When I use milk stone remover, I use the amount on the label. I mix it with water and then heat it to just barely over what I can hold my hand into. Then I let it set about 30 minutes, brushing lightly each few minutes. Be sure to wash your hands well if you test by sticking your finger in the hot solution, I use a neoprene glove.
If I have a bad burn, I alternate between milkstone remover and white vinegar, but most often it is good with just the first application.
Dave Klish, I recently bought a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.