Metal Prep for Painting - Conversion Coating (Phospohric Acid) or Not

[jclay]

Do any of you apply a surface conversion coating (Naval Jelly, Ospho and similar) after media blasting and as the step immediately before primer application?

If not, are there any additional steps/suggestions for metal prep (for developing "tooth" in the metal) besides light media blasting and subsequent acetone wipe down for dust removal?

I'm considering a conversion coating after blasting/acetone as the final step before applying an epoxy primer but am interested in the experiences/recommendations of others before proceeding.

I guess it boils down to:
strip/acetone wipe/blast/acetone wipe/prime or,
strip/acetone wipe/blast/acetone wipe/conversion coating/prime

Reactions/Suggestions

I have abandoned the Rustoleum experiment and am switching back to my automotive paints. I'm trying Citristrip for Rustoleum removal.

Thanks,
John

[armyofevilrobots]

Dan Gelbart's video on surface coatings/painting is pretty good:


TL;DR Acetone to remove bulk oils (or at least, I like to do that), then sandblast.

Also nice video because it discusses _why_ in some detail, along with showing tests to show the quality of your cleaning.

[jclay]

Dan Gelbart's video on surface coatings/painting is pretty good:

TL;DR Acetone to remove bulk oils (or at least, I like to do that), then sandblast.

Also nice video because it discusses _why_ in some detail, along with showing tests to show the quality of your cleaning.

Very interesting indeed.

I can see that what I figured would be a reasonably quick re-paint will be a bit more involved and time consuming as I am determined to discover the best selection of individual steps. I'll be doing some test panels and will have decided on the steps before the paint is stripped from the frame.

Any other suggestions or sources of info gladly accepted.

Thanks,
John

[Curt Goodrich]

There's an excellent interview with Rudy Jung of Black Magic Paint on the podcast The Pull. I'd recommend listening. Painters and aspiring painters should be able to glean some useful tidbits.