Long story ... But a friend got talked into wet sandblasting his car... It's supposed tone done with a rust inhibitor chemical, blah blah ... Well it flashed almost right away.. . So now his plan is to scrub the whole thing with metal prep before xpoxy primer ... Well the directions are to rinse with water which seems odd ... It flashes with an orange haze ... Is there some trick to the stuff? I have heard of guys not rinsing and just wiping it off but that seems like the acid wouldn't be neautalized... I'm going to end up helping paint it I would rather the paint stick and not come off in sheets or rust underneath ! Please help!!!.... thanks!
Hey, Prepped metal shouldn't have an ''orange haze'' I'd go with a metal prep that cuts all the rust, and leaves a whitish film on the steel to protect it prior to priming. Be sure to select a primer that can be shot over a metal prepped surface, not all of them can!
Yep ... That's whats in my head also ... On small pieces if its rinsed and dried with an air nozzle it looks fine... With a slight white haze... But if it takes more than a minute or so to dry... Like a fender , it will haze .. I have read on other forums people using thinner or wax and grease remover to rinse..because of the same issues. But that's not in the instructions... Seems risky at this stage gonna call ppg tomorrow. ...I already have a feeling they are not gonna be a help though Using ppg dp epoxy used it a bunch after dry blasting... This deal however is a major malfunction... I'm not a fan of this wet blasting needless to say
You have to add the rust inhibitor to the water when you wet blast. I just did the whole bed of my truck last weekend and didn't primer it till the next day and there was no flash rust and I live in a high humidity area.You have to follow the correct procedure or you just make more work for yourself.
I've seen the orange haze. Rinse small areas at a time scrubbing the flash rust and orange haze with scotch brite and plenty of the prep. While still wet with prep use plenty of clean water to rinse and scrub. Immediately wipe nearly dry with clean large absorbent cloths or squeegee the surface quickly. Immediately use large amounts of compressed dry air to finish the drying. Repeat on next area or small panel.
Good advice. And then, just prior to epoxy priming, I would scrub the surface with a dry scotch brite following by a liberal wipe with lacquer thinner on a lint free rag.
not familiar with PPG DX520 prep but it sounds like there may be phosphate in it if it's leaving a yellowish/orange tint to it. I own a powder coat shop and when we use phosphate it leaves a yellowish/gold tint to the metal. Manufacture claims it's normal and doesn't effect the bonding of the top coat.
If you use prep & etch from KLEAN-STRIP, Diluted 1to3 pray the metal down , scrubbing with a red or gray scotchbrite. Wipe off all the mess. Spray it again, let it set for about five min, then you can spray with fresh water & wipe dry. This should stop any rusting. If you are not sure if your primer/sealer will bond, scotch brute with pre cleaner & a grey scotch brite. I do this no matter what as it removes all contaminates.
I've experienced the same tint after using and neutralizing Ospho on my front axle. As mentioned above I think they all use phosphoric acid as the active ingredient. I hit it lightly with steel wool and it was gone. I didn't think I needed to but I was curious what the metal looked like. I wanted to just clear coat it... As I was taking the tint off I wondered if it was part of the metal protection or just residue from the 'prep'. I decided I didn't care. My reasoning (or was it justification) ended up with, "If I could easily remove the surface tint (I'm not sure its really 'rust') with a scuff pad it wasn't all that adhered in the first place..." and I wanted my epoxy as THE first layer against the metal. That was a main reason for using epoxy for me. It sticks and I can't wipe it off with a scuff pad... unless it's still wet.
Thanks for the replys guys.... I called ppg today and they told me the Procedure is to go over it with dx579 (cleaner)then wash with water then go over it with the 520 then wash... They still said nothing about the flash I was getting but wouldn't talk to me cause I was "doing it wrong" ....told me it was a metal conditioner and would do nothing for rust.... At this point my friend got irritated to the point of taking all the parts to a dry blaster ... It sucks but i think its probably the smartest thing... Don't need any "miracle " chemicals coming back to bite the paint in the ass!
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