Making a DIY Powdercoat Curing Oven Using Free Kitchen Oven Parts, Saving Thousands of Dollars

I had been waiting for a free oven to come up close to me, and I finally snagged one. The only problem, they're too small for the parts I want to powder coat.
Any specialty equipment is really expensive. If someone can make something - someone totally not set up for making ovens in an efficient way, for way less money, they're overpriced.

Interior is 2'x2'x4' - Big enough for bike frames, wheels, and other mid sized parts.