I've been told to wipe the panel with lacquer thinner. If it comes off on the rag then take it all off. If it doesn't then it's good to go. Just sand it like you would when your ready for the next step in the many prime and sand stages. That's what I do anyway and the paint is still looking good 20 years later.
I did the Acetone test on the AMD E-coat and the black e-coat came off. I called PPG and they told to remove the e-coat. I'm sanding, media blasting, epoxy primer, and then high build primer.
If lacquer thinner takes it off you need to strip it all off but even if it`s good e-coat I sand it off anyways. I have heard stories of surface rust on the metal under the e-coat. I would not sandblast it though, just sand it off.
Thanks for the input everyone.
Another noob question then... what is the easiest way to sand down body panels? I'm assuming there's a power tool for this?
Thanks!
DA or dual action sander - https://www.harborfreight.com/6-in-dual-action-air-sander-68152.html
Working on the doors today. Media will reach areas that can't be reached with sanders. I like to recover with media to give it a rough finish before applying epoxy.
I would recommend watching Eastwood videos. They have a ton of great ones. Of course they are trying to sell you stuff, but they put out some great information. I also got a couple of Kevin Tetz Paintucation vidoes and those were good too. Cheap used.
The DA sander is great because it isn't supper aggressive like a disk sander. Both are great and fairly cheap. My DA came from Eastwood and I have many cheap harbor freight disk sanders. I think the DA was $30-$50. You might spend more on the sanding paper depending how much you do. LOL.
This is great information everyone! I appreciate the help :thankyou:
Most shops I have talked to remove the E-Coat where possible with 80 grit or sand blasting, then DTM epoxy prime as the base layer. Areas where E-Coat is thick the coating flakes off, some panels it just comes off with solvent, it is better than bare metal, but nothing I would trust under many hours of body work, paint, and buffing & polishing.