hi bob
        the parafin wax dippingtank i use is approx 4' by 3' by 3' it has a
fire box underneath with a flue comming up thru the middle terminating about
a foot above the tank. the tank is about two thirds full of wax i light a
fire underneath to heat the wax .
when dipping new and non infected gear  i heat the wax to approx 120 degrees
centigade and dip for 5 minuets ( AFB gear needs 160 degrees for at least 10
mins, i give it 20 ). i wear heavy gloves and use one of those slideing
adjustable pipe wrench thingys to grab and lift the gear out of the hot wax.
some paints will bubble just scrape off while still hot and repaint. as for
paint and crud in the wax melter a bit of mesh folded up and nailed to a
length of batten can be used to scrape the bottom of the melter
periodically.
 as for a build up of wax on excluders the wax is too hot to set immediately
so it drains off quite readily a bump on your pile of fire wood as you
remove your excluders also nocks off any debris that may still be clinging
to you excluder.
    one of the first commercial beekeepers I worked for used a 44 gallon
drum over a fire pit as a dipping drum.

Sincerely,
    shaun cranfield