How to Spray Paint Clean
by Damien Andrews
Despite the trend towards using plastics to replace traditionally metal parts, spray painting has never been so popular. I don't have any statistics available to support my conclusion, but based on the availability of spray paint at the hardware stores, I'm pretty confident in my statement. I'm not talking about the kind of spray painting that requires a pricey spray gun and a compressor capable of putting out 7 CFM @ 90 PSI. I'm referring to the sort of spray painting one does with a can of prepared product. And while you can get spray paint in a can for any conceivable application, this missive deals with the spray painting of metals.
Before I go any further, if you have not visited the spray paint section of your favorite hardware stores lately, I would invite you to do so. While the advances made in the technology of spray paints might not be readily apparent from looking over the sea of cans, the endless colors and varieties of paint will indeed impress you. There is even spray paint primer for rusted metal parts that allows you to skip the step of removing the rust – just spray paint right over the corrosion with the primer, then apply your finish coat. I am also impressed with the varieties of spray paint which allow me to apply second and third coats within 15-minutes – sure cuts down on the job time!
Spray painting things will, as is obvious, improve their appearance. But in many cases items should be spray painted so that they will give a longer period of better service. Remember, once rust begins, it only gets worse. There's a phenomenon that occurs with rust. It's called "rust smacking." It's when parts are pushed or pulled apart by rust. It is caused by the fact that rust has a greater volume of mass than the host metal. In the instance of a nut and bolt, the rust on the two pieces pushes them further apart, weakening the nut's hold on the threads of the bolt – which may also be rusting.
Fortunately, most things that are around the do-it-yourselfer's house that need some spray painting are relatively small. A short list of candidates includes: gate latches; exterior hinges; flag standards; barbecue grill parts; yard tool components (lawn mower/tiller air cleaner covers, shovel heads, hoe heads); and trailer hitch components.
Perhaps the greatest nemesis of the do-it-yourself spray painter is overspray. Overspray is, essentially, all the paint that was sprayed, but did not land on the object being painted. As any experienced spray painter will tell you, overspray has the ability to travel great distances from where the spray painting occurs – and it always sticks to the things you least want it to stick to. Fortunately, it doesn't bond securely to what it lands on and is rather easily removed. Still, preventing overspray from being able to fly everywhere in the painting area – sticking to whatever is wishes – is the better option. In an open area, such as a garage, even with no moving air, overspray can travel 10 feet or more from the work. And since you are supposed to spray paint in a well ventilated area (for safety reasons), there will likely be at least some air motion where you do your spraying.
There's an easy, cheap way to confine overspray: a cardboard box. Just go to your local supermarket's trash container and scrounge around until you find a box that is properly sized for your spray painting project. Don't select a box that the item you're spray painting just barely fits into. Remember, you're going to have to get your hand(s) and the can of spray paint into the box. I like boxes that are about two feet square for almost all small parts spray painting.
If your box was collapsed, tape one end of the box closed. Lay your spray painting box on its side and open up the flaps on the open end of the box. Lightly tape the loose, open flaps into a fully open position, thus increasing the size of your spray painting box. If you'll be using this box for several projects or repeated sprayings, then do a better taping job so the box is more stable. Now slide a couple of pieces of old newspaper under the open end of the box to catch any overspray that escapes the trap. Be sure to put some newspaper under the seams of the flaps you taped, and extend it outside the box about two feet.
NOTES: • Use disposable rubber gloves for the hand holding the object to be painted. • Be sure to completely shake the can of spray paint before using it. • Use several light coats to prevent drips and get a smooth, even finish. • When you're through spraying each time, turn the can upside down and depress the spray button for 3-5 seconds to clear the paint out of the nozzle. This step ensures trouble free spraying the next time you want to use that can of spray paint.