Im replacing the trunk section in my 71 chevelle with one from a donor car and I have sanded it clean. The replacement is in great shape but has minor piting in places a the metal appeares to be stained from rust in places.I prefur not to use por 15 here as I want to put the splater finish back on and I here nothing likes to stick to the por. Im planing on using metal eching primer then dp 40 and finally the splater. Is there some way to ensure rust dosent come back or is this procdure going to do the trick. thanks

Sheetmetal. The proper way is to remove the rust all the way. You can media blast (spot blaster) or use muriatic acid (perhaps metal ready from POR?) and clean thoroughly with water.

As for the paint.
On bare metal use a wash primer and cover that with epoxy primer.
If rust cannot be removed use POR. As far as I know you can cover POR perfectly with other paints. (Because of the lack of UV resistance POR states you should cover POR with a top layer.)
The splatter paint should be covered with a clear coat because it will not be resistant to water.

I am in the same situation with my trunk. After wirebrushing and attempting to remove the rust from my trunk there is still pitting which will probably rust again. I wanted to use POR-15 but have heard that others had problems with painting over it. Are there some tips and tricks to topcoating POR-15 with paint? THANKS!

sheetmetal, I think what you have planned is just fine. Unless some moisture can get under the primer the rust won't grow. Sealing the seams is a much bigger concern of mine.

I have never been one to think that metal needs to be completly void of any rust discoloration. If you prime it with an etching primer, IT contains acid the same as a "conditioner" (like "Metal Prep") does.

Again, the seams should be the big concerns. If moisture gets under them, it WILL work it's way under the primer and rust.

Rusty66, the splatter paint in an aerosol can isn't waterproof but ZOLETONE is. It is available in quarts and gallons and will hold up. The stuff they put on at the factory is waterproof, right? http://www.chevelles.com/forum/smile.gif

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1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
"Fan of most anything that moves human beings"

Guys.. one extra thing.. POR makes a product called "Tie-Coat" that you supposedly put over POR once it's tacked up.. Supposedly you can (after applying "Tie-Coat") paint over it without the issues with painting over POR 15.. I do plan on trying it.. but it will be some time before that happens.. But also I too believe the same as martinsr, that once you etch the area, it will also kill the remaining pits.. and as long as water can not penetrate it won't grow and come back.

You can apply any paint over POR15. Most paints are moisture permeable but POR15 actually hardens with moisture and is impervious to it.

The simplest way to topcoat POR is to apply a dust coat when it has dried enough to provide a light finger drag. Once fully cured, paint away.

If you allow it to fully cure before applying paint, you either have to sand it (trust me, you don't want to go there, it's not easy to do) or apply their Tie-Coat primer as suggested in an earlier post.

I'm working on my third car now using their products and I couldn't be happier with the stuff. Before discovering POR15, I had to be positive there was absolutely no rust remaining, paint immediately after priming and hope I hadn't missed some miniscule spot that would bubble up two years down the road. Now, I just use the POR and forget it. Have yet to have any rust come through and I painted it on directly over rusted surfaces in many cases. Amazing stuff.

Your plan is a great one. Use the metal etching primer first then the dp40. As for the rust stains you dont need to remove it so it looks like the rest of the metal. Just sand blast it good so the primer has somthing to bite too. I would put on at least two coats of dp40 to cover up those pits or teeth that the sand blaster will leave.
I am like Martinsr you need to make sure that the trunk is sealed up very good. Make sure no tiny pinholes are in your replacement trunk and use a good seam sealer around all those seems.

As for the por15 deal that tie coat primer is great. Coat it with that before any other paint and no problem. As for your etching primer it must be sanded and recoated with etching primer agagin after 24 if you havent topcoated it before that. The same with the dp40 but not for excatly sure on that one, but probably a wise thing to do. Good luck with your project...Eric