The valve feeding air into the brush wil not pass any air into the unit when the trigger is depressed.
The unit has not been used in decades.
I’be completely disassembled the unit including taking the air valve apart and can see no faults or obstructions.
All passages pass air except the air valve itself. Even manually depressing the valve when removed from the unit with air can hooked up will not pass air. The air pressure is reaching the air valve. Loosening the hose releases air.
On first operating the brush with paint thinner only in the jar I got a short spray and then nothing.
A friend gave me his Iwata Eclipse to try and fix. It was seized shut tight, so I took it apart and soaked it in Laquer thinner for an hour and it sprayed like new.
I’m not at all familiar with Badger airbrushes, but my Pasche airbrush has an adjustment on the air inlet valve, which allows regulation of the air input, depending on the type or characteristics of whatever paint you might be using.
It’s easily accessible where the airhose connects to the airbrush, and the adjustment can be made with a suitably-sized slot-type screwdriver - turn it in (I think) to close-off the air, turn it out, to allow more air to pass.
I don’t recall needing to adjust it more than a couple of times over the last 40-some years I’ve been using it.
Inside the valve body there’s a spring loaded rod that has a dome shaped valve at the bottom end, with an o ring seal. The upper pointed end of this rod valve fits into a depression in the base of the trigger. When you press the trigger it depresses the valve against the spring which should allow air to pass by the o ring, but it doesn’t.
Lastspickmike, I am sure you may know all this, but just in case you are missing something.
I am looking at the removed “valve assembly #50-036” from the air brush shell.
Unscrew the ‘‘brass plug/valve screw #50-015’’ with a hex/allen wrench/key (be sure you can see though that hex opening when it is removed) then out will come the ‘‘plunger spring #50-020’’ followed by the ‘‘plunger & O-ring #50-014’’.
How it works is, the spring pushes the plunger and O-ring back (towards the air brush shell) into a recess area in the valve casing and closes off the air flow.
When you push the plunger into the body of the ‘‘valve casing #50-013’’ the ''O-ring #50-0141" never loosely floating, always attached to the plunger, goes in to the hollowed out/enlarged area of the valve casing and the air then passes around the O-ring and out the two holes opposite of each other in the side of the valve casing. Some air will also escape around the plunger’s shaft.
Oh and those three little black lines are dog hairs.
In the picture below, the larger O-ring on the right is from a nozzle of a BIC lighter. Yes I save stuff. To remove or install o-rings this tiny, I use a Dental pick, which I’m sure most of you have in your arsenal of tools.
Yes, the failure mode seems to be swelling of the o ring which eliminates any clearance between the o ring and the inside diameter of the fitting passing the air.
O rings seal by the Venturi effect so in order to work there has to be minimal clearance between the outside circumference of the o ring and the inside circumference of the valve body. A piston ring in an internal combustion engine exploits a similar effect, pressure gets behind the piston ring in the land cut into the piston and there being no corresponding pressure on the face of the ring it is pressed against the cylinder wall. O rings seal in similar fashion, the higher the pressure the tighter the sealing force.
