My recipe as far as acids go is a fairly mild acid bath.. Metal prep would be the same as if you were using evaporust which also has a low enough ph to be considered a acid and produce the hydrogen smell you smell on the metal parts when you remove it from both solutions.. The ph in normal tap water is actually high enough in my area to neutralize the acid on its own but adding baking soda will raise the ph and neutralize the acid . A bucket of soapy water "I like to use a little dawn dish water soap" and add some baking soda in.. 1 cup in a 5 gallon bucket will spike the ph out! .. no need to go overboard! Solutions with a pH less than 7 are said to be acidic! both my home-brew mixture and evaporust fall into the acidic category "even though evaporust claims to not use acids their material data sheets claim otherwise" Both products work great! Both require prep after a bath & before painting! I would treat them both the same and use evaporust if your working on old wristwatch mechanical internals/delicate stuff. My mix will work just fine for our mopars!!! & save you some cash!!!