A clean booth is a happy booth. Scrape the overspray from your walls and floor on a regular basis. Consider using a peelable booth spray or a non-flammable booth paper to make the job easier. Change your filters as necessary. Most booths have a manometer that will indicate when the flow of air through the booth falls to an unacceptable level due to dirty filters.
Most importantly, don’t forget to clean the stack. If you change your filters regularly, you should not have too much buildup. Some home improvement stores have extendable chimney sweeping brushes that simplify this task; just watch out for any sprinkler heads that may be in the stack. Since you can’t have the booth running while you do this, be sure to wear a good quality dust mask and goggles. While you are at it, check the fan blades. Even a small accumulation will decrease your draw and raise noise levels. Make sure the power is locked off when working anywhere near the fan.
Dried paint residue on a booth’s walls and floor can fuel a booth fire rather easily. Even worse, dried paint residue can spontaneously combust. It doesn’t take a spark or an external heat source to ignite. This phenomenon is called composting. This is especially true if the residue is made up of layers of different types of paint. The layers of paint can generate heat, much like a pile of cut grass can. Unfortunately, they get much hotter than a pile of grass. The other bad point is that if you have enough overspray on your booth to spontaneously combust, then you have enough fuel for a pretty big fire. Once the fire gets in the stack it becomes very difficult to put out. Considering that most spray rooms have flammable solvents and finishes stored in them, this only adds fuel to the fire (no pun intended). One other point, overspray from waterborne finishes is also flammable, so don’t be lulled into complacency just because the product is not flammable in the can.
When performing the maintenance on the booth, do not forget the guns and other items used in the booth. Clean them and fix them before you start the next job rather than having to stop in the middle of it.