I just posted this in another forum and am copying it to prevent my arthritus in my fingers from kicking in (not to mention my lack of typing skills!!), but I think its germain to the subject:
A "touch-up" gravity feed HVLP of reasonable quality will only run about $50, and will run off a small compressor. The advantage of the Touch-up size is that it is more maneuverable for spraying inside areas and can be adjusted to a finer spray pattern. (Don't confuse Touch-up gun with air brush, they are not the same).
There are a lot of safety considerations to spraying. Atomizing a flammable substance greatly increases the potential for disaster. Pilot lights on water heaters,etc, the spark from a freezer in the garage, etc all may cause a bad end to everyone's in the neighborhood day. Although ventilation is a must, the commom electrical fan with open brushes on the motor will provide a very lively ignition source. Even some of the "water clean-up" coatings have alcohol (flammable) based solvents. (Check the label on the can) The overspray build-up also can be very flammable.
And even of they aren't flammable, coating fumes can cause both short and long term damage to your internal organs. The first prerequisite is an organic vapor respirator (a dusk mask won't protect you from the fumes). The filter should have NIOSH marked on it and say it protects from OV. Also, realize the blood vessels in your eyes will absorb 10 times more toxic substances than your skin, so the more you can keep the paint particles way from your eyes (safety goggles help because full-face respirators are pretty expensive!) the better off you will be.
I'm not trying to sound preachy, but I've been spraying coatings for over 30 years, and I personally won't crank up a spray gun in my garage or any other room attached to my home. I don't consider the benefits worth the risk to my family's safety. If you spray outside or in a detached workshop, please be careful. And practice on scrap first, until you get the trigger discipline down (start spray gun moving, depress trigger, spray while continuing steady movement and holding gun perpendicular to the surface, let up on trigger, stop spray gun movement). It will result in a lot less runs and better coverage. You can practice with a spray can to get the basic feel for it.
Good luck
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