For some unknown reason a lot of car guys are very hesitant to take the plunge into the world of powder coating. This means a lot of people are missing out on all the benefits powder coating has compared to other types of coatings. It seems like there is some fear of powder coating that is preventing car enthusiasts from buying the equipment and starting to coat on their own. You might be surprised to learn that in some cases it's actually cheaper to powder coat something than painting. The truth is that there are fewer tools and materials needed to powder coat compared to painting. For instance there are many more consumable materials needed when painting and thats not including the paint itself. If you were to compare the differences between painting or powder coating a part for your car, the first step would be to take it down to bare metal.
From here the processes are different, and also vary in the time required to complete each.
If you're coating the part with a traditional 1K or 2K paint the piece must be sealed to prevent corrosion and rusting. Using epoxy primer, which can be applied directly to bare metal is the best option. Automotive paints generally shouldn't be applied directly to bare metal because there could be adhesion issues. If you're spraying the part with a 2K primer you will need the correct activator which means another cost associated with the job.
Ok so now that you went out to buy more activator and sprayed the piece with primer, you then have to apply a top coat. Not only will you need the paint, you will also need the reducer and activator if you are using a 2K top coat. Just when you think you're finally done you realize there is still one more step, applying clear coat. The clear coat requires its own activator as well, that's more money out of pocket if you don't already have it. At this point you think you may have spent too much time and way too much money, but the end result does look great.
With Powder Coating you first make the investment in a powder gun and oven. From there all that is needed is to buy the powder itself. Pretty much any electric oven will work (just don't use one you cook food with!). No special activators, reducers, or other chemicals are needed (other than PRE, to clean the bare metal). Prepping a metal object to paint or powder coat is a similar process, the only difference is that any non-metal pieces must be removed since they will not be able to withstand the heat needed to cure the powder.
Lets see how they match up.
When comparing paint and powder, durability is always #1 on the list. Before we compare the two we first have to mention the different types of paint. Generally speaking, 1K paints in an aerosol can are worlds apart from the paint on your car. Most 1K aerosols paints are usually enamel paint. The down side to enamel paints are that they never fully dry, they just harden when exposed to air. Additionally they will break down and essentially melt if they come in contact with a solvent. The paint on your car is known as a 2K catalyzed paint. This means that before the paint is applied an activator is mixed into the paint. The catalyzed paint will actually change its chemical make up and cure, making it resistant to solvents. While a catalyzed paint is much stronger than aerosol paints it still does not compare to powder.
Once powder fully cures it's much harder than traditional paint, making it much more scratch and chip resistant. There's a reason almost all high-end custom cars have powder-coated frames! A powder coated part that is exposed to extreme conditions is less likely to chip off and peel like paint would.
Powder isn’t just harder than paint, it's also extremely flexible. We've tested the flexibility of powder by applying it to tin foil, crumbling it up, and flattening it back out. The results were incredible, none of the powder had flaked off! Try doing that same test with spray paint, more will end up on the floor than the foil!
One of the visibly noticeable differences between powder and paint is the actual material thickness. A functional coat of powder can be up to 10X thicker than paint. This means that there is a greater protection between the outside world and the bare metal.
When prepped and applied correctly, powder does an incredible job of preventing corrosion because of how strong it is. When a painted surface is scratched it is much more likely to go down to bare metal. At that point corrosion will begin and start to spread. Since powder is so much harder than paint the chance that a scratch will reach bare metal is very unlikely, making it the perfect coating for chassis and suspension parts.
Ease of Cleaning Up
If you've spray painted before, you'll know how awful overspray can be. No matter how much you prepare, it seems to get everywhere. Cleaning up overspray can be very difficult because it requires the use of harsh chemicals. In its raw form, cleaning up powder is no different than cleaning up sugar and flour spilled in the kitchen. Simply sweeping it up or using a vacuum is all that will be needed.
2K paint must be used once it is mixed, powder does not require any additives. This means you can use it at you own leisure. Powder under normal circumstances does not dry out or cure even when it's left out.
If you really want to be frugal, powder that doesn't stick to your part can be reclaimed and reused by sweeping it up and sifting. Just make sure you use a very fine screen to sift so that there are no other contaminants in the powder. This may be very tricky to do at home, but with some care it can be done.
Eco Friendly Application
Traditional paint guns atomize the liquid paint into the air while a powder coating gun uses air to propel the powder towards the part. As the powder is leaving the gun a slight charge is added to the powder. The powder sticks to the grounded part because the powder has a slight charge when it leaves the gun and it's then attracted to the grounded part.
Unlike liquid paints that are sprayed, there aren't any may health threats to being in the same room without a mask on. Powder coating does not even require the use of a typical carbon filter mask, just a simple dust mask to keep from directly inhaling the powder when spraying. Because powder is heavier than atomized paint, overspray will fall on the ground right around the part and won't float in the air for extended periods of time.
Check out the Eastwood Blog and Tech Archive for more How-To's, Tips and Tricks to help you with all your automotive projects. If you have a recommendation for future articles or have a project you want explained don't hesitate to leave a comment.
- James R/EW