By Roy Smalley
For those who consider painting their cars themselves, and doing it in a sealed up garage instead of a paint booth to save the cost of renting a booth, think again. The advantage of a spray booth is not entirely about quality; it is also about safety.
Standing around in a fog of carcinogens and fumes that might spontaneously ignite if they reach the ignition threshold of that plug in the garage wall, or when that compressor kicks on should be more of a consideration than dollars.
An old saying comes to mind.....don't let your reach exceed your grasp.
Some things to think about...
Why are booth electrical components external to the booth? And the one or two necessary in the booth and in the proximity of external openings explosion proof, even though there is ample air flow to exhaust fumes? Why, is the compressed air supply coupled with an electrical cut off switch if a booth door is opened? Why are booths normally supplied with either chemical or water type fire extinguishers when the larger facility containing the booth may not? Are most paint components highly toxic? What are the ways your body can take in toxic chemicals? What are safe levels of exposure?
Restoring a car or several involves real risk from several sources for the unwary. That old undercoating you are scraping off for instance. Ever checked to see what that was? That lead based paint (oops) you are grinding or sanding off the car. Oh, and that parts cleaner you are breathing and getting all over your hands and arms.
I understand completely the individual need, and encourage anyone restoring a vehicle to do as much as they can. Each has to make their own decision regarding the level of risk for painting, leading, dry blocking plastic, dry blocking primer, welding, etc. Read the literature about all the systems. Not just the labels. Get the MSD sheets. Google the ingredients...and then decide. You make your own choice based on your judgment.
Regarding modern paints...
Most paints these days are designed for the air flow characteristics of a downdraft booth which has a great deal of air flow, and for the most part the air travels quickly and down to the exit filters, rather than stagnate and drop on the surface. Economical production in a collision shop and booth utilization depends upon clean jobs.
There are some paints remaining that can be sprayed in a cross draft booth which has less air flow, and solvent pop should not be a problem. And in carefully chosen environments, can be sprayed without a booth.
If there is not adequate flow of air as in a down draft booth, the airborne solvents fall back onto a painted surface creating minute craters in the finish coat. If you have a high ambient temperature and quick acting solvents, that is minimized. If cold and slow dry, it can be a real problem.
When purchasing finish coats, ask if the formulation can be used in low air flow environments, and stick to the directions regarding application temperature and cure time of the hardeners and reducers.
Roy Smalley is the proprietor of Eurowerks Incorporated