[Tom Goldman]

Coleydog got it with the Red Devil lye ….cheap and effective.
I've been using it for years since machine shops have been getting rid of their old caustic hot tanks.
I use a large heavy duty 23 gallon storage tub with a bung installed on the side with an old oil pan heater element I had laying around in it .
I try to keep the temp around 175-80 and I have a tube thru the cover that I can hook up to the air hose to aerate the mix and keep it cleaning.
What ever you use for a container, if it's plastic make sure it will crush and deform , not crack .