POR-15 on newly media blasted metal

[OregonNed]

I apologize in advance, as I know there are many threads on the POR--15 subject - but I could find this question answered on them.

For newly blasted metal work - can I apply PO-15 directly without degreasing and using there etching wash? The metal is clean, and I would assume the same as etched (if not better) than with the chemical. There are no traces of rust whatsoever. I just don't want to purchase chemicals that aren't needed.

Thanks in advance.

[Gromit]

Since no one else has jumped in yet; I can offer my opinion.. When I looked into this I came to believe that a two part catalyzed polyurethane primer was the most cost-effective and durable coating to use assuming one can get reasonably close to clean and treated bare metal.

And for this I would always recommend Southern Polyurethanes Inc. out of I think Georgia or near there (I have no affiliation other than as a satisfied customer).

They have very specific metal prep instructions on their site for this type of primer.

They also sell small quantities directly to end users and they are patient with questions.

This primer can even be brushed on if it is in an area that is not going to be visible - such as inside of door or the inner cab corners or beneath the floor mats; battery tray etc.

[Gromit]

I forgot to mention that if you decide to use a two part catalyzed polyurethane make sure you have a brand new fresh cartridge of the proper type in your respirator before mixing it up or especially spraying it.. 3M has the right ones and probably SPI can advise you as well.

[57taskforce]

I would etch it if it were me. You could use an etching primer of you didn't want to do the wash, then Por or whatever else you want to use over the etch.

[leddzepp]

I have used POR for years. Use the etching wash, follow the instructions.

[OregonNed]

Originally Posted by leddzepp

I have used POR for years. Use the etching wash, follow the instructions.

Thanks for all of the advice gentlemen !
Posted via Mobile Device

[dazza]

I used the etching wash on my bed but didn't purchase more when it came time for the frame. I did use a wire brush/drill and went over the whole thing (didn't blast it because I was only going to "do a few spots" ). No surface rust when done. I then did a thorough cleaning with alcohol. So after a few years (slow build) and still not moved from garage, I found that the Por-15 has adhered extremely well... except for a few minor areas which are either tight corners or very difficult to reach, so I believe those locations were not properly cleaned of dirt/grease/grime, and the Por-15 could be peeled off.

[OregonNed]

I will for sure use the wash to etch then. Degreaser won't be needed at least. The main parts I am doing are the cross sills that will go back under my new bed. Someday someone will look under there and think damn, those look good

[oldchevynut]

X2 on following POR's instructions to the letter.

Especially if sand or any other media containing free silica was used for blasting as the metal now has silica imbedded in it, which will cause adhesion problems without the wash being used first.

[dazza]

Did you know that Por-15 sells a rattle-can paint as well? I noticed my auto paint store started carrying it sometime last year, the color is what I was looking for, but other than the name, I was having trouble justifying $26 for a rattle-can! Somehow I talked myself into it and I think it was worth it, well, it looks great and sprays on even and thick, leveling nicely, but worth $26. a can? If it holds up to the elements, I think so.

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