I used Eastwood 2k Extreme Chassis Black https://www.eastwood.com/eastwood-2k-ceramic-chassis-black-kits.html in lieu of undercoating in the wheel wells (and on the bottom of the car). Mud guards are also coated with this stuff. Should be much easier to keep looking nice. I might apply a stick-on rubber/vinyl padding directly above the tire to mitigate the potential for a dent in the bonnet surface from a stone…owners of steel fender hot rods use this technique.
Well, I wanted epoxy primer on them, and the “open” period for recoating the epoxy is fairly short. So there wasn’t much choice.
I was thinking of something along those lines, maybe something magnetic so that I could install for driving and take out for shows. Thanks.
Got it. I’m overthinking this because I only want to do it once. I am running into epoxy window time for applying color vs having it be dry for assembly before color.
And all of that because to some extent I trust my skills enough that I don’t want to give it away to a shop and HOPE that they do what I asked of them.
Ok, some more help please folks. I’m using PPG products and according to one of their documents I should wash with soap and water, then use a metal cleaner ( SX 330), then go with a metal prep ( SX 579), RINSE with water, then paint with epoxy primer. One part of the document states that I have 8 hours after metal treatment (Phosphoric acid wash unless I miss my guess.) and another part says that I have 30 min before metal rusts.
So what should I really do? Any professionals out there?
Thanks.
And some pics of the setup…
And that nasty rust looking stuff is what I think PPG refers to when it states “Leaves a rust-colored phosphate coating BUT it is NOT rust!” But I am nervous about painting over that.
If PPG says to fo something…do it.
My first attempts were like what you show in your photos…it left a powdery yellow smudge on a hand towel when wiped after it was left to dry. No way would I prime over that. So on the second effort I kept the metal wetted with metal prep (phosphoric acid) for a few minutes, then rinsed it off and we immediately wipe dried the surfaces (force air dried areas where moisture accumulated). That kept the yellow grunge to a few light embedded stains (no surface residue/powder)… These photos show the etched, rinsed and dried results (just prior to epoxy).
Not a professional. Perhaps Clive will chime in. Adhesion is the primary objective of any lasting paint job. Epoxy primer adhered to clean, bare, abraded steel is a simpler dynamic than epoxy primer adhered to a smoother, phosphate film on clean, bare abraded steel.
Thanks Nick but then I’m not a professional either. However, PPG does seem to have a habit of changing their products and names quite often so as to be confusing…and also, I’ve been away from painting for a while now.
I used PPG DX579 cleaner and DX 520 conditioner. I don’t know about SX products but maybe they are intended for certain compliant areas of the country (EPA regs?)
Here is PPG’s latest custom restoration manual in .pdf form if that helps. This information used to be very difficult to obtain.
https://ppgrefinish-na.uberflip.com/i/462316-ppg-custom-restoration-guide/45
I wouldn’t want to paint over those rusty looking streaks. Looks to me as if the surface wasn’t dried fast enough after treatment. Also, SX579 is listed as a cleaner, not a final conditioner so thee OP should check the sequence.
Hi Clive, long time no hear!
So PPG changes the prefix, DX 579 is now SX 579. Thanks for the link, yes that manual is the one that I used.
From the manual: SX579 Metal Cleaner Document OC-36 (emphasis mine)
SX579 is a multi-purpose phosphoric acid based cleaner and prepaint conditioner for most metals. It can be used to deep clean a metal surface prior to paint or to prepare a surface for a subsequent chemical conversion coating (when followed by SX520 or
SX501). SX579 is blue in color and could lighten over time.
At present I’m working on the assumption that the 579 wasn’t on the metal long enough so I am off to try that angle.
Thanks all.
I used a light “grit” Scotchbrite pad to keep the surface evenly wetted. Then rinsed thoroughly with a garden sprayer. Then dry…immediately… or it will flash rust. Again, a yellowish stain remained, but it wasn’t something I could wipe off the dried surface.
Lester, 579 is a cleaner (first step) and 520 is the conditioner and unless you have a sandblasted or deeply grit abraded surface, you want to use the 520 as well so you get the conversion coating.
This conversion process chemically produces a thin crystalline structure bonded to the steel which is necessary to give the paint something to bite into so it will adhere well. Even though epoxy primer sticks pretty well already, for a premium job, you want to include that step, I think.
If you use a fine scotchbrite pad to apply the conversion, you can feel the surface getting harder to wipe as it becomes more crystalline, and it should turn a dark gray colour when it’s done.
Before using the conditioner to make the conversion, the metal should be really clean and you can test this by watching for any beading as the clean rinse water runs off. The rise water must sheet on the surface, then the metal is clean and ready for the conversion coat. A zinc phosphate conversion is better than iron phosphate for corrosion resistance.
You ought to be able to towel dry a well rinsed bonnet part before any rusting occurs unless it’s really humid where you are.
That is what I recall from when I did the initial priming of Tweety, using PPG products.
I followed their—and pro painter friends of mine—instructions, to a T, and 8 years later, all was still well.
So this morning I started re re metal prepping. Worked a treat if left on long enough, I scrubbed the phosphoric metal prep (SX 579) in with a red/maroon scotchbrite pad. Left wet for 10 minutes and then rinsed. No flash rust! Mixed up the DPLF epoxy primer, let it sit the required 30 min and sprayed away. All parts got their two coats! Assembly and flange bonding this week… maybe.
1 Like
Eric, did you use a rattle can for the nuts and bolts?
No, I used a cheap air brush as I was spraying an epoxy mix. But a rattle can with a good automotive primer does make more sense when I think back on it. I believe I went a little over board. (Your phosphate prep looks excellent).
So here it is assembled ready to mask for flange bonding. Anyone have specifics as to where the oval washers go? I seem to be short on oval washers and have lots of regular flat washers. Also, do the supports between the center and wing bolt on with the flange flush or protruding? (pic shows flange flush.)
Some things to know on reassembly:
It takes about 4 hours to bolt everything back together
Snug, don’t tighten, all wing to center bolts. You will need to push things around to get them lined up.
Use your hand running around the wing to center joint to see if it is roughly in the right place.
Check the back edge to make sure that the wings and center are lined up fore to aft.
Check the wheel arch area to make sure that the hinge section is lined up with the leading edge of the wheel arch.
Make sure that you have something like an awl to help move the spacer washers (Well everything really) into alignment.
A body dolly can move things nicely… heh.
Anything else come to anyone else’s mind?
Same applies to old John Deere tractors…