Help needed....

[BarryW]

very new to airbrushing and there may be an obvious answer or I just might have this wrong!!! Please advise..

My compressor is set to have a switch-off at 4 bar automatically and to switch back on when it drops to 3 bar.

It is an AS186 being used with a BD-133 airbrush as per link, bought as a set.

http://www.airbrush-pro.co.uk/index1.html

I have tried to do fine lines but with little or no success. According to the 'blurb' the airbrush is capable of this.

I am wondering if the pressure is too high. I have read that the pressure should be at 1 to 1.5 bar. I have found the pressure regulator but I cannot detect it doing anything! Any help. tips or suggestions would be welcome.

 

[stona]

Hi Barry and welcome to the mad house.

4 bar sounds like the maximum pressure that your compressor can deliver and that is much too high for airbrushing. The 1-1.5 bar range you mentioned is about right though you will have to play around to find what works with your particular set up. You say you have found the regulator and presumably a pressure gauge.I don't know which regulator is fitted to your compressor but typically there will be a knob on top that can be turned to adjust the output pressure. You may find that you have to lift the knob to unlock it before turning. I can only give a general opinion,hopefully someone with a similar compressor will be along soon.

Your airbrush has a 0.3mm nozzle so with the correct paint/pressure set up you should be able to achieve fine lines and detail. It takes a bit of practice!

I read your introduction and can confirm that the older we get the smaller those parts get,particularly photo etch!I speak as a man who recently lost a harness buckle only to find it superglued under a finger nail a couple of days later.

The Ju88 is a good model but doesn't quite fall together. I can't imagine needing any more interior detail,the only extras it needs are really the external bomb racks. The big Tamiya Spitfire is quite simply the best kit I've built.

Cheers

Steve

 

[Gomer Pyle]

Hi Barry

There are many variables in doing fine lines. Make sure your paint-mix has the right viscosity (generally referred to as the consistency of milk) Personally I prefer a thinner mix or ink for doing fine lines, also acrylic and lacquer based paints have a higher tendency to clog the nozzle when doing fine lines (low paint flow, which leads to splatters and wider spay patterns). That can be helped using more thinners, retarder or a combo of both – it’s a trial and error sort of thing.

Secondly; as you have already found out 1-1½ bar would be a good pressure setting (I often go lower, but then again I like using a thinner mix). It worries me to hear, that nothing happens when you turn the pressure regulator (check if it's one of those that needs to be lifted or pushed before you turn it, like a safety-cap sort of thing). Typically there should be a slight hissing sound when you regulate the pressure in significant steps and it should be immediately apparent on the pressure-gauge. Ensure that the pressure-gauge is located "downstream" of the airflow from the regulator, otherwise you might have a defect on your hands.

Then there is the paint flow, controlled by pulling the trigger back towards the rear of the AB.

It looks as if your particular AB has a paint limiter (the knob all the way at the rear) Try setting this in the closed position, effectively locking the triggers rearward movement. Push the trigger for air and gently pull at it while turning the paint limiter slowly open. When paint starts to flow it should be in a good position for fine lines.

The finer lines you need, the more you have to close the distance between the nozzle and subject. Some people unscrew the nozzle protection ring at the end of the AB, claiming to get an even finer airflow. I never tried this fearing to accidently touch the subject with the needle.

I’m not familiar with your particular AB, but with a 0,3 mm nozzle it should be able to do lines like a lead pencil that could do with some sharpening (somewhere around 1-2 mm). If you have a magnifying glass or a low-powered microscope you should check the needle. It can sometimes have an unnoticeable bend at the tip, causing lots of turbulence and hence wider spray patterns.

Good luck and happy spraying, I remember the steep learning curve when I got my AB and fine lines were one of my first hurdles – it is great fun when, it all starts working with you, rather than against you

/Daniel

 

[lemoff]

I have a similar problem with my setup (same compressor) but been a little too busy to have a proper play.

 

[BarryW]

Thanks for the tips everyone. Still puzzled by how the pressure should be set, I will explain what I have tried to do so far.

I have tried turning on the compressor and allowing pressure to build up to the point it switches off (4 bar). I then turned the regulator anti-clockwise (having pulled it out) - there being no indication anywhere about what direction it should be turned to increase or reduce pressure. I then pressed the button on the airbrush and allowed the pressure to drop to the point that the compressor switches back on (3 bar) and at which point the air pressure built back up to the 4 bar showing nothing had changed. So I tried it the other way, turning it clockwise instead - again no change.

I suspect it is me not the machine and I am puzzled about how I get to the 1.5 bar pressure. I assume that I might not have turned the knob enough but I thought I might get some noticeable change on the gauge so I could work out the direction to turn the regulator and work back from there. I did not carry on turning it more in either direction because not knowing what I was doing I did not want to risk damaging anything. I am amazed that there are no instructions of any kind with the compressor to show how this is done!!

Puzzled!!!!

 

[stona]

My regulator has to be turned anti-clockwise to reduce the pressure which is counter intuitive.

I suggest running up the compressor and then ,whilst shooting air through your brush give the regulator a good couple of turns anti-clockwise and see what happens.If there is no change wind it back the other way. You didn't say how much you had turned it above but they usually have quite a bit of movement.

As long as you don't force anything you won't break anything!

If you still have no change then there must be some other issue.

Cheers

Steve

 

[tecdes]

Barry just a thought. Are you sure you pull the regulator knob up. Wonder if it may need pressing down ?

Laurie

 

[BarryW]

Thanks Stona - I will try what you say later.

tecdes - to turn it I had to pull it up (would not go down) and then pushed it down which I assume then locks it.

 

[stona]

tecdes - to turn it I had to pull it up (would not go down) and then pushed it down which I assume then locks it.

That sounds right.

Steve

 

[lemoff]

I have just tried that with mine (same model) and i have tried to turn down the pressure. It seems that the knob just changes the pressure that the compressor stops as. After much turning down, it now stops at 3 bar instead of 4. It does not appear to adjust the pressure that it outputs as. Will upload a pic in a sec to confirm the knob i am talking about :D

Lift and turn clockwise seems to increase the pressure that it stops at.

View attachment 31499

Edit - added the pic.

View attachment 36535

 

[BarryW]

Well that worked for me. After a fair bit of trial and error it now stops at about 1.5 bar and re-starts when it drops to 1.2 bar. Not actually done any painting yet with it, not had the time, but will report on the results when I get a chance which may not be for a day or two. Anti-clockwise does reduce the pressure but you have to turn it a lot to get an effect.

Thanks again Stona