[68ragtop]

Tomorrow I pick up my 68 GTO shell. It should be completely clean after media blasting. I intended to use a metal prep, & then use PPG's DP 40 series epoxy primer. From what I have read, PPG makes metal ready, & metal prep. Is there a generic solution for these, & what should I use? Is it just a neutralizing acid? I am a little grey on this.

Thanks, 68

[68ragtop]

Tomorrow I pick up my 68 GTO shell. It should be completely clean after media blasting. I intended to use a metal prep, & then use PPG's DP 40 series epoxy primer. From what I have read, PPG makes metal ready, & metal prep. Is there a generic solution for these, & what should I use? Is it just a neutralizing acid? I am a little grey on this.

Thanks, 68

[68ragtop]

I was just doing some reading on PPG's site & the DX579 metal prep, requires a dilution with water, & then rinsing the metal off with water. The car body is going to be stripped to bare steel everywhere, I am not to thrilled about bringing water into the picture [img]/infopop/emoticons/icon_eek.gif[/img]

There are so many little area's that could end up with water & no metal prep. No I really don't know what to do.

68

[Glenp68]

What you want is ppg 1791 primer wash before the epoxy primer. It's a metal etching primer coat.

[fast1970transam]

samething happened to me, i had the body stripped and then i did that metal wash with water, it turned like a rusty color. so i had it sandblasted again and took it to a body shop for the prep work, which is not to cheap. i payed 700 for the prep and primer.

**** breaks, then u buy the good stuff

[george kujanski]

Years ago when I did mine, you first used the "Metal Prep" which is a phosphoric acid based solution. It cleaned the metal and etched it, I could see the surface starting to turn a light brown right away. A "conversion coating" was then applied in the same manner with a Scotch Brite pad, again it was a phosphoric acid based solution. Rinsed it off with water & dried. The conversion coating left the metal such that it did not surface rust. A week later I applied the primer, etc. Today, both parts (prep and conversion) are in one bottle, only one application needed.

Regards, Georg

[Marty Phipps]

Don't know if this will any of you or not.
But the majority of the new bare metal prep primers are Isopropyl alcohol based.
Quicker solvent evaporation, a little more water
" friendly"
Which helps if you live in a humid envioroment (like Oregon"
I can remember years ago, where we'd use vinager to prep galvanized metal before priming

[stu]

I use Martin Senour (NAPA) or DuPont phosphate conversion coat, it goes on with a brush or sponge, then is buffed off with a damp rag. I think it puts an iron phosphate coating on the surface of the steel, which inhibits oxide formation and etches the surface to promote adhesion. If you ever carefully and fully strip a factory panel, you can see the same darker gray finish. I have had very good luck with this, but it can be tricky to get right. For instance, if you water wash instead of dry buffing, you get the yellow/brown oxide. The key is to keep excess water off (or any water really). I used to lay down primer over bare steel and if it got a chip or scratch it would start rusting and never stop until you sealed it up. Also, it was prone to chipping. All this being said, I prefer the self etching primer for convenience but still think you should conversion coat if you have time.

[Nogoat]

All I can add is SAFETY FIRST!! I got phosphoric acid in my eye. Very scary. I truly thought I lost the site in that eye for good. Very sore for a while, a bunch of doctor visits, but its 100% As for metal prep I used it on a stripped fender that sat in my shed for a few years and no new rust.