You've finally decided to spruce up that dull-looking engine bay, but you're caught up in the dilemma of deciding whether or not you want to paint or powder coat those metal engine parts. Before you decide to pull out that rattle can, here are a few facts to consider.
What are the biggest differences in painting versus powder coating, you ask? Powder coating compared to paint is more resistant to impact, moisture, chemicals, ultraviolet light, and other weather conditions. Because of its durability, powder coating also reduces the risks of scratches, chipping, abrasions, corrosion, fading, and other wear and tear issues often associated with paint. Plain and simple, it's stronger and tougher. But the question we often hear from our enthusiasts is: How hard would it be to just strip and powder coat in your garage at home?
The powder coating process begins by prepping whatever parts you're planning to powder coat. It can mean removing the previous paint, and for that we recommend using a chemical stripper like the product pictured above from Jasco. If your manifold has an OEM powder coat, we suggest using a media blaster to remove the factory finish.
After using a brush to apply stripper to the surface of a cast aluminum intake manifold from a project Subaru EJ25 engine, we were able to scrape away the OEM paint.
Here's the manifold in bare aluminum after we prepped and cleaned it with Eastwood Pre. It goes on after the stripper and removes silicone, wax, polish, and grease as well as promotes paint/powder adhesion.
To apply the powder to our DIY project, we purchased an Eastwood Dual-Voltage Powder Coating System. The Dual Voltage gun gives you the ability to coat small areas using the low (15kV) setting or larger areas using a high-voltage setting (25kV). You will need a compressed air source to use the powder gun; 5 to 10 psi from a portable tank with a regulator or a compressor should do the trick.
Eastwood offers over 90 unique colors to fit any project you're looking to conquer. From super gloss to metallic finishes, there's a color that's perfect for you. We went with "Machine gray," similar to Battleship gray.
We highly recommend using high-temp silicone plugs to prevent powder from plugging threaded holes and/or studs. If you've ever powder coated before, you know how much of a pain it is to rethread coated holes.
Most powders need to cure at 400 degrees F after becoming liquid, so to cure them correctly in your garage, you can use an old unneeded toaster oven if the parts are small enough, like these pulleys (do not, under any circumstances, use the toaster oven or any oven in your kitchen to cure powder coated parts).
If the parts you're looking to coat are too big for the oven, consider using Eastwood's Infrared Powder Curing System. We used their 10x8-inch lamp to cure our manifold inside our garage.
We cured this intake in the dead of winter, so we built our own oven by wrapping the setup in foil to maintain constant heat throughout the entire piece. Pretty ghetto, but it worked!
Since the manifold was obviously relatively long, we opted to cure the piece in two sections.
Here's a shot of the pulleys we powder coated fresh out of the toaster oven.
Here's a final image of our powder coated intake manifold ready to be bolted on to our project EJ25 engine. Lookin' good!