I’m using a Paasche Type VL airbrush and an Airmaster Plus compressor. Lately, the paint has been going down as small grits and lumps - very grainy. I checked the FSM airbrushing article (March 2002) and it gave 4 causes: (1) paint not thinned enough, (2) airbrush too far away, (3) pigment not dissolving in the thinner, (4) too much air pressure. (I’ve been using airbrushes for over 25 years.)
(1) I’ve thinned the paint to different degrees and it doesn;t make any difference, (2) I know the airbrush is not too far away, (3) I’m sure the pigment is dissolving in the thinner, (4) I don’t think I using too much pressure.
If anything, it seems like the air pressure directly from the compressor is low. I don’t have a guage to check it, but I have a gut feeling it’s too low.
I’ve tried different pressures, but it doesn’t help. In fact, when I lower the pressure, flow almost stops competely. I’m beginning to think that the compressor is no longer putting out enough pressure. Would that cause the gritty effect? If so, what can I do? I don’t really want to buy a new compressor right now.
I would suggest getting an air pressure regulater (with a moisture trap), filtering your paint (through panythose) and making sure your paint is the right consistancy.
Low air pressure can cause spattering as the paint doesn’t quite go aerosol…I’m not sure the effects of high line pressure but I spray between 18-23 with good results. A regulater and moisture trap would ensure air pressur consitancy and avoid water droplets mixing with paint (which spatter and ruin paint)
Filtering you paint is a precaution, but helps make sure the consistancy is correct and removes clumps! How old is your paint??? old paint has usually has more pigment then solvent and sometimes requires more thinner than you would usually use.
I’m no pro, but these are all tips I’ve gathered over the years (I’ve only been at this on/off for about 5 yrs.)
Hope it helps…I love the hobby and can’t wait to finish up my latest project…I’m on the last leg
Good luck, happy modeling
James
A pressure regulator and moisture trap would be a definite must, i use a pressure between 12-15 psi
what pressure are you running through your brush ?
make sure your paint is mixed really good before spraying
Agree with prior posts. My first action would be to determine what pressure you are getting at the air-brush (likely it is too low). Sounds like that’s your concern also and with 25 years of experience, chances are your hunch is probably right.
Highly recommend getting a regulator, gauge, and moisture trap.
M.
I agree, I worked with air compressors and you should always
regulate and filter-dry the air before it gets to the end device.
Hey Russwalker - I’ve had the same problem and have come to the conclusion that the problem might be with the air supply - not necessarily moisture but contamination from a bad hose or the tank itself (rust), and I don’t know if a moisture trap would solve that problem.
But just make sure the airbrush is spanking clean inside and the paint is strained as well.
Something else I discovered is that the paint bottle I was using had a ball like assembly on the top that in itself could be disassembled. What I discovered inside was not good! Old pieces of pipe cleaner material from previous cleanings and other junk too! Now I only use the color cup for most of my painting.
What do you think about this?
I’m not familiear with your airbrush, but the needle could be dull or bent (if it has a needle that is). Also check for buildup and junk inside.