That's kind of an interesting looking on its own.

 

I am getting ready to prime a 65 Fastback with SPI Epoxy. I have spent the last 2 years stripping it to bare metal And repairing all the rust and damaged panels. Since I live in FL where bare metal will rust as you look at it, Literally! I costed it with Osoho. It worked really well.

SPI provides the following instructions!

“Apply Ospho As needed and leave it on as long as you like.
When you are ready to neutralize the dry Ospho apply one more coast of Ospho over the area to be neutralized and let set for 5 Minutes.

using a clean towel and water, wash off the wet Ospho like you are washing a car then dry with a clean towel”

I have done this multiple times, but still appear to have white streaks that I assume are phosphorus.

DoI need to continue doing it? How do I know it is fully neutralized? I know it must be in some areas because it is already flash rusting, and getting a gold sheen that leaves rust colored residue on a towel.

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I suggest contacting Barry at SPI.

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I suggest contacting Barry at SPI.

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I was hoping to paint on Sun. It’s the first dry weekend in months. but if I have to I’ll wait to Mon and call them. The I’m out of town for 2 weeks so I’ll have to find s9me way to keep it from rusting before ai gte the paint on.

I was hoping someone had some experience with Ospho. I just don‘t know what it should look like.

 

Wipe it down with ammonia?

 

I used a different brand of epoxy, but my understanding is if you have a chalky white or black residue you haven't fininished treating it. You need to spray another coat, let it sit for 10 minutes and scrub with a scotch bright pad and then hose off with water and wipe down with wax and grease remover. My finish looked more iridescent after the third treatment. In your case though, I would still contact SPI.

 

It's also my understanding of these phosphoric acid treatments is that you can't let the acid dry before completely washing it off with water. Maybe you're letting it flash dry before the water?

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It's also my understanding of these phosphoric acid treatments is that you can't let the acid dry before completely washing it off with water. Maybe you're letting it flash dry before the water?

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I was very careful to keep it wet, as I had heard that too.

 

I scrub it with a greenie pad while the Ospho is wet.

Put the Ospho in a spray bottle and do a small section at a time.

 

Great idea, I hadn’t thought of the spray bottle. I was considering using a scotchbrite pad. I’ll try a small section and see how it goes.

 

I recommend reading, and joining, the SPI products forum. Tons of info and help over there.... Link below directly to the "Primer" forum

Primers

 

I have been to the forum, but didn’t see answer, perhaps I need to dig deeper

 

I'd talk to Barry directly.

 

If it were me and I was planning on spending lots of money on paint, I’d DA 80 grit that off and expoxy the fresh clean steel. If it’s rusting back quick do a section or panel at a time. Paint fails are sad

 

According to SPI sanding won’t work, you have to neutralize the Ospho. I do plan to hit t(e whole car with the sander before spraying.

 

Definitely shouldn't spray epoxy over that. You are wise to wait to hear from Barry. I would be very surprised if he didn't recommend hitting the panels with 80 grit before applying epoxy. I know you are battling very high humidity there but I think you should now focus on sealing 1 panel at a time.

 

Don't try to neutralize Ospho outside under a hot sun, it will start to dry before it can be wiped off. This is from personal experience. Always neutralize in the shade. I'm in Louisiana, just above sea level, (well sometimes) and it's very damp here. I kept the bottom side of my car in Ospho for almost a year before cleaning it off a painting.

 

Thanks I’ve learned that lesson Just washing a car. I have a canopy up that I am working under.and doing one panel at a time.

 

If it were me, I would not ever trust a layer of converted, oxidized stuff under any primer or paint. I would not trust any primer or paint manufacturer that would recommend a a layer of converted, oxidized stuff under any primer or paint. I prefer clean shiny metal that has been surface prepped with a DA sander and metal prepped. Again, this just me. And I enjoy looking at my driveway paint jobs that have never bubbled up in over ten years. Just sayin'.

 

The SPI instructions more or less say to neutralize Ospho if used first, then follow the normal instructions which include DA sanding to bare metal. You're right about the DA sanding, definitely can't skip that step!

 

And the Answer is,,,,,,, I got a hold of Barry, explained everything I have done and what I am seeing. He was confident that I have sufficiently neutralized it, but I MUST flow up with an 80 grit DA all over the car, which is what I had already planned.

This brings up my next question... What do I use for all the tight places a DA doesn’t reach?

 

Hand sand, wire wheel, scotchbrite.

 

Consider the patina thread ;o)