newbie airbrushing finish question

Mr. Dave -

More info is needed to answer clearly, are you describing a set of wings being painted individually but at the same time, or two different painting sessions?

If it's two separate wings in one session, a grainy finish could be caused by one wing getting overspray from the first wing, as the paint was being applied at start of session.

If you're describing two different model painting sessions, and the surface was well prepped and cleaned prior, then there could be a few culprits. One being an improper thinning ratio, or another, the airbrush distance from the model surface being too far. In that case, the paint particles are partially drying on the way to the surface, then settling on as rough and gritty dots.

And sometimes, no matter how careful we try to be, dust particles can just somehow get into a fresh finish. A Shuckey Darn moment.

Another possibility could be too much pressure, that can can get paint blowing all over like a dust storm. I airbrush enamel, lacquers and acrylics, my most common pressure is 15-18 psi using a variety of AB's, the Extreme being one of them.

The usual distance from the AB tip to model surface, for me, is about 1-2 inches. All depending on the paint, tip size and surface area to be covered.

Lots of great airbrushers here, hopefully we'll hear from them too.

Patrick 

GM Patrick.

Thank you for your suggestions, especially given that I did not provide nearly enough info.

I did have two separate painting sessions.  From what you suggested, I probably was not close enough.  I kept the pressure at 20 psi which I might lower the next time.  I think I made a big mistake in thinning with mineral spirits instead of lacquer thinner.

I am finding that this is much more of an art than science.  Thanks for taking your time.

I am assuming you meant isopropyl alcohol and water mix.  As long as that solution was completely dry, you should be okay.  It does not leave any residue.

The only paint that must be thinned with lacquer thinner is real lacquer.  Most of us do not use lacquer thinner for acrylics or enamels.  What paint are you using?

I suspect the problem was a slight change in airbrushing technique is the problem.  Slight changes in distance or paint flow, or thinning ratio, or a number of other things, can have a big effect on the appearance.

In addition to the good advice by Patrick and Don, might I add.......

My 2 cents might be to stick with manufacturers own* thinners until you learn some airbrushing basics. For example, for MM enamels, use MM enamel thinner.

This elimates at least one variable from the mix (pun not intended).

*edited for clarity, thanks to Ernie's post below.

Yep. I cleaned with isopropyl wipes.  I'm using MM gloss and flat enamels.  I have just started out developing my technique.  Thanks for your insight.

Dave -

Some airbrushers use lacquer reducer for thinning regularly, with good results. One advantage of that is faster drying time, with good "bite" for more positive adhesion. But LT is not compatible for spraying over a previously painted enamel finish, it can wrinkle the enamel by being too agressive and attacking the finish.

LT is my most used product for cleaning the airbrush after use. For MM enamel I thin with their own Universal Enamel Thinner, 1/2 pint red can, product number 8824, or major brand enamel thinner. MM thinner is pricey for the amount, so for much of my enamel painting I thin with a major brand, (Du Pont.) MM thinner is about $10 bucks for the 1/2 pint can, the other is about $7.00 for a quart.

One major consideration for painting is good light. In order to see how the paint is laying down and flowing from one pass into the next, good strong light at a slight angle to the surface will work well. One pass should just "melt" into the previous, otherwise you have either a gritty or pebbly surface.

Best practice is to get a good supply of paint and thinner, some plastic scrap to paint on, then just spray away. Using good light will be an advantage, varying the distance from the object, adjusting pressure and thinning ratios will all demonstrate what works best, and what doesn't work at all.

When I got started over 50 years ago I had frustrations, over just what you have described. About to give up I thought ya' know, others can do this, I can too. So I sourced a lot of scrap material for practicing on, and spent long periods just doing that. When you see that your work is improving, the motivation to continue practicing is what makes the hobby so enjoyable.

I quit trying to paint models until I felt my work was worthy of actually painting one, several sessions of that intense practicing paid off and I had the confidence to go about finishing models. Been enjoying the hobby all the more for decades now, but keep in mind that airbrushing is not quite as easy as one might think when getting started.

Plenty of youtube sites about airbrushing are worth a visit, I've learned many things new to me from them, and from the experienced guys here on the forum. If you have not yet visited "Don Wheeler's Airbrush Website," I heartily recommend it. You'll find just about everything there is about airbrushing, including cleaning and adjustments. So well worth the time.

I'll bet next time we hear from you, you will have some success stories about your own work to tell us. I'll look forward to it.

Patrick 

Dave, I'm using the same airbrush you are. I just upgraded from a Badger 200-20, single action. I seldom set the output pressure on my compressor in excess of 15 lbs and that's usually only when I am cleaning out color from the brush. With 20 lbs of pressure, you are probably holding the brush some distance from your model and the paint is drying before it gets to the model. I use Model Master enamels and Alclad metalics mostly and they shoot very well at 9 lbs to 12 lbs, 15 lbs max, of output pressure. My brush tip is seldom more than three inches from the model I am painting. Lately, with the new Patriot 105, I have been trying to stay one to two inches from the model. If I am shooting from a distance os six inches or more it is because I am misting the model with Pledge to seal the paint.

Get yourself a 2 liter soda bottle and practice with your airbrush at lower output pressures and see what kind of results you get.

I'm pretty new at this too. Fortunately I have an excellent mentor helping me develop my technique.

Don Stauffer

 

I suspect the problem was a slight change in airbrushing technique is the problem.  Slight changes in distance or paint flow, or thinning ratio, or a number of other things, can have a big effect on the appearance.

  

Don hit it head on. You did something different and I suspect thinning ratio and distance.

Do yourself a favor and stick as previously mentioned to the manufacture's products. I also use MM enamels and I only thin with Testor's Thinner (in the red can from HL). Get this thinner and use the 40% disc. coupon. I also previously used generic thinner but discovered the paint would not dissolve completely as it does with the Testor's thinner.

I do use LT to clean the AB and it does a fantastic job at removing dried paint.

Thank you all for your interest in helping me with this issue.  In an attempt to eliminate one of the variables, I ordered Vallejo's airbrush ready paint.  Having been away from this side of the hobby, it's really exciting to see so many new products that make the task go so much smoother.

Thank you all very much.

Hopefully I'll figure out how to post images without having to pay for another service.  I already use jAlbum to post my photographic albums on line in addition to my personal website.

MrDave

Thank you all for your interest in helping me with this issue.  In an attempt to eliminate one of the variables, I ordered Vallejo's airbrush ready paint.  Having been away from this side of the hobby, it's really exciting to see so many new products that make the task go so much smoother.

Thank you all very much.

Hopefully I'll figure out how to post images without having to pay for another service.  I already use jAlbum to post my photographic albums on line in addition to my personal website.

 

You are welcome but a few words about Vallejo since you are an enamel paint user like me. I also got some Vallejo Air paints to experiment with since the MM military FS line is being discontinued.

Vallejo says  it can be sprayed out of the bottle, you will get better performance if you thin it with a couple of drops of their thinner and add a drop of their flow improver. The retarder will help keep tip dry down and slow down the drying time.

Still not quite the same performance I get from my enamels but I had positve results during my experimentation sessions. You can use regular LT to clean out the ab.  

Well, for the "for what it's worth" category, I bought the Badger primer and turned up the regulator pressure to 25psi. I think it turned out very nicely.  It's still drying but so far I really like the finish.  I was able to spray the primer with no thinner.

Next I will test out the Vallejo Air and MM enamel at the 25psi.  Then I'll drop it to 20.

I really appreciate all your help and suggestions.  Your a good bunch.  Think I'll stick around.