Painting Photo-Etched Parts

EdGrune

Degrease in a bath of lacquer thinner, then avoid touching the parts with your pizza-stained fingers.  Handle the fret by the frame.    

An overnight soak in a mild acid such as household vinegar will slightly etch the metal surface.   Rinse and allow to air dry (rubbing with a towel may bend fine detail shapes).

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Be careful with household vinegar.  Some of it contains solids.  The term for pure vinegar is, I think, white vinegar.  Make sure what you use is clear, little color, and no powder or solids, like tiny seeds.

BTW, I hate stainless steel PE.  It does not etch well with vinegar or lye, is harder to cut, and does not fold very easily.  I much prefer brass!

Puh, Just to reinforce what you've already heard...Use a primer for metal. You will regret using anything else. Right now, it's easy enough to spray outside, even. Spray sparingly, so you don't obscure detail or have too much build-up on the parts. You just need a light coat. And make sure you degrease the parts before that. Etching with vinegar is a great precaution, too. Barrett

I just prime with a regular model primer, i use Alclad. I've never washed it and not had any issues.

Degrease in a bath of lacquer thinner, then avoid touching the parts with your pizza-stained fingers.  Handle the fret by the frame.    

An overnight soak in a mild acid such as household vinegar will slightly etch the metal surface.   Rinse and allow to air dry (rubbing with a towel may bend fine detail shapes).

The Tamiya spray primer is a good recommendation, although I have had success with well-thinned plain old ModelMaster in a color which complements/blends with the final color.

Use heavy spray primers intended for metal/Bondo auto body work with caution.  They contain fillers  which help blend surfaces when finish-sanded.  However these primers may fill/clog scale detail parts

Ditto to Pawel and Don, and I might add that I can assure you that the Vallejo primer will not adhere well to PE. It will peel off with the slightest of handling.

Just make sure whatever you prime it with is a metal primer.

Hello!

That sanding might not be so easy, those grills can be quite fragile! I say painting PE isn't such a big deal, it's good to wash them with something to make sure grease and such is not there - I use lacquer thinner here. Then the Tamiya primer is great stuff, if you put a light coat on it dries very thin and doesn't plug any details, has a great adhesion, too - I heartly recommend it.

Good luck with your build and have a nice day

Paweł