airbrush not spraying with needle cap off?

[jds]

Hi All...
I’m new to airbrushing and just purchased a compressor and two air brushes the first is Air Brush Kit (AMA-208)

• Feed Type: Gravity type
• Nozzle Diameter: 0.2 & 0.3mm
• Cup Capacity: 2cc
• Working Pressure: 15-50psi
• Double Action Trigger

And the second is Air Brush Kit (AMA-128P)

• Body Length: 150mm
• Nozzle Diameter: 0.35mm & 0.5mm
• Glass jar: 22cc
• Push button control
• Includes 1 spanner
• Feed Type: Bottom

And after reading the thread on Help with I went and tried my two brushes to see if they also work with the needle cap off but they do not spray paint only air when I put the cap back on they work ok and the pressure on the compressor gage reads about 25psi with the trigger pushed but when I remove the cap and only the cap the pressure drops to almost 0psi with the trigger pushed and only air put no paint is sprayed any help will be much appreciated.
The compressor is an AS18-2

 

[Madbrush]

I f the photo you put up is is what you mean by taking the caps off, the back end of the 2 caps are the nozzle caps, you need to take a good look at these to see if they are in 2 pieces, they should be and neither will work without the back piece attached, the top one is definitely 2 pieces, I can see the joint, with this one take the crown shaped piece off and reattach the back piece, it will work, the bottom one looks like it's one piece so the whole thing needs to remain in place, the bottom pistol due to the bigger tip size is intended for spraying larger surfaces, so there is no need to remove the crown on this one.

Without the back end of either attached your only losing air.

Quick tip, before you replace the nozzle caps,, either take the needle out or pull the trigger all the way back to avoid bending the needle tip.

Hope this helps.

 

[jds]

Thanks for your quick response, upon closer inspection it appears you are correct and the tip in the top photo is in two parts
Many thanks for your assistance

 

[Stranger375]

Hi jds,
As Madbrush said, from your upper gun you only take off the crown on top cause thats the needle cap. I also have a gun like your other one
and there is no needle cap, the needle cap and air cap are one piece there so it wont work with that one. And pull the needle back as Madbrush
told you when you put them back on, so you dont bend the needle accidently.

 

[Madbrush]

Thanks for your quick response, upon closer inspection it appears you are correct and the tip in the top photo is in two parts
Many thanks for your assistance

Your welcome, and if there is anything your not sure of, ask here first before trying, we'll make sure your new hobby doesn't become a headache.

 

[Thomas Barber]

The cap that fits around the nozzle it self is to direct the air flow over the tip of the nozzle. This makes the air pressure at the the nozzle tip lower so the paint is pulled out from the nozzle its self. With out this cap the air isn't directed so it won't. However, the end cap its to protect the needle and it will work without this. Im not sure if i answered your question but its what i know.