Aluminum Spray Painting And Other Pro Tips

Can anyone can provide tips and tricks for spray painting an aluminum swing arm. I'm wanting a different hue see.

1) Besides cleaning the surface, can I just spray paint over the original paint or do I need to sandpaper some of the original red paint first

2) I crashed and make a nick on the arm. I don't have a TIG or MIG welder so I was thinking of putting bondo or something, sandpaper it finish and then paint? No??

I am not sure how big of an area you are painting or to what color you are changing it to. Bondo will work fine followed by a primer over the whole surface especially if you plan a drastic color change. The primer will allow the paint to cover uniformly and make complete coverage easier. Depending on the contours and total area, hot dog rollers might be a better choice for applying the paint. Spray would be better for smaller oddly shaped surfaces. Unless the present finish is extremely glossy, sanding is not needed but wouldn’t hurt either.

Great tips and thanks! I'm thinking indigo blue but that might change. The 2 pieces laid end to end is about the size of a forearm. Thanks for primer tip. I hardly paint stuff and didn't know about the primer part. I'll be picking one up. I'll definitely want the paint to cover uniformly and make complete coverage easier like you mentioned.