Primers for airbrushing acrylics?

Discussion in 'FAQs' started by curmudgeon, Dec 15, 2005.

  1. curmudgeon

    curmudgeon Member

    Hi all -

    I recently got an airbrush setup, and need a little help with basics.
    For convenience, I'm learning with acrylics:
    a flat black sprayed onto an old, stripped metal Mantua shell scratches off with the lightest scrape - how should I prepare the metal so that I get a bond?
    I haven't tried yet due to this first failure, but want to know if acrylics will bond to plastic, as is most of my stuff, or does this need a primer/prep also?
    Lastly, does brass require any special prepping/primers?
    Any info greatly appreciated & TIA!:thumb:

  2. jim currie

    jim currie Active Member

    never had to use primer on plastic with acrylics i use black or red oxid automotive primers on pot metal(white metal) and brass.also pickel them in a vinegar bath to produce a slight tooth for paint and CLEAN well with soap and rinse in hot not handle with bare fingers after priming leaves oil on surface.
  3. curmudgeon

    curmudgeon Member

    Hi Jim -

    Thanks for the info - acrylics bond well to automotive-type primers then?

    To All:
    Tech query - other than mebbe finer pigments, since all acrylics are waterbased (aren't they?), what makes some better (pricier) than others? Or are there significant chemical differences?

    BTW, I'm using WallyWorld's flat "Apple Barn/Plaid" - CHEEP!;)

    Again, TIA.

  4. TomPM

    TomPM Another Fried Egg Fan

    One thing I have found with acrylics especially on metal is you have to seal them sometimes between coats. I use Dullcoat, or a matte sealer. I also use the sealer on the bare metal which seems to help. I have to try the automotive primer and see if that works better.
  5. jim currie

    jim currie Active Member

    forgot to add don't get sandable primer it has a very rough surface to it. havent used WW paints but have used craft paints and they seem to work as well as the model paints.
  6. curmudgeon

    curmudgeon Member

    Hi Tom -

    Thanks for the reply - experienced folks here are saving me a lot of experimental grief.:thumb:

    On sealing - can a sealer bonding to a paint *not* bonded to the metal prevent the paint from still easily coming off?

    And Jim - tnx for the note on sandables - sure don't need to add probs!:D

  7. 60103

    60103 Pooh Bah

    Curmy: I use the acryllics for scenery mostly, and I just go for the ones on sale. I think some of them may charge more for having a specific range of colours. I look for sales at Michael's when the usual $1.39 to 1.69 (Cdn) price drops under a dollar. I stock up if it gets to .69.
  8. nachoman

    nachoman Guest

    I generally don't like to airbrush acrylics. I live in a dry climate and some paint inevitably dries inside the airbrush and cloggs it before I can get it clean. Once acrylic is cured, it is difficult to clean. Acetone works, but it may damage any plastic or rubbber seals in your airbrush. In more humid environments, acrylics dry much slower. I also do artistic painting (on canvas) and when the weather is real dry, I can't get the working time with acrylics that I want.

    For brushpainting models, acrylics are great. The only drawbacks I see are that sometimes it is easy to rub the paint off of coners on overhandled models. It is great for making washes and weathering, or painting overcoats, as the second coat will not mix with the first coat.

    I have painted die cast models before, and the best way I have found to make the paint hold is to "bake" it on in a warm oven. Primer is not a bad idea, but baking the paint on does wonders.

  9. Russ Bellinis

    Russ Bellinis Active Member

    With regard to the earlier warning about not getting finger prints all over a freshly cleaned body before painting, get latex or nitrile gloves and wear them to handle your projects with once you have them cleaned for paint.
  10. curmudgeon

    curmudgeon Member

    You guys are really great - but whada-h..l you doin' up this time o' nite!!?? :D

    Russ - have latex gloves for mechanicing - note to self : mem to use 'em. :thumb:

    Kevin - I eat canned chili 'cause I can't cook - what temp/time works for you?
    Ever try it on plastics?

    David - WW stuff is under $.50/2 oz. - lotta practice real cheep. :)

    Many thanks!

  11. nachoman

    nachoman Guest

    no, absolutely do not try baking paint on a plastic model!! I have had models melt just sitting in the arizona sun. It's been so long since I painted a metal model...but I think I put it in the oven about 200 degrees for about a half an hour... It's a common technique I read in a magazine, and I have the article somewhere, and I think I will have to look it up next time I want to paint something!!

  12. curmudgeon

    curmudgeon Member

    Thanks Kevin -

    Duly noted - more grief avoided!

    BTW - nice lunar shot - usta know the names of many of those features - OH! SO MANY moons ago. :D

  13. TrainClown

    TrainClown Member

    Hi guys. I just thought I would add my own thoughts.

    1: wash parts to be painted with soap and warm water. I have heard some guys give as rinse with vinegar and this helps open the pours to help the paint stick.

    2: Sand lightly with 400 grit sand paper. where you can easily. Helps the paint stick, giving the surface more tooth. Do this before you wash with warm water. In fact, wash with warm water, dry it, sand it , and wash it again. The first wash removes any oils that could clog your sand paper.

    3:The difference between cheap acrylic and expensive stuff is how fine the pigment is ground, and there for, how well it covers. I buy Ceramcoat. Other stuff just doesn't compare. Worth the extra cost, as it saves you fussing around with extra coats, and you get a covering layer that is thinner.

    If you get acrylic paint or latex that dries and becomes a problem, in your air brush, in your paint brush, on the carpet or in your cloths. There is a commercial remover they sell at paint supply stores. It is called "Goof-Off" and it melts water base paints and dose a real good job of removing it. Makes it swell up and disintegrate, and you just wash it away with warm soapy water. Be careful though.....Toxic fumes.

    TrainClown ;)

    Attached Files:

  14. curmudgeon

    curmudgeon Member

    Thanks TrainClown -

    "Goof Off' will be worth having around for cleanup -
    I'm way too much of a goof-off not to take an easy way.:thumb:

  15. ezdays

    ezdays Out AZ way

    Just plain rubbing alcohol will disolve acrylic paint. I use it occasionally to remove a paint job that I don't like or one with too much paint build-up. I also soak a brush in alcohol that has paint build-up in it, or one I forgot to wash out and it does a fine job of restoring the brush. I've never used it on my airbrush since I haven't used it for more than practice so far, but I would think if you soaked an airbrush in alcohol for a while it would soften the dried paint and not attack any plastic in the process. The first time my airbrush clogs up, I guess I'll find out.:D
  16. TomPM

    TomPM Another Fried Egg Fan

    I have had mixed success to be honest. I have been looking for a few other things to try and now thanks to this thread I have a few.

    I have to use the acrylic piants because I have no place or way to vent the fumes from solvent based paints. I can use Dullcoat or other selaers but only in small quainties.
  17. curmudgeon

    curmudgeon Member

    Thanks guys -
    Don - alcohol is cheep & obtainable just about anywhere.
    I'll try it to remove my failure. :thumb:

    Tom - ventilation is why I chose acrylics for learning, too & that's what I suspected about a sealer - thimk I'll try the vinegar etchbath first, then if no go, auto primer .

  18. jim currie

    jim currie Active Member

    Don use everclear (180 proof) instead of rubbing alcohol works great . also use it mixed with distilled water to thin acrylic when spraying the more everclear the faster the paint dries,the only problem with everclear is it is extremley flammable, and don't know what the price would be as i get mine in mexico for 1.25 a liter.

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