Paint/Thinning Question....

[dneid]

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.

 

[stona]

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

 

[Airframes]

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.

 

[N4521U]

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

 

[mikewint]

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

 

[Crimea_River]

With the guys. I use ratios not percents.

 

[dneid]

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

LMAO..... you guys still crack me the hell up.

 

[Wayne Little]

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

 

[DarrellC]

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

 

[mikewint]

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

 

[destrozas]

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.

 

[Rogi]

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.

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.

 

[stona]

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.

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

Cheers

Steve

 

[Wayne Little]

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

 

[Airframes]

yep, me too - highly technical, but very simple !

 

[mikewint]

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

 

[Airframes]

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

 

[destrozas]

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

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