If the metal parts have set for a period of time I would clean it with DX-579 cleaner and then go over it with DX-520 conditioner. This is after sanding to remove the grit from the metal.
There are several good metal conditioners and cleaners out there and any will work for this. Dupont has a good cleaner too.
These need a water rinse but we use a wet cloth and quickly dry it.
On the interior of the panels(floor pans ,inside doors , inside frame rails,ect) I go with Rust bullit,Zero rust, or POR. I would do these area first so not to get water on them when doing the outer panel prep.
I like to scuff sand after cleaning before going to epoxy. This makes me feel better about how clean it is I also wear gloves for this so not to leave sweat or skin oil on the surface.
Then I would DX 1791 etch prime followed by DPLF- 50 0R 90 it(numbers are just the color).Use the 402 catalyst.
Go to body filler work next. You can reprime with DPLF then or go right to NCP-270 (NCP is a corrosion resistant primer)or K-38, I like the NCP but it is pricey. Fills great and very little shrinking. Both are good products.
After all the blocking/repriming is done we spray NCP-270 as a sealer to wet sand for final prep(600-800 wet). If at this time you find a area you don't like you can go back and repair and reprime with it as a surfacer or reseal and sand. I like this process because at the final stage if you need to fix something you are not layering different products.
If it looks good, prep for final seal with NCS-2004 and go right to color.
Hint: You can let this dry and wet sand again with 1000 wet and go to color if you don't break thru or need to remove dirt nibs.
At each step it is cleaned with DX 330 AND Dx 394. Both are wax and grease removers but the first is for petrolium contaminates and the other is for organic contaminates.Either product will leave contaminates that the other is designed to remove so use both. DX 330 first then DX394.
If you have any more questions or I missed some thing in all this let me know.
Dave
