Yet another airbrush help thread (but this one isn't the same as all the others, honest!)

Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you:

No adverts like this in the forums anymore.
Times and dates in your local timezone.
Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance.
Email notifications for threads you want to watch closely.
Being a part of the oldest wargaming community on the net.

If you are already a member then feel free to login now.

**Azreal13**

My (Chinese knock off) airbrush is behaving in an odd manner that I've not encountered before.

I was running some Vallejo primer through it, and it was only spitting, rather than spraying smoothly.

I decided to break it down and clean it to see if that solved the problem.

Soaked the smaller parts in some brush cleaner for a bit, before scrubbing them and putting everything back together.

I now am unable to spray even water out of the brush! All the air is bubbling back up through the cup when I press the lever, and nothing out of the end when a pull it back.

This is the exact brush I am using,

This is the parts diagram so the airbrush veterans can see how it all fits together (spoilers for ginormousness)

Spoiler:

Any suggestions? The paint and air pathways all seem to be completely clear with no sign of paint residue.

**davethepak**

Does the needle stick out of the end?

Something is blocking the front.

**Azreal13**

Yep, as my thumb and finger can attest to while I've been trying to fix it!

I've been playing further and it seems the nozzle, which I recently replaced, is damaged or faulty, as I discovered that it is compatible with my tatty, old brush and the problem followed it when transferred it into that.

Oh well, they're not expensive, but I've got a deadline to complete this piece, could do without the delay.

**Desubot**

That would be a sign of clogging IIRC. where the air rushes back from the tip back into the cup. try cleaning it again. (personally i clean all my parts in purple power (Striping agents) and it takes most of everything out on my badger krome. dunno if your chines knock off will melt in that kinda stuff

**Ouze**

Try running a little bee's wax on the problematic part of the nozzle?

**Azreal13**

Desubot wrote:
That would be a sign of clogging IIRC. where the air rushes back from the tip back into the cup. try cleaning it again. (personally i clean all my parts in purple power (Striping agents) and it takes most of everything out on my badger krome. dunno if your chines knock off will melt in that kinda stuff

No, it is still made of metal, that doesn't get chemically altered on cheap brushes!

Have ordered a replacement nozzle, I've cleaned, visually checked and physically blown through, all aspects of the head of the brush. When the problem moves to another brush with the exchange of one part, that's a clear indicator of the problem in my book.

**Desubot**

Damn Ouze nice resources.

**Azreal13**

If your airbrush has a screw-in nozzle like the one on the right, you may have a gasket, possibly made of Teflon, to seal off the nozzle to body joint. You didn’t lose the gasket did you? Over time, these gaskets can be compressed enough that they leak. This is an easy fix. Just replace the gasket. I've also found that a little lip balm, like Chapstick, on the threads can solve the problem.

If you have a tiny screw-in nozzle like the Iwata HP-CR on the right, you may need some sealant like bees wax or lip balm on the threads. Be extremely careful not to over tighten it.

The only other place that air can get into the paint path is at the tip of the nozzle, like when you back flush by holding your finger or a paper towel against it. A tiny crack in the end of the tip can cause bubbles. Check it closely with a magnifying glass. I’ve read that paint build-up can occur here and also cause bubbles. I’ve never seen this, but it's worth checking for.

In order to create a vacuum to pull paint out of the brush, the nozzle has to protrude just a tiny bit past the front of the spray regulator. If it doesn't, you can get pressure instead of a vacuum here and air will blow back into the cup or bottle. This can be a problem in airbrushes with rubber O-rings in the head assembly.

This could be the issue too I suspect?

Hmm, off to see I guess!

Automatically Appended Next Post:
Applied some Vaseline to the nozzle thread.

Noticeable improvement, but still poor spray pattern and some air making it back up into the cup.

Suspect I had simply needed to do this in the first place, but constant fiddling has resulted in further damage to a small and delicate piece.

Will have to wait for replacement to arrive and then use some sealant when I install.