Electrolytic Mill Scale Removal

[RJSakowski]

When I create a pickling solution, I add water until I can no longer see fumes rising. Even a diluted solution like this is still strong enough to reduce the scale to sludge in less than 30 minutes. At most, you should see almost complete removal in less than an hour (the temperature may have an effect on the speed of removal - where I live 85º to 90º is the norm). YMMV

I basically use the same dilution method, mostly for my convenience. The label on my Sunnyside Muriatic Acid state 31.45%. And reaction rates are very definitely influenced by temperature. A rule of thumb is the reaction rate doubles for every 10ºC increase.

 

[Dabbler]

Try citric acid. I prefer citric over vinegar.

Citric acid and Oxalic acid are chelating agents and work differently than strong acids. No need to neutralize them, a risnse is recommended, then dry.

Strong acids can and will etch the underlying metal with time. I have left steel in citric acid (my preferred) for a month, and the rust/scale is gone, but no pitting of the surface, except for the end that was rusted (orange) that was removed by the citric.

I can easily forget my scale removal as I usually have 10 projects on at once, so having the confidence of being safe appeals to me.