Finer Spray?

Practice!
You need a good double-action, internal mix airbrush, the paint at the right consistancy, the pressure that produces the least overspray, and the airbrush at about 2" away from the surface.
What airbrush are you using?

Mike

Mike nailed it. The key is getting things set the right way and then lots of practice.

You can also go the masking route. Cut out patterns for the areas to be masked, and use something to lift them off the surface slightly when spraying. Small rolls of tape, "Blue Tak", etc. will work fine for lifting them. The higher off the surface they are the more overspray they will allow underneath and the more "Blended" the line will look. I did that earlier this year on a P-40 and while it was a real chore to draw and cut all those patterns, the results did look pretty decent.

I use an aztek internal mix double action, and I can't get lines that are too fine, but i can get to around 1/6 of an inch. I could get finer I'm sure but I lack the tan fine line nozzle, and I also lacka regulator for my compressor. With those two items I think I could manage some fine lines, but I'm not sure...

Or mebbe it just has to do with the fact that my airbrush is an aztek... lol

QUOTE: Or mebbe it just has to do with the fact that my airbrush is an aztek... lol

No, I don't think so. There are some very good modelers around here who get excellent results from the Azteks. Unfortunately they appear to be in the minority.

An airbrush is just a tool. As with any other tool, the quality of the work it produces is mostly dependant on the hand that holds it. Which explains why my paint work isn't as good as it should be

While I agree that it is not nessessarily the airbrush, it is your preparation. However, with regard to the Aztek, I had excellent results with the Tan nozzle and the Red nozzle for enamels. I was having the same issue as you are back then, and I was itching to complete the project using the Aztek. My formula for fine lines on 1/72nd to 1/48 scales using the Aztek was with the Tan nozzle, a 1:1 paint mix, approx. 10 to 15 psi on the compressor, spraying at a distance from the models surface of 1/2inch. I must confess though, my Aztek kept failing, I had replaced countless nozzles, and the long term cost of such maintainece just wasn't economical. I had the airbrushing skills onboard very well, however; after upgrading to my Iwata Eclipse (HP-C/ .3mm nozzle), my models began to win awards for their finish and over-all appearance. This isn't overly important to some, but in my case, the airbrush upgrade made all the difference.

Currently I use a Vega 2000 airbrush, using a fine tip and needle. This setup is really good but I still can't get some fine lines on my 1/72 aircraft. I've been thinking about getting an Iwata HP-CS ro HP-CPlus which sound like some really good quality airbrushes ,does any one have any thoughts on an airbrush that can give me a super fine spray line for 1/72 aircraft?

Sadly there really isnt a AB that will magically spray a fine line. Even the "best" AB will still spray a big fat line if the paint + thinner + air pressure isnt properly adjusted. Believe me if there was a magic AB Id own it but once again its just a tool and requires lots of practice and a skilled hand. My current AB's are Badger 100 gravity fed and 200 gravity fed.

QUOTE: does any one have any thoughts on an airbrush that can give me a super fine spray line for 1/72 aircraft?

The problem is that most of the airbrushes capable of super-fine illustration-quality lines will not allow paint pigments through the nozzle. The pigment is just too big since they were designed to spray ink.

I have seen some magnificent airbrush work in the pictures on this forum, and I'm here to tell you: It ain't the airbrush, it's the guy behind it. You have to have good quality tools, but the results are based on the hand holding the tool. If you want ultra-fine lines, everything has to be adjusted exactly right, and you have to do everything exactly right. Your hand has to stay in exactly the same relationship while painting (no deviation right or left, up or down). Your hand has to move at the same constant speed. You have to be able to adjust the paint flow on-the-fly to keep the density exactly the same. I'll be the first to admit that I can't do it, and I respect those who can.

No offense intended at all, perhaps your abilities are on this par. It's just that many people tend to blame their airbrush when their problems are not necessarily in that area.