Your major purchase, and the first to consider, is an air compressor ?
Simply put, get the best you can afford. The “standard” for home painting are Sears Craftsman portable models, and the hot tip is to buy one when they are on sale. From personal experience, I would strongly recommend a 220-volt unit of at least 1 horsepower (preferably 2 hp).If you garage doesn’t have a 220-V outlet, having one wired in can be a minor problem; but having a 110-V compressor blow a circuit (invariably including garage lights) in the middle of a paint job is a much worse problem . . . especially when it happens repeatedly.
How much compressor do you need?
Specifically, it must deliver enough volume at a given pressure (listed as “SCFM”: standard cubic feet per minute) to operate the paint gun or other tools you intend to use with it. Spray guns and all air tools have an SCFM-requirement rating, usually given at 40 psi, at 90 psi, or both. A good spray gun usually requires about 6 to 8 SCFM at 40 psi, but air sanders can require 6 to 8 SCFM at 90 psi. Our recommendation: get a good compressor which will operate air tools you may buy in the future.
- With your compressor, you obviously need a hose long enough to pain all the way around a car. A 25-foot one will probably do it, and a 3/8-inch i.d. will minimize pressure drop. Secondly, you need at least one good water trap in the air line, because water condenses out of compressed air. Preferably put one large water separator at the outlet of the air tank, and a second, smaller one near the spray gun. If you have just one water trap, place it 25 feet from the compressor.
- Remember that whatever comes out of your compressor gets sprayed onto your car. Drain the air tank regularly, make sure the compressor is drawing in clean air, and–if the compressor is old–make sure it isn’t blowing oil past the rings. Any oil in the air tank or hose can ruin a paint job (causing “fisheyes”); never use an air-tool oil-mister on a compressor that will be used for painting. Never use a hose that has had oil in it.
- Most compressors these days have a built-in pressure regulator and gauge. If not, you must add one at the compressor outlet. However, since pressure drops in the hose (as much as 10 psi in 25 feet), most painters use a small regulator valve at the spray gun, and adjust it by “feel” for proper spray pattern. If you want to go by the book, similar adjusters are available with a built-in pressure gauge. And to make everything a whole lot simpler when using your compressor, get an assortment of quick-connect couplers for the hose, spray gun, blow gun, tire filler, and any air tools you may buy. For the price, you’re nuts not to use them.
TOOL AND ACCESSORIES
- With proper cleaning, oiling, and repacking of seals, a good spray gun should last at least one lifetime. Mine’s probably lasted a couple (somebody gave it to me over a decade ago, and it was well used then). The message here is simple: get a good spray gun, and take good care of it. Instructions with a new gun will show how to clean and oil it. A siphon-feed gun with a 1-guart pot is all you need for car painting; a good gun should have a quick-release cup (a screw-on cup is a real bother); and the only “extra” worth considering is a dripless vent of some sort. One drip from your spray gun can ruin a paint job; however, a vent that clogs with paint can also be a hassle (paint won’t siphon out of the cup if the vent clogs).
- Some painters like to keep an extra gun on hand to spray primer. That’s fine if you happen to have an extra gun (maybe a cheap one came free with your compressor). But you certainly don’t need a primer gun–you never spray primer and finish coats in the same day anyway. A more useful tool would be a touch-up gun, though this is still a minor extravagance. The touch-up gun is excellent for painting door jambs, dashboards, window frames, body stripes, or doing what its name implies.
What the well-dressed garage painter wears is up to you, but one thing you need is a good respirator. Never–repeat–NEVER paint a catalyzed acrylic enamel or urethane type of paint without one. The label on the paint can will tell you what type of maks and filters you need, and your paint store can supply them. Primers, lacquer, and straight enamels aren’t nearly as toxic, but still wear a mask when spraying them. The small, throw-away “doctor’s masks” are great for keeping Bondo dust out of your lungs when you’re doing bodywork, but use a respirator when you’re painting.
WHERE TO DO IT ?
- If you’re using lacquer (which dries very quickly and which you will color-sand and rub out afterwards), you can paint a car in your driveway, but I certainly don’t advise it. Assuming you have a garage, and it isn’t crammed full of junk, that’s the logical place to paint (if it is crammed full of junk, clean it out). The two primary considerations are that it be well lit and well ventilated. An exhaust fan would be nice. Don’t paint with the door shut (to keep out dust, bugs, etc., you can prop the door open a couple of feet; in fact you could prop it with a house fan, blowing out, not in). For lighting, it’s imperative to be able to see what you’re doing on all sides of the car. Overhead lights in the middle of the ceiling won’t do. If you don’t have light on both sides of the garage, rig up some temporary ones before you start to paint.
- Secondary considerations: You need a god electrical circuit for your compressor, preferably separate from the light circuit (better yet, as we said, 220-volt). Place the compressor where it can get cool, fresh air. Sweep the floor, or hose it down. And if you want to keep overspray off things in the garage, you can hang plastic sheeting over them. Lacquer overspray is a minor problem; it’ll blow off (or sweep up) like dust. Enamel overspray, however, gets on everything.
- What if you don’t have a garage? There are several options. You could actually build a spray booth out of 2×4’s and plastic sheeting (as shown). In fact, one company (U.S. Systems, P.O. Box 1628, New Rochelle, NY 10802, 800-US-CLAMP) makes pre-fab or do-it-yourself portable spray booths featuring 3/4-inch conduit tube frames and rip-stop polyethylene covering, ranging in price from $350 to $900. Better yet, in many urban areas you can find professional-style spray booths ot rent on a half-day or full-day basis. Look in the Yellow Pages, or ask at the local automotive paint store to find one. A rental booth might be an excellent way to try your first paint job, since you don’t even need your own compressor–just a spray gun. Even if you paint in your garage, a rental booth is preferable for enamel or catalyzed paint jobs. The only drawback is figuring out how to get the prepped (stripped) vehicle there, and get it back in a coat of fresh paint.
The final consideration–and it can be serious–is for your neighbors. The city I used to live in had a law specifically forbidding the painting of a car in a residential garage. You could paint a table, bicycle, or boat, but not a car. I wasn’t aware of the ordinance until a neighbor complained, and both the police and fire department showed up. I moved. Know the local regulations. Don’t abuse neighbors’ rights. This is another reason we suggest using low-toxicity paints, such as lacquers. Plus, offering to touch up scrapes and dents on neighbors’ cars can do wonders for community relations. Just a suggestion.
That’s plenty for now. Next month we’ll let you get your hands dirty–real dirty–as we discuss paint stripping and how far to disassemble your car for its new coat.