 0.005 

 0.005 

 0.003 

 0.006 

 0.004 

 0.005 

 0.004 

 0.008 

 0.013 



°C. 

 31 

 80 

 29 

 29 

 29 

 29 

 29 

 29 

 30 

 30 



a Density of the acid, 1.098. 



•> Brand used in all previous tests. 



■^ At end of twenty minutes. The stripped sheets were placed in acid of the same density, 

 at 30°. In this case the action was so slight that there was no appreciable rise in temperature. 

 Each sample was 15.25 by 15.25 centimeters. 



A study of Table VI reveals the following: 



BETWEEN TWO SAMPLES OF THE SAME BRAND. 





Grams 

 per 900 

 square 

 centi- 

 meters. 



Ounces 



per 



square 



foot. 



Brand 

 No. 



Minimum difference in coating. . _„ .. 



2. 9397 

 0. 5944 

 0. 1418 



0.11 

 0.02 

 0.005 



1 

 3 

 5 



Maximum difference in alloyed iron . _ 



Maximum difference in iron dissolved from stripped sheets 



BETWEEN TWO SAMPLES OF DIFFERENT BRANDS. 



Grams 

 per 900 

 square 

 centi- 

 meters. 



Ounce 



per 



square 



foot. 



Brand 



No. 



Maximum difference in coating 



Maximum difference in alloyed iron 



Maximum difference in iron dissolved from stripped sheet 



37.2480 

 1. 5256 

 0.2835 



1.32 

 0.05 

 0.01 



3.4 

 2,3 

 2.6 



* In all brands tested, except No. 5. this difference is negligible when temperature, con- 

 centration of acid, and time are uniform. 



THE REACTION BETWEEN HYDROCHLORIC ACID AND GALVA- 

 NIZED IRON 



These measurements were made with the object of obtaining 

 a clearer idea of just what happens when a galvanized sheet 



