Model Train Forum banner

Air brush problem.

5.6K views 23 replies 14 participants last post by  traction fan  
#1 ·
I haven't used an airbrush in years. Best I recall, I had
no difficulty at all with the one I had. I used it with
a propellent can.

Bought a new cheapo with propellent can. Read the
instructions and followed them. Got my model
all masked and hooked up the air brush. I could get a puff
of air, then nothing. Tried various adjustments. No
improvement.

Then I noticed that the propellant can was very cold. That
indicated to me it was 'leaking' tho I could not hear it or
feel any air escaping.

Anybody got an idea of what I did wrong?

Don
 
#2 ·
Don,
The best thing I could recommend is get past the propellant cans and get a compressor, it will produce much better and consistent results due to less inconsistent pressures you'll find with propellants which can be affected by temp, humidity or both!
 
#4 ·
Use the soap bubble technique to find any leaks. A few drops of dishwashing liquid in a pint (or so) of water. Dribble the water over a suspect joint or area. If you have a leak, bubbles will slowly expand.
 
#5 ·
Guys

I have a small tire compressor but can't find the adapters to
connect the air brush.

This is the first attempt at painting a car in years. Don't think
it would be practical to buy another compressor for the few tiny
paint jobs I have.

The propellant can returned to normal temp last night. I'll give
it another try today. When I rock it I feel it is still charged.
Forgot all about the old 'bubble' leak test.
Gotta try it.

The can instructions say don't TILT the can after screwing on the
valve. I accidentally did that. I wonder if that got the propellant
in the valve and it froze.

If it doesn't work I'll get out the rattle cans.

Don
 
#6 ·
From your post you say you have a small tire compressor. As far as adapters, try looking at Home Depot or Lowes at their brass fittings. You may be able to come up with what you need, and it won't cost you an arm and leg for price. Just a thought.
 
#7 ·
I'll check out what adapters HD and Lowes might have. The
'tire' hose does not seem to use a standard connection to
the pump. Would seem to need an adapter from the tire
valve connection.

What I found with further can testing, The air brush valve body
does not seal properly onto the can. When I 'turn on'
the gas, there is serious leaking from the around the fitting. There
is a gasket in the air brush valve so don't know why
the leak. There is no leak in the air brush hose or
fittings.

Went ahead with paint brush in hand, did interior and roof. Want to test rattle can paint
for compatibility with plastic.

Don
 
#8 ·
Don,

You know I call 'em like I see 'em. What you did wrong was to try to use the canned propellant. I'll give you the same advice someone gave me when I was thinking of doing the same thing: sometimes, you need to pony up and pay more for a quality solution. This is one of those times.

Don't kill yourself, though. My first airbrush was the intro kit from Testors. I upgraded the airbrush after a couple of years, and used the compressor with a higher end Aztek airbrush for another six or seven. I bought it at Michaels using the 50% off one item coupon, and it cost me something like $70. You may be able to find just the compressor cheap.
 
#10 ·
Latest update on this sad saga.

Realized that using the tire air pump through
the adapter would need a pressure regulator
since there is no tank and pressure cutoff
switch for the pump. Checked Home Depot.
They have pressure gauges, but no regulator
for it. Will ponder more.

CTValley

I was hoping to cheap it out since I so seldom
have need of an airbrush. I had this one
nicely detailed CONRAIL caboose. Way wrong
for my 50s 60s era. Wanted to repaint it
to Santa Fe colors. Brake fluid did a good job
cleaning it. Now, trying to get the red paint
on it nice and smooth. Will ponder that also.
But, now I have wasted $ on the can, and no
paint is on the caboose. I may take up knitting.

Appreciate the thinking and suggestions.

Don
 
#11 ·
I have no idea what the problem is with the leaking at the can valve. But I'm positive that when you tilted the can, you did get some liquid in the assembly and it froze. That would well explain the puffs you got, as a bit of it thawed and then refroze when you hit the button and released the pressure. Good luck.
 
