Paint/Thinning Question....

Discussion in 'Painting Questions, Tutorials and Guidebooks' started by dneid, Feb 17, 2014.

  1. dneid

    dneid Active Member

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    Hey, Guys,
    Well, I have been playing with airbrush(es) the last few weeks experimenting with thinning and air pressure combinations. As I was doing this I had a question hit me concerning thinning ratios as stated in various posts on the forum. Be patient with me as I attempt to ask. I tend to use eyedroppers and count drops, so all ratios in "drop counts".

    The way I see it, there are 2 ways to "define" thinning ratios:
    1) % as a function of total mix. You start with 20 drops of paint. You add 20 drops of thinner. Therefore the ratio is calculated as:
    %thinned = (drops of thinner) / (drops of thinner + drops of paint)
    %thinned = 20 drops of thinner / (20 drops of thinner + 20 drops of paint) = 20 / 40 = 50% thinned

    2) % as a function of paint used. You start with 20 drops of paint. You add 20 drops of thinner. Therefore the ratio is calculated as:
    % thinned = (drops of thinner / (drops of paint)
    % thinned = 20 drops of thinner / 20 drops of paint = 20/20 = 100% thinned

    I used to use definition #2. After playing around with the airbrushes I now use definition #1. My question is, generally what definition do you all use when you state % thinned? #1 really makes more sense to me now.
     
  2. stona

    stona Well-Known Member

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    I always use a ratio. I typically thin my enamels about 50:50 paint to thinners and adjust if needed. 50:50 is surely self explanatory, in your system that would be 5 drops of paint to 5 drops of thinners. That is also a 50% dilution, not 100%.
    Cheers
    Steve
     
  3. Airframes

    Airframes Benevolens Magister

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    Yep.
    A basic start point is normally 50/50 paint/thinner, or 50% thinning ratio For example, 20 drops paint, 20 drops thinner. (100% would be all thinner, no paint!).
    Depending on the type of paint, make, and colour (some colours have a heavier pigment content), then a thinning ratio of maybe 40/60 might be needed - that is 40% paint to 60% thinner, for example 40 drops of paint to 60 drops of thinner, or even higher thinner content.
     
  4. N4521U

    N4521U Well-Known Member

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    In the case of splitting the Loot. it's 70% for me, 30% for you.
    That's pretty easy for Me to understand eh?
     
  5. mikewint

    mikewint Well-Known Member

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    #5 mikewint, Feb 17, 2014
    Last edited: Feb 19, 2014
    I'm a "seat-of-the-pants" thinner. Consistancy of milk or thinner is my only guide. Stir and let it run off, add some drops of thinner and try again till it "looks right". Thick paint will clog the brush and give a splatter-type texture while too thin will tend to run if you are even a tad uneven in application. And, it's always easier to thin more than to try to thicken a thinned out paint
     
  6. Crimea_River

    Crimea_River Well-Known Member

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    With the guys. I use ratios not percents.
     
  7. dneid

    dneid Active Member

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    LMAO..... you guys still crack me the hell up.
     
  8. Wayne Little

    Wayne Little Well-Known Member

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    Yeah I like your logic Bill...so long as I'm not the 30%...:lol:
     
  9. DarrellC

    DarrellC Member

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    Have you tried the Vallejo Model Air? made for airbrushing, no thinning needed.
     
  10. mikewint

    mikewint Well-Known Member

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    As to using %, it's the same as drops. 7 drops of paint and 3 drops of thinner is 70% - 30%. As to the pre-thinned ready to airbrush I always look at that claim with a jaundiced eye. Perhaps when it was new and fresh but how long has that been? How long sittting on the shelf? No seal is perfect so the most volatile components go first.
    Paint is just too individual to make specific "rules". Like milk or thinner.... By guess and by golly
     
  11. destrozas

    destrozas Well-Known Member

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    this will be a dilemma until one day you will see that by eye you know that solution, and I'll forget these things, and you cared on how to get a color that you do not have and you have nothing more than a visual reference.
     
    • Bacon Bacon x 1
  12. Rogi

    Rogi Active Member

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    Totally agree with Sergio, he is on the mark. Some days you'll need a little less or more of something depending on the conditions for painting.

    If you have a good basic starting point, adjusting the paint to flow better is only a few drops here and there.
     
  13. stona

    stona Well-Known Member

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    Yep, very true. I thin almost totally by eye (for want of a better expression). I don't actually measure anything.

    Cheers

    Steve
     
  14. Wayne Little

    Wayne Little Well-Known Member

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    me neither....whack in some of each then adjust further as necessary...
     
  15. Airframes

    Airframes Benevolens Magister

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    yep, me too - highly technical, but very simple !
     
  16. mikewint

    mikewint Well-Known Member

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    When I have the paint viscosity where I think it should be I spray onto white paper to check flow rate and spray pattern. As I spray the model I will still spray the paper to check on flow/pattern and make any necessary adjustment on the paper. It's, in a sense, wasting paint but cheaper in the long run opposed to a screwed up paint job
     
  17. Airframes

    Airframes Benevolens Magister

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    Yep, I always do a quick spray test onto the paper-covered bench first - never do first spray onto the model itself.
     
  18. destrozas

    destrozas Well-Known Member

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    the performance of the paint on the paper is completely different than in the plastic and can give us a scare and even spoil the whole work, in my case I have or the cutting template (piece of plastic of plastruc 1mm) that made ​​him Hence the beginning of each bowl, so it behaves as paint, but good Gunze (normally with pinto), it's always the same behavior.

    Another issue is the air pressure to work, I remember a few years ago always worked on a lot of pressure 21 psi and more settled now after taking the job with the airbrush work 5.8psi, or even less
     
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