Metal Primers

[mcs1056]

I'm headed toward my first photo-etch job, and wonder about metal primers.

First; Do I need one? I stopped by a mom-n-pop hobby store, looking for Tamiya Metal Primer. They had none. "Pop" said I didn't need it, and pointed me to Surface Primer. 

Second; If I do need metal primer, is Tamiya the way to go? I've read that Zero Paints doesn't stick, and that Mr Metal primer doesn't dry. Stynelrez is reviewed as a primer that LOOKS llike metal, but isn't made for use on metal.

Third; Am I making too much of this? Sometimes I fall into product traps (can you say, "Godhand Sanding Sponge?")

[sidcharles]

we all do that; "they're" counting on it.

i was looking for a pounce wheel and the Big A had a dozen styles/ options. one was around $18 for a set of three. Mico-Mark had the same set for $29. of course if you belong to the NMRA, they'll give you 10% off .....

but to your point: when i use photo etch, i always give the piece or entire fret a dusting with 400 or 600 grit sanding sponge (whichever is handy).

stick it on, and then prime. depending on its location, either Tamya rattle can or whatever color Stynylrez is going on the big part the detail is adhered.

i don't rough handle my models, and if something were to chip, i would simply touch it up with a brush.

[Ace-Garageguy]

I just use real automotive self-etching primer on everything metal.

Duplicolor or SEM or Transtar, usually green 'cause it looks like zinc chromate.

Big can will last about forever.

Make sure your metal is clean. Adhesion to bare metal can be iffy.

Wiping whatever it is with vinegar can sometimes enhance adhesion.

Scuff-sanding is good too.

Edited October 20 by Ace-Garageguy
punctiliousness

[mcs1056]

Ooooh! I have a case of the SEM Self-Etching in the garage. Didn't even think of it. 

[peteski]

What kind of photo-etched parts are we talking about?  In automotive model hobbies photoetched parts are usually left in their bare metal state (things like grilles, scripts, emblems, steering wheel spokes, etc.)
I also recall that you dabble in model aircraft?  Is that what those parts are for?  Are those parts brass or stainless steel? What specific brands of paints will you be using?

[mcs1056]

6 hours ago, peteski said:

What kind of photo-etched parts are we talking about?  In automotive model hobbies photoetched parts are usually left in their bare metal state (things like grilles, scripts, emblems, steering wheel spokes, etc.)
I also recall that you dabble in model aircraft?  Is that what those parts are for?  Are those parts brass or stainless steel? What specific brands of paints will you be using?

Small ones.

I do.

No.

Brass.

Tamiya.

Edited October 21 by mcs1056

[mcs1056]

And now...a serious response:

Pete,

I'll first be working with Eduard brass PE on a Hasegawa Voyager Space Probe kit, intending to use Tamiya lacquers. However, my query is in a more general nature, as I haven't dealt with PE so far.  

I watched 3 1/2 hours of build videos while I couldn't sleep the other night, only to get to the point where the dude had melted some plastic and gave up on  the build. He never got to paint. (It would've been nice if he'd have edited the previous videos or added a comment to say he never finishes.)  

Woke up the dog with some choice language when he said, "Sorry, guys."

[Ace-Garageguy]

11 minutes ago, mcs1056 said:

...(It would've been nice if he'd have edited the previous videos or added a comment to say he never finishes.)  

Probably just as well that I don't do YT videos, eh?   

[peteski]

Mike, I have troubleshoot computers (hardware and software) for decades on a professional level, and from my experience I know that the more details one reveals in their request for help, the more accurate advice they will receive. To me there are no generic questions or answers. Especially when it comes to  processes which have many possible combination of chemicals or materials.

Different metals might be treated differently for accepting paint.  For example brass can be "pickled" in vinegar to prepare the surface for better paint adhesion. Can't do that with stainless steel (well, without chemicals which are not in an average modeler's arsenal).

Important thing to remember is to prep the metal parts by making they are free of oil/grease.  A rinse or dip in acetone or naphtha will work well.   Also while not usually the case nowadays, in the past, brass photoetched parts often had a clear coat which remained after the etching process.  That could be left on them as a primer coat for the paint to stick to. In my experience, water-based paints (you didn't specifically state which Tamiya paint line), don't adhere well to any bare metals.  Organic solvent based (stinky) paints can adhere to bare metal quite well, but as Bill mentioned, first using a self-etching or aka. etching primer will improve adhesion of any paints.  Those primers are usually sold in auto body supply shops and might also be available in general auto parts stores.

Edited October 22 by peteski