Homemade powder coating cabinet made by XLFORUM member simeli:
Using 5000 watts of heater element it reaches 450° in 15 minutes.

I allowed it to stay hot for 45 minutes before shutting it down 2 hours later it was still 180 degrees inside the box.

• 108 sq. ft. of insulation
• 20 gauge steel for the heat box faced with cement board
• 4 inches of space packed with 70 sq.ft. of insulation
• The door face is 20 gauge steel (as is the surroundings) with 1-1/2“ of space with 30 sq.ft. of insulation packed into it.
• 1/4” gasket on the surroundings.

Door latches were not installed in the pics below but jack straps were used in their absence.
Total cost: about $497 (not counting the door latches)

Homemade powder coating cabinet. 1)