You're probably thinking to yourself, a tech article on spray painting? You've got to be kidding. But seriously, I have had so many people ask me how I am able to get such a nice finish on my parts with mere spray paint, that I thought I would write an article on it. Spray paint has come a long way over the past couple of decades. It's wonderful because it requires no tools, it's very durable, easily reparable, and best of all- it's cheap. When applied properly, spray paint can look every bit as good as powder coating, and for a fraction of the cost. It's a great tool to help keep your project build costs low. So, how do you spray paint like a pro? Here it is: 1.) Preparation: Arguably the most important step. If you want your parts to look really slick, then you have to be willing to put the time in up front for proper preparation. The first thing to do is clean the parts of all the old paint, grease, debris, gunk, etc. Small to medium size parts can be cleaned with wire brushes, steel wool, sandpaper, etc. Be careful not to excessively gouge the metal with overly rough abrasives while cleaning. Clean bare metal surfaces should appear a swirled dull silver which is is smooth to the touch. For medium to large size parts, media blasting is wonderful. Note I say media blasting and not sand blasting. Sand as a blasting agent is too fine, and will become embedded in the metal, no matter how much you clean the surface. This can be disastrous down the road, as the sand can later rise to the surface under the paint, causing it to dimple, crack, peak, and feel rough. Media blasting refers to the use of different blast agents, or "media" (e.g. copper slag, gl*** beads, etc) to blast a metal surface clean. These alternate types of media are too large to become embedded in the metal surface, and can be completely cleaned off after blasting is complete. Media blasted parts will appear matte silver after blasting (click on thumbnails for larger image). '59 Ford frame before media blasting. Nasty, rusty, greasy...just ick. '59 Ford frame after being media blasted with copper slag. Clean! 2.) Cleaning the prepared parts: Now that you are just about ready to paint, you need to make sure that your prepared parts of completely clean. Metal surfaces that have been cleaned with abrasives should be blown with compressed air to clean off all macro debris. You can use Xyelene, brake cleaner, or orange oil to clean off any remaining grease. Let the cleaning agents completely evaporate before painting. For media blasted parts, use compressed air to blow off any macro debris. Use a stiff bristle brush and brush the surface of the parts throughly. Do not use any type of liquid cleaners on media blasted parts. After brushing the parts, blow the parts off again with compressed air. Repeat this process until no debris blows off the blasted parts. 3.) Painting: You will need spray paint primer and the finish color of your choice. I have had very good results with Rustoleum Professional spray paint primers, and and finish colors. I have also had good success with Krylon. Dupli-Color and I don't get along. For ideal results, it is best to paint in a dry, warm (60-80 degrees F), still air environment. If you are able to, hang your parts. This will allow you to paint all sides at once for the best consistency. Be sure that you select a painting location where the over spray will not affect anything. Primer Coat: Shake the primer spray can vigorously to ensure proper mixing. Don't be lazy- spend about 2 minutes shaking the can, making sure the mixing ball is really clacking around in the can. Spray a couple of test sprays on a s**** piece to get the nozzle primed. The painting goal to keep in mind here is thin coats. Hold the can about 18" inches from the surface. Spray the surface in short bursts, thus "dusting" the surface. The first "dusted" coat should be somewhat translucent. Do not try to completely coat the surface on the first p***. Wait about 5 minutes and spray a second coat. Use the same technique as before, but spray in slightly longer bursts. This coat should be mostly opaque. Wait about 10 minutes and spray a third coat. Same technique, but again with longer bursts. This coat should be completely opaque. This wet on wet spray technique helps all the thin coats to bond with one another. '59 Ford frame with first grey primer coat. Notice the patchy "dusting" effect '59 Ford frame with second primer coat Finish Coat: Wait about one hour after spraying the final primer coat. Once again, the painting goal to keep in mind here is thin coats. Hold the can about 18" inches from the surface. Spray the surface in short bursts, thus "dusting" the surface. The first "dusted" coat should be somewhat translucent. Do not try to completely coat the surface on the first p***. Wait about 10 minutes and spray a second coat. Use the same technique as before, but spray in slightly longer bursts. This coat should be mostly opaque. Wait about 20 minutes and spray a third coat. Same technique, but again with longer bursts. A properly sprayed third coat should look consistently "wet", with no paint stipples, and should be completely opaque. This wet on wet spray technique helps all the thin coats to bond with one another. '59 Ford frame with first finish coat of satin black. Notice the patchy "dusting" effect '59 Ford frame with third and final finish coat of satin black 4.) Drying: The easiest part as far as labor goes, but maybe the hardest step to comply with. Now that you have done such an excellent paint job, you should want it to last. Most spray paints will state that they will dry in 2-4 hours. This is true, but only on the surface. If you want your paint job to really be durable, let the parts sit for a week. That's right- a week, 7 days. This will let all those spray coats fully bond and dry, and is allows the paint to achieve its maximum durability. When you master this process, you can make some radical transformations to original parts: The original '59 A-arms, caked with grease and dirt, rusted and rotted The same '59 A-arms after going through the above process, rebuilt with new bushings and joints, mounted on the frame. Look brand new, don't they. Every bit as nice as powder coating, but spray painted for a total cost of $9. There you have it. Those are my spray painting secrets. Hopefully you found this informative. Now go restore something old and cool back to its former glory! Cheers.
If you have to spray a big area the 'ol index finger will start to feel it. I have found that if you hold the can like a beer and use your thumb to push the sprayer you can paint alot longer with out getting tired. - Joe (painted my car with rattle can) Poutous
Great post. I've found that having one of these is REALLY helpful if you're going to use a lot of cans:
hahaha i've never seen a gun like that. you can get different caps though. some are hooded which are easier to spray for a long time. some will empty a can faster than you ever imagined with a spray 6 or more inches in diameter.
if your trying to get a good spray out of a rattle can your index finger should be killing you, you need to press the ****on on each p*** as you go back and forth left to right, right to left about 8" p***es. and dont bother with anything other then krylon or rustoleum
It also helps if you soak the cans in a 5 gallon bucket of just hot enough to touch water for about 20 mins It makes your paint flow like gl***!!
I like to pre-heat my parts/primer/paint to at least 70 degrees. I actually prefer closer to 100 degrees. For small stuff and spray cans, I set them on an electric baseboard heater for ten minutes. Like stated earlier, the paint flows like gl***.
I like to hang the parts in the sun prior to painting, then move to a shady area to paint in.a warm part takes paint better and helps reduce runs from my experience.. the best tip in here is once painted, leave it alone at least till tomorrow! Im always eager to bolt stuff together before its dry..bad habit!
The Jalopy Journal
