How does one achieve the mottled effect seen on many German WWII aircraft? By this I mean the circular splotches that run along the fuselage. I've tried using a small tip on my airbrush and lowering the pressure. When I get close, however, and give it a blast I usually get lines of paint spreading out from the spot, not the feathered effect I'm looking for. Should I be masking it somehow?

TIA
...Kevin

Take a paper index card and several diffent sized nails. Over a soft surface, like a cork tile, punch numerous holes in your card stock in a random pattern. Don't worry about the rough edges, that's what we want. Holding the card slightly away from the model, rough side down, shoot paint at the card. You should be left with feather edge splotches on your model. By varying the distance of the card and model, you can get different effects. Practice first on a suitable subject.

I found a easier way to get the mottled look..... EagleStrike (a decal mfg. company) has a stencil for 72, 48, and 32 scale german aircraft. http://www.aeromaster.com Check out the link

Thanks for the advice. I think I'll give the "free" method a try first and if that fails I'll purchase the masks. Do either of you vary the PSI or thinner ratio from what you normally use for the rest of the paint job?

Thanks
...Kevin

:-) Kevin
A subject close to my heart. Masking is OK and you can get very nice affects. I believe though that it's well worth mastering the art of free hand mottling. If you can do it nothing else will be a problem :-) The thing is you can do it. There is not a set formula, there are to many veriables for that. To form the mottle requires that you spray close to the model and form the patch gradually. To be able to do this first of all the paint has to be heavily thinned, 70-30, 80-20 or even 90-10! This allows you to build up the colour gradually. It also means that if you get close the air pressure will blast the mix everywhere. So the pressure has to be very low, 0.5 even 0.25 bar. There is no set pressure because it depends on how thin the paint is. If every thing is right then you should be able to get in close ( down to 5mm for small spots) and start the spray "in position" drawing the outline of the mottle, slowly, then gradually filling it in. When everything is right it will take a few passes to get the depth of colour that you want. It takes time but is more than worth it.
The only real way to do it is first of all want to, then practice with different paint thinner ratios and pressure settings until you understand what is required for your paint of choice. First of all mix a batch of paint and see how it performs at different pressure settings. There will be an optimum pressure for the mix. You will not be able to make a table of these settings because you will not be able to ever recreate them exactly (I know I've tried). Then add thinner to the mix and try another set of pressure settings, then again and again. You will then start to be able to understand what is required.
What I have outlined is actually the way I airbrush to achive pre-shading. I mix paint now without messuring quantities and 9 times out of 10 get it right first time. I use a Badger 200 single action airbrush, I used to use a jar but now I always use a side cup. I will be getting a gravity feed double action brush because I believe I have done all I can with the single action syphon brush. :-)
Do give it a go, it took me years to work this out, no internet when I started and remember it wont just happen you will get frustrated, but persevere because this is, in my mind, is the key to the ultimate airbrush control. Oh don't forget to practice sprying on the same medium as you models, ie plastic or primer coated plastic :-)
I look forward to the results, I have a few in the gallery, I think :-)
Mal

Mal, is right on. Check out my 109G6 in rivet review board. All of those mottles are done freehand, I dont use masks to get them. Masks are difficult to use for mottles because they look masked (bad - because the mottles were applied freehand in real life.

If you are getting "spidering" which is what you describe, then your paint is too thin and your PSI too high. You may also be too close. Practice on an old model as Mal said until you get the paint and psi to where you are comfortable.

Spidering = thin paint, too high PSI
Pebbling or spitting = thick paint or too low PSI

If you use enamels, start at 60% paint to 40% thinner and a PSI at about 20. See if that works and adjust from there. If you use an Aztek brush, start at about 25 PSI and go from there. I don't like acrylics so I am no expert there.

HTH,

Scott

Hmmm . . . I'll experiment both with and without a mask to see which one is easier and which produces the best effect for me. Holdfast, I was looking in the gallery and saw your Bf-110. That's the effect I'm looking for and, interestingly, is the same subject I have in mind for this camo attempt. Is that the Revellogram/ProModeler 1/48 kit?

...Kevin

:-) Yep, Kevin, It's the Revellogram/ProModeler 1/48 kit. It really isn't that difficult, just practice first. Expect not to get it right, at first, then adjust one thing at a time, ie air pressure. If that doesn't give you the disired results try something else, say thinning the paint more. If that doesn't do the trick then leave the paint as is and try adjusting the air pressure again. You will come up with what works for your airbrush and paint. :-) Let us know how you get on :-)
Mal