Where do you buy H3P04 in technical grade? - GWE

DanD wrote:

"R. O'Brian" wrote:


The Metals Handbook, Vol 2,"Heat Treating, Cleaning and Finishing", 8th
edition gives a couple of recipes:

#1 sulphuric acid 41%
phosphoric acid 45%
water 14%
operating temp: 170-230F
current density: 200-350 A/sq.ft.

#2 phosphoric acid 56%
chromic acid 12 %
water 32%
operating temp: 80-175F
current density 100-1000 A/sq.ft.

All percentages by weight. You might want to get a copy of the book. It
contains articles on electropolishing and every other finishing method you
could want. Copies are available on the used book sites

Randy


Thanks Ron and Randy for the helpful info. I think I will try changing
my electrolyte to the H2SO4 - H3PO4 mix at elevated temps as suggested
by the Metals Handbook. Hopefully it will do the trick. Will report
back on my results.

Kind regards,
Dan