Last Updated on December 8, 2020 by Dave Farquhar
I’ve gathered a lot of spray painting tips over the years but I’ve never seen more than 10 collected in one place. Spray paint is a tool, and using it is a skill you can learn. With a bit of practice, you can get enviable results and make the object you’re painting look better than new.
Whether you’re painting something for your house or for your hobby, here are more than 20 spray painting tips to help you paint with the best of them–in the order you’re likely to need to use them in your projects.
Spray painting tips
- Don’t paint in high humidity or when the temperature is below 50 degrees Fahrenheit/10 degrees Celsius. If you need to paint in those kinds of conditions, apply the paint outside and then move the object indoors to dry. Cold temperatures inhibit dry time.
- If it’s too cold to paint outside, paint in the garage, but lay down dropcloths to catch any overspray. Wear a respirator mask if you are painting indoors. Don’t negate the health benefits of enjoying a hobby by inhaling harmful chemicals.
- Before priming or painting, sand down any high spots and fill in any low spots with putty, such as Squadron Green. You can repeat after priming. Consider using different colors of primer for subsequent primer coats; then you can tell how far down you’ve sanded.
- If the piece has been sitting around any significant period of time, has been handled, or you have to sand it, wipe it down with a lint-free cloth dampened with mineral spirits in between coats to eliminate dust and oils.
- Warm up the paint can. The can should never feel cold to the touch. Cold paint won’t go on smoothly. You can float the can in a sink full of warm water, or heat it up with a hair dryer.
- Shake the can for at least a minute. If it feels cold after you shake it, warm the can up a bit more, then shake again before painting. Not shaking the cans causes improper paint mixture, leading to thin paint and waste. You can waste 20 percent of the contents of the can, or more. A Mixkwik tool will shake a can with a reciprocating saw, giving more thorough results than you can get by hand. If you paint a lot, a Mixkwik pays for itself after 25-30 cans if you place a value of $0 on better paint results. Most of the complaints I see about cheaper paint can be overcome by shaking the can. The biggest difference between cheap paints and premium paints is that the premium paints are more tolerant of poor mixing.
- Warm up the object you’ll be painting if it feels cold to the touch. When painting metal, if the metal is hot to the touch, thin coats start to dry almost instantly, before they get a chance to run.
- Get the object up in the air so you can spray it while you’re standing up. Try making a stand from scrap wood and hang the item from a hook made of wire.
- Prime, then paint. Primer sticks to the object better than the paint does and fills in small imperfections that the paint would bring out. It’s best to use the same brand of primer and paint, but if you can’t, test the combination on a junk object first to make sure the two are compatible.
- When choosing a primer color, white gives a brigher, more vivid finish. If you don’t want a bright, vivid finish, use gray. Or you can use a red oxide primer to get a better red finish if you’re painting something red, or a darker finish if you’re painting it green.
- At minimum, follow the directions on the can for how long to let the primer dry before painting. But for best results, primer takes four days to fully cure at room temperature (70 degrees Fahrenheit/21 degrees Celsius). You can accelerate this to 12 hours by baking it at 120 degrees Fahrenheit/49 degrees Celsius. Use an old toaster oven (make sure you won’t be using it for food again), or better yet, a wooden box with a light bulb in it. Use a thermometer to make sure it’s not getting too hot inside the box.
- Apply your coats in two passes instead of one. Apply a thin, translucent coat, then move to another side, working your way around all sides of the object, then come back for a second pass, working all around. You’ll get fewer paint runs this way.
- Clear the nozzle after use. Hold the can upside down and spray a couple of short bursts until it runs clear.
- If a nozzle gets clogged, pull the nozzle off the can and soak it overnight in a bit of mineral spirits. This is usually enough to clear the nozzle.
- Don’t be afraid to sand and putty in between coats if the results aren’t initially as smooth as you like. Paint can expose imperfections in the surface that weren’t visible at first. And if you get paint runs despite all your best efforts, you can sand those down and then apply another coat to even out the finish. Be sure to wipe it down with mineral spirits after you sand.
- Be sure to wait long enough in between coats. Generally you will need to wait about 24 hours for the paint to be dry enough to sand and putty and then recoat.
- Let the paint dry thoroughly before assembly and/or use. If the paint feels tacky, it’s still wet. Most paints take a week to fully cure at 70 degrees Fahrenheit/21 degrees Celsius. If you don’t wait long enough, you will mar the paint during reassembly.
- Heat speeds up dry times to a point. Just like primer, raising the temperature 10 degrees Celsius roughly halves the time required, but when baking, don’t exceed 120 degrees Fahrenheit/49 degrees Celsius. At that temperature, the paint will fully cure in about 21 hours.
- If you’re painting multiple colors or need to not paint part of your work, mask it off with tape. Blue or green painter’s tape gives a better result than the old tan masking tape did. For really straight painted lines, do this: Apply the tape to a flat surface. Cut a line with a utility knife and ruler. Then apply the tape to the surface you want to paint. Burnish the tape edge with a burnishing tool or a pen cap to really snug it down and prevent bleeding. Finally, consider applying a clear coat before you apply the paint you want. This will slow you down but it will give you better results.
- Test, test, test. If you’re doing an ambitious job involving primers and clearcoats and/or multiple brands of paints, do a trial run on a junk piece first. You don’t want to be 90% done and then find your clearcoat made the paint bubble.
- Try different brands. Not all brands of paint behave exactly the same. Selection varies too–try hardware stores, craft stores, and auto parts stores. You may find the color you want someplace completely unexpected. For example, hardware stores no longer carry a good match for the semi-flat black that Lionel and Marx used on its postwar locomotives. But auto parts stores do.
And those are my favorite spray painting tips, collected from years of reading, working with other hobbyists, and my own experience. I wish you the best on your project.