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Just wondering what effect and finish will I get if I use the Ospho rust treatment on the barrel of an old .22 or any other barrel.
 

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I've used Ospho on rust before. If the barrel is all covered with surface rust Ospho will turn any red rust into a black inert substance. On the bare metal or blued parts of the barrel it will leave a frosted like residue after it has dried. You will have to wire brush off this residue before painting the barrel. If you sand or wire brush the barrel you cannot brush off the inert back substance where the rust used to be or it will rust again. Don't breath in the frosted white residue when you are sanding or wire brushing the metal---stuff is bad for the health. Wear eye protection so you don't splash any in you eyes.

Ospho is phospheric acid---it will burn bare concrete just like battery acid does if you drop it on concrete.
 
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But if done correctly it does return the rust to a metal State ( per say ) and can be painted or applied over with a durable finish type product
 

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I've used Ospho on rust before. If the barrel is all covered with surface rust Ospho will turn any red rust into a black inert substance. On the bare metal or blued parts of the barrel it will leave a frosted like residue after it has dried. You will have to wire brush off this residue before painting the barrel. If you sand or wire brush the barrel you cannot brush off the inert back substance where the rust used to be or it will rust again. Don't breath in the frosted white residue when you are sanding or wire brushing the metal---stuff is bad for the health. Wear eye protection so you don't splash any in you eyes.

Ospho is phospheric acid---it will burn bare concrete just like battery acid does if you drop it on concrete.
Good info! :top:
 

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Is the best way to prep steel metals for painting. Some primers and such just try to seal off oxygen and moisture to try to contain further rusting but the phosphoric acid preps actually neutralize the rusting process. Do heed all the precautions handling and using the stuff though.
 

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All kinds. Enamored of their mechanisms! Worked as an engineering
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Don't get it in the bore. I did a shotgun with Ospho as a prep, then had it powder coated. Looks like am HK 91 finish. AC
 
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