A fair bit of stuff. Off the top of my head:
- Sandblasting cabinet and a big enough compressor to run it.
- Acetone soak tanks
- HVLP gun - Iwata LPH-80 is the go to, but I started with a cheapy which was serviceable enough short term.
- Oven for baking. I have a big oven for rifles and chassis, and a smaller one set up for pistols and accessories.
- All the various beakers and syringes for mixing etc. Gloves, strainers.
- Good respirator - stuff is pretty nasty.
I think thats about the barebones to get you going? Obviously air dryers etc for spraying are recommended, but it all adds up quickly.