Oh boy, without bragging, I think am the expert on this very thing. I bought a used paint booth, and old Binks crossflow. So I trundle down to my local building official to get a building permit. This is where the fun began. What I am sure you will find out, the stumbling blocks are automated fire suppression and vendor literature.

Starting with the fire protection, it doesn't matter if your jurisdiction uses the IFC (International Fire Code) or references NFPA 33 which covers spray booths....all of them require automated fire suppression. The approach I took was to claim that all of these requirements are for commercial spray booths, not hobbyist, and as such did not apply. I pulled out the "hobbyist exemption" that the EPA has as support. That exemption is:

"EPA “40 CFR Part 63 National Emission Standards for Hazardous Air Pollutants: Paint Stripping and Miscellaneous Surface Coating Operations at Area Sources; Final Rule” defines a specific exclusion for paint booths used strictly for hobby purposes. Specifically the language of that exclusion is (3) in the following excerpt from that standard.

“…. (3) Surface coating or paint stripping performed by individuals on their personal vehicles, possessions, or property, either as a hobby or for maintenance of their personal vehicles, possessions, or property. This subpart also does not apply when these operations are performed by individuals for others without compensation. An individual who spray applies surface coating of more than two motor vehicles or pieces of mobile equipment per year is subject to the requirements in this subpart that pertain to motor vehicle and mobile equipment surface coating regardless of whether compensation is received. …”

I came at them with this argument and initially it didn't make any difference, they denied the permit claiming that it still applied and claimed my insurer would not insure it. So I got a letter from my insurance company that said they didn't care and went at it again. This time I was successful. I do not have the permit in hand but I was told that as part of the permit, I will be held strictly to the requirements of the EPA exemption, no cars (or equivalent parts) that I don't personally own, only I can use the booth, and no more that two cars (or equivalent parts) annually. The rest of the IFC requirements as to ventilation stacks, interior booth ventilation requirements, and interior setbacks still apply. I also have to have two ABC fire extinguishers in the booth at all times (they still haven't decided how large they need to be).

If this had not gone my way this is what I was prepared to do:

1) If they would have held me to the IFC, the IFC has an exemption for flash point liquids (basically waterborne paints) and I would have claimed that.
2) If they would have held me to NFPA 33, it has an exemption for no more than a quart of paint daily and I would have claimed that.

Now to the vendor information, if you can't find vendor information for the booth, you already at a big disadvantage. I am sure you will be fielding questions like "How big is it?", "What is the airflow of the fan"?, "What is the velocity in the booth"?, or other questions only the vendor literature covers. I was lucky enough that one of the old Binks district offices still had both the assembly instructions and the booth data sheet in their files.

I am going to assemble mine just for the convenience. Want to spray a K-mamber? Light up the booth and do it. A steering column? A rear end? A set of springs? And on and on. So, in a nutsell:

1) Talk to your building official about the need for vendor information
2) Talk to your building official about the need for automated fire protection. If your nephew won't let the dry chemical suppression system go with the booth, that is a minimum of $8K to install it.
3) Do both of these BEFORE you invest any more time and effort.

That's my experience with this. And frankly, going in I thought the biggest problem was going to be how to unload it off the trailer!!