Should you prime PE parts before painting?

Tools, Techniques, and Reference Materials Techniques
1

Hi everyone,

I got a whole bunch of photo etched parts from Eduard for my visible B-17. What is the best way to paint the PE parts? I’ve used small PE parts in the past with average results but I often had problems with paint adhesion. Any tips or advise that you guys use to make it work out better?

Thanks!

Eric

2

some people do and if i remember corectly they use a metal etching primer, and have no idea where to get it.

3

That sounds like a good solution. I wonder if a local auto paint store might have some of that stuff.

Thanks for the tip!

Eric

4

Generally I don’t find it necessary to prime PE (for ships) before application. I spray the whole fret while I paint the model. I then cut, bend & apply. The cuts and any nicks/cracks from the preparation are hand touched up after application.

I prefer to use Aleene’s Tacky Glue from the craft store to tack the parts in place. When that is dry go back wit some CA to firmly affix the part. A dust of clear flat kils any shine from the CA.

5

I find that sometimes a wash with vinegar helps etch the metal to take paint better. Just don’t use it on prepainted PE. Rinse after washing with vinegar to stop the reaction.

6

Hawkeye, how long should you leave the PE in the vinegar for? Last time I tried that, I actually forgot about it, and came back about 3 days later, and found my PE fret greened out with hard residue (d’oh!), which was ok after I scrapped it off with a razor blade! Didn’t want to go that route again…

Bill

7

Just long enough to get a foggy look…the vinegar actually etches the surface which provides a sure grip surface for the paint to bond to. Usually I find no more than 15 minutes adequate…depends on the type of metal used…brass and aluminum are very different.

8

how well does the vinegar trick work with glue? i found most of the parts put on with the CA glue are easy to knock off, so i started sanding/scratching the parts which sometimes damages them.

9

The trick with the etch is to get the surface residue off. So weather you prime it with a metal primer, etch it with vinegar or lightly sand the parts with an extra fine sanding stick all you are doing is removing or eating through the chemicals used in the etching process.

I will prime or sand mine. Just easier for me. But when I lightly sand them, the grab of the CA is several times better.

10

Thanks for all the great tips! I especially like the vinegar information. I will give that one a try for no more than 15 minutes. The frets I ordered were for the Eduard set which covers the rear half of the B-17 from the ammo boxes for the ball turret all the way back to the tail gunner’s position. I’d say 2/3rds of them of them are unpainted brass while the rest are the colorized version. Those I obviously won’t paint or treat. I’ll soak the unpainted ones in vinegar, rinse them off, paint them, then give them a good flat coat to seal it all. Hopefully that’ll do the trick.[:)]

Thanks!

Eric

11

Gerald, I was wrong. The PE set I have is Aluminum. Does that mean I should soak the frets longer or shorter than 15 minutes? What would you recommend?

Thanks,

Eric

12

Is it aluminum or is it nickle-steel? Aluminum is very reactive to FeCl etching solution (I know - I’ve tried it).

A bath in lacquer thinner to remove the skin oils from fondling the fret followed by allowing it to air dry should do the trick W/O the vinegar bath.

13

Don’t over think it. I have never primed photo etched in the 18 years or so I’ve used it.

I do however paint with MM enamels with a brush, not acrylic paints.

I thin the enamel very little to avoid clumping (ships railings for instance), and almost always have to do some touch up.

14

I certainly do not have the experience in modeling that the other responders to this question have, but I can offer this: if you have decided that priming is necessary, any auto paint supply store will have “self etching” primer, that does exactly what it says. The only problem may be that since this is designed for automobiles, thinning it to a consistency required for a small scale model may or may not work well. Anyhow, it does exist.

15

Vinegar etches aluminum very well thank you. Been using it on 1 to 1 aircraft for years.