Applying cleaner to your engine while it’s still hot can reduce how effective it can be. Working on an engine before it cools is dangerous because it will burn you.
The more you remove from the engine bay, the easier it will be to achieve a professional finish in the paint. Set any components you remove aside somewhere safe until it’s time to put the vehicle back together. Common components you may want to remove are the airbox, intake, alternator, power steering pump, air conditioner, radiator, accessory or serpentine belts, reservoirs for windshield washer fluids and any number of other components that may be accessible from the engine bay.
The airbox is located at the end of the intake pipe that leads into the engine’s intake manifold. If you have difficulty locating any of these parts, refer to your vehicle’s owner’s manual to locate them. Look for any bundles of wiring or connectors and cover them as well.
You do not have to spray the engine, as it won’t be getting painted, but you can if you’d like to clean it up.
Apply more degreaser as you scrub if need be. The metal you intend to paint must be completely free of grease and grime before you can move forward.
Make sure to give the engine bay a thorough rinsing. No degreaser should be left behind. If you spot more grease or grime after the engine bay is rinsed, go back and repeat the degreasing process.
Cutting the metal and welding in new steel is a job best left to professionals. Be sure to wear eye protection and a filtration mask while sanding.
Stripping all of the paint out of the engine bay by hand would be extremely difficult and time-consuming. Make sure to strip the paint off the metal in a well-ventilated space and while wearing eye protection and a filtration mask.
Engine bays often have lots of nooks and crannies, so be sure to get into them with your sandpaper. You’re done sanding when the surface feels smooth to the touch.
If there’s too much sand and debris to remove with a cloth, use a hose to rinse out the engine bay and then allow it to dry overnight.
Large garbage bags are good for wrapping engines. Aluminum can be a handy way to wrap components that stick out of the engine.
Look around the engine bay again and make sure everything that’s not supposed to get painted is covered, and the covering is secured with tape.
Don’t hold the primer in one place, or it may pool and begin to drip. Allow the primer to dry completely before moving on. It will tell you its cure time on the bottle.
Different paint guns and air compressors work differently, so be sure to apprise yourself of how to properly use each by reviewing the owner’s manual or visiting the manufacturer’s website. Be sure to purchase high temperature automotive paint, which you can get from any auto parts store.
Allow the first coat of paint to dry completely before applying the second coat. Be sure the second coat is dry before moving on. Different kinds of paint will have different curing times in different environments. If it’s very humid where you are, the paint will take longer to dry than in dry climates. Some paints are formulated to be quick drying. Read the label carefully to know how long you may need to wait.
Again, be sure the previous coat is dry before moving on to the final coat.
Peel the tape away slowly, to make sure you don’t accidentally damage the drying paint. Leave the plastic over the engine for now.
At least 8 hours (overnight) is recommended, but you should consult the label on the specific paint you chose to be sure.
Be careful not to damage the paint as you install the engine and related accessories.
