Yoshihiro Hisamatsu

Tests for Average Tickness of Zinc Coating

Three methods of testing the average thickness of Zinc coating on iron wire, i. e. HCl-SbCl3 metlhod, Eiectrolytic method, & Gas-evolution method were compared. Samples used were, No. 1-hot dipped at 480°C, No. 2-at 600°C, No. 3-at 450°C without wiper, No. 4-at 450°C, and No. 6. 7. 8- electroplated ones.Results obtained:1) As the electrolyte for the electrolytic method, Brittons solution containing NaCl was found to be better than 1N-ZnSO4 solution.2) In the gas-evolution test, dil.-H2SO4 (5% for hot-dipped, 10% for electroplated) must not conain arsenious oxide.3) The electrolytic method gave smaller values than those of HCl-SbCl3 method, and the gas-evolution method gave greater values.