#17 ·
I have that same compressor. I don't even own an airbrush (yet), but when I do I plan to use this for it. It's rather noisy, though, so it may be in the room next door with the door mostly closed!;)
 
#13 ·
Hey, guys. First of all, PM's on this site are temporarily down. Secondly, this thread had been inactive for 6 weeks before you resurrected it. Probably not worth everyone's time unless the OP brings it back.
 
#15 ·
You're never too late when you have a good suggestion.
That guy is good.

I still have a loco DCC/motor upgrade and shell repaint job that I'm
doing for a friend and have not yet gone back to the air brush.

I had good success with the Tamiya can spray, but have had
difficulty with the spray quality on another brand.

I'll be back when I get something to show off.

Don
 
#16 ·
You're never too late when you have a good suggestion.
That guy is good.

I still have a loco DCC/motor upgrade and shell repaint job that I'm
doing for a friend and have not yet gone back to the air brush.

Don
Yes, it's an interesting site, full of informative stuff. I'm in the market for an airbrush myself so it was very useful. He's a really nice guy too, I wrote to him complimenting him on the site and he replied with a very nice email.
 
#18 ·
Building an air tank system is best done buying a complete unit, Harbor Freight has good deals, you can get a setup for around $40. I tried to do it piece-meal, getting a compressor here, a tank there, regulators elsewhere. Once it was all put together I realized it did not have an 'unloader' on the switch, so the compressor stalled when trying to start against anything but an almost empty tank. Lesson learned.
At the thrift store I came across a 'nebulizer' compressor for home health uses. It puts out nice steady low pressure, seems just right for air-brushing. All I have to get now is some 1/4" tubing for the hookup. I don't know if fish tank compressors have enough pressure and volume for air-brushing, but would like to try it, they are nice and quiet. An air brush just doesn't take much volume.
 
#19 ·
Most airbrushes call for between 20 and 40 psi, which is probably much higher than any aquarium or home health application. You don't need the volume, but you do need some "oomph" behind it.
 
#20 ·
I used these a long time ago and finally went to an airbrush compressor.
An old trick with the can is to put it in a pot of warm water. " Not on the stove" !!
Just warm water will lower the coolant/ propellant temp to allow it to pressurize your airbrush. Also, check that the can propellant valve is clear and not blocked.
 
#21 ·
Air brush paint booth with clear plastic & duct tape

:Hobby compressors are easy to find used at basement bargain prices.I went with a single
action badger airbrush. Really helps in modeling, I configured my own paint both out of
clear plastic mounted on a frame and vented out of the clothes dryer vent. Simple yet
effective. A venting fan is needed though.:smokin:Regard's,tr1
 
#22 ·
More than just a venting fan, it needs to be a sealed or brushless unit, like one designed for a bathroom or stove, rather than any old fan unit.

Also, bargain basement compressors are often just that, and you might be better of spending a little more for a quality model.
 
#23 ·
special venting fans are needed,Iagree.

I've had very good results with my setup. Mostly used forWWII aircraft sporting cool
camoflodge designs. The airbrush is indispensable in this regard. It also comes in handy, I'm told, or assume, for weathering. Although, I have not gotten that far yet. Still to many other things to concentrate on. I guess, you have to learn how to prioritize.:)
 
#24 · (Edited)
Cold Propelent can

DonR.

Reading through this thread, I don't see any mention of why the can got cold. When the propellent gas is released from the can, it is normal for the can to feel very cold. This would have happened even if you did not have a leak in the system. The leak just speeded up the cooling by letting out a lot of propellent in a hurry.
I used propellent cans successfully with my first airbrush.( the brush came with two cans) They painted OK, but they cost enough to make the compressor worthwhile for me , as I do a lot of painting. If your paint job is a one shot, perhaps you will be OK with the cans, once you are able to fix the leak.
I don't know how much pressure your tire compressor puts out, but unless it's over 30psi, you could get by without a regulator. Regulators are used to tame the output of high pressure compressors down to something the
airbrush can handle.
If you think you might be doing more than one or two paint jobs, I agree with everyone else. Get a compressor.
Harborfreighttools.com has several small compressors available relatively cheap.

Good luck;
Traction Fan