Is this a problem?

[Bari]

I have been given an double action airbrush and compressor as a retirement gift. All seems to be fine and i have been practising away on plastic bottles etc but I have noticed that there is a slight flow of air all the time from the nozzle, is this normal/ok. I haven't taken it to bits to see if there is a problem mainly because I won't know what to look at. I Also a friend has given me a single action (bottle underneath) brush but the nozzle appears to be blocked as I can't get it to work. I have done all the things I could think of ie tube in bottle not blocked or resting on the bottom of the bottle. I've adjusted the bottle nozzle up and down. I've tried to put a very thin copper wire through the nozzle but it hits something solid, is there a little plate in there or should it be a straight through passage? I've got it soaking in a container of white spirit at the moment. He used it to paint motorcycle tanks and Helmets.

 

[Ian M]

OK the double action one first: The needle is not seating right down in the nozzle, It might well be that the needle just needs loosening at the lock nut and re-positioning. Just lose the nut at the back of the needle holder and draw the needle out a little. Then give a blast of cleaner through the nozzle, this it just to make sure there is nothing sitting in the nozzle. Then if all is well, GENTLY slide the needle back in place. DO NOT push it hard as you risk splitting the nozzle. This should seat the needle correctly.

The Single action one: Sounds like there is paint in the nozzle that delivers the paint. Which is what I assume you are finding to be blocked. I am not sure that white spirit is "hot enough" if he the previous owner has been spraying car paints with it. Go to the hardware store and buy some cellulose thinners and let it soak in that for a while.

What make is the double action...

Ian M

 

[dubster72]

There shouldn't be any airflow when the compressor is off, so maybe a valve is not closing properly. Only a strip-down will reveal the problem area or maybe test it with another AB you know is working ok.

As for the single action, inside the nozzle is the needle which is probably what the wire is hitting. Again, strip it down & clean it thoroughly. There's some decent images of AB cutaways on the Badger site.

Patrick

 

[stona]

On a double action brush there shouldn't be any air flow until you depress the trigger. You didn't say what airbrush you have and they do vary slightly though the principals are the same. Normally the trigger will act on a sprung plunger which opens a valve to allow the air to flow. This may seem obvious but if,with the airbrush connected to your air supply, you gently pull UP on the trigger does the air flow stop?

For the second one it does sound like something is blocked. Bearing in mind the sort of paints I suspect your friend used a good soak in cellulose thinners rather than white spirits might be an option.

Cheers

Steve

 

[Bari]

Hi, thanks for the replies, It has been confirmed that cellulose paints were used and some of the relevant thinners is on the way. I thought I would use the single action just for large areas and klear.

The double action is I think a generic chinese one the only model number I can find is AB725. However I have have taken the back off it and checked the needle and given things a clean. The needle clamp ? was a bit loose so have finger tightened everything. The air leakage is still there but not so great and it does stop if i pull up on the trigger although no movement of the trigger is felt. Having had a look at the schematic of the parts in the trigger area I'm not sure whether to take it to bits or back to the shop for a replacement.

Have read a bit more and have had play with the adjustment of the air piston but its made no difference, there is no fluid coming out unless i pull back on the trigger its just that when the trigger is in the at rest position there is a continual stream of air coming from the nozzle. i can only assume that there is perhaps an O ring missing or damaged

 

[sprayman]

Did you get a nozzle spanner with the kit, if so remove the nozzle cap....

Then tighten the nozzle with the nozzle spanner....

If this fails to stop the leaking air, I would think either the nozzle has no seal or the needle may have a slight kink or bend.....and in rare occasions the needle may be the wrong size for the gun.

Hope you get it sorted.

Ray

 

[Bari]

Thanks for that, I have tried it but its just the same, in fact the quantity of air escaping seems to be increasing each time I check something. So it's back to the shop at the weekend and they can change it.

 

[Bari]

OK, its now been sorted, After spending quite a time in the shop with a very knowledgeable chap it was eventually worked out that when the needle was in place it depressed the trigger slightly causing air to flow. We can only think that the slot in the trigger was not milled out properly. Any way the brush was replaced (and tested before leaving the shop) and all is now well. Thanks for all the suggestions.