Ospho after sandblasting ?

Evil_Fiz said:
I blasted my 1970 Type 1 tins with crushed glass and they look like yours. Mine had the factory finish and very little rust. Either we're both at bare metal or we're both not ;) In fact, my blasted chassis, front beam, and all suspension parts look the same as the tins. I think you're fine.

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Emil
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Great to know thank you !
 
'68 Coronet R/T said:
Yes but it will come off where the threads make contact with the nuts.
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I have these parts from my van- is the best thing to do is shoot these with epoxy ? Not sure what to with these little clips and screws
 
Those clips will break when you install them or shortly there after. You can't use acid on items like that because of Hydrogen Embrittlement.
 
Not to be a contrarian, but I soak clips and parts like that in acid all the time to parkerize, and then soak in ATF. I’ve been doing that for years. They’ll be fine. Hydrogen embrittlement isn’t an issue in steels like that.
 
Lizer said:
Hydrogen embrittlement isn’t an issue in steels like that.
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I wouldn't argue you if not for the fact that it has happened to me over decades of use, and steels like that are the only ones I have had trouble with.

Just send some clips out to be zinc plated and see how they come back after the shop dips them in acid for cleaning. I must admit though that it might be the length of time they are in the dip. The plating shops use heat to speed it up, and I was using only acid, to clean small parts and that takes time in the acid dip, so a quick dip might be the difference.

I tell the plater that the parts are already clean so skip the acid dip, but sometimes they forget, and some other platers have an assembly line where they require the parts to be wire strung, then they can hang the parts on the moving line and let them go through the whole process automatically.
 
chevman said:
I wouldn't argue you if not for the fact that it has happened to me over decades of use, and steels like that are the only ones I have had trouble with.

Just send some clips out to be zinc plated and see how they come back after the shop dips them in acid for cleaning. I must admit though that it might be the length of time they are in the dip. The plating shops use heat to speed it up, and I was using only acid, to clean small parts and that takes time in the acid dip, so a quick dip might be the difference.

I tell the plater that the parts are already clean so skip the acid dip, but sometimes they forget, and some other platers have an assembly line where they require the parts to be wire strung, then they can hang the parts on the moving line and let them go through the whole process automatically.
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I do my own zinc plating as well, and the acid used for cleaning parts is typically hydrochloric acid. If you compare the pKa (the acid’s dissociation constant which is an indicator of an acid’s strength) of HCl to phosphoric acid which is what I use to parkerize, HCl is on an order of magnitudes stronger.

I routinely parkerize small parts exactly like that in a 40% phosphoric acid solution for the last 10 years, from anywhere from several hr to overnight if I forget about it, no heat.

I used to not even blast them, and put them directly in:


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Since it’s not letting me post pics right, when they come out. I’ve had these clips in service to 10 years now, for example :

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Just sharing my experience with phosphoric acid, the thinner the metal the more the HE effect. Only time I use hydrocholic acid is for lead flux, and it gets neutralized with a baking soda base right away, don't even like an open container of it around bare metal.
 
i must say those clips are holding up nicely. Thanks for the advice guys ! All I did so far with these parts for my van is soak them in evaporust.
 
chevman said:
Good choice for a cleaner, you can leave them in that for a month if you wanted to, Evaporust is harmless to metal.
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Oh yeah I love the stuff. Pour it in a cheap untrasonic cleaner and get it nice and warm , with heat the stuff literally works five times faster.
 
Hey guys. I sandblasted these pieces and had them looking really nice and clean. I had a couple hard to reach spots so I used Ospho as a last step before priming. I sprayed with Ospho and waited 30 minutes. Sprayed the water off. Filled my compressor with air. Dried them as fast as I could with the air. And now they’re covered in flash rust. No way I can prime these now right ? What went wrong ? I had a bad feeling about the water but that’s what the directions said. What do you guys think i should do now ?
 

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That’s why I don’t like using acid pre-epoxy. Because it involves getting bare metal wet.

Just scuff it off and it will come right off.
 
You said acid, but if it is evaporust it will rust quickly. The metal looks shiny in the pictures, so you need to put a scatch on it anyway for adhesion.
 
chevman said:
You said acid, but if it is evaporust it will rust quickly. The metal looks shiny in the pictures, so you need to put a scatch on it anyway for adhesion.
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For this piece I used Ospho ( phosphoric ) everything looked good until I washed it with water. It rusted within 2 minutes. I took some Ospho on a rag and wiped it down and the rust came right off it looks good again. Yet now has acid residue on it. So I’m gonna try to scratch that up with some 80-100 grit I have laying around then clean it with automotive prep cleaner then epoxy. Chevman didn’t you say you just wipe phosphoric acid off ? I could be mistaken
 
JohnMartin said:
have laying around then clean it with automotive prep cleaner then epoxy.
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Automotive prep cleaner? You're not following the directions, whose fault will it be if your paint job fails? IMO you need to worry less about the flash rust and more about not following the ospho instructions.
 
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