Painting along. Using Tamiya paints thinned with MLT. I put down one color of paint on a bunch of parts for my Huey. Blew out the remainder of the paint, ran a couple of rinses of lacquer through it. Put in another color thinned with MLT and … nothing. Swabbed the tip. Nothing. Turned up pressure to max, nothing. So emptied the paint out and gave the whole airbrush a good cleaning. Reassembled it and tried to run a little lacquer through it, and … nothing. Air comes out. Paint does not.
I’m baffled…
FWIW, it’s an HP-CR that is about a year old I think. It replaced my previous HP-CR, and I never had the problem with that.
If you are getting air but no paint, take the whole brush apart. Then see if you can run a pipe cleaner or soft wire through from the color cup out the front of the airbrush. You should be able to. That should clear the blockage.
Thanks. I have discovered the problem, but it still leaves me scratching my head…
The nozzle, where the needle comes out is clogged. I figured this out by looking at my old brush and my new. So I took the nozzle from my old brush and put it on the new and it works fine. I guess I don’t understand how these work actually. I figured if that nozzle is clogged, neither air nor paint nor water nor anything would escape, but that doesn’t seem to be the case. I need to find something small enough to run through the nozzle I guess…
And maybe it’s time to learn about ultrasonic cleaners for airbrushes.
On my AB he paint flows through the hole in the nozzle when I pull the needle back. The air passes around the outside of the nozzle to create the vacuum that pulls the paint out of the nozzle. So, I can get air to flow with the nozzle closed, by simply pushing down on the trigger without pulling back to open the needle. That means the nozzle can be clogged while the air can flow.
If you have gunk in the nozzle, take it off the AB and soak it in a solvent - I spray some Badger Airbrush Cleaner through mine as it is Xylene-based. That stuff strips all the paint out! (But wear protective gloves and do it outdoors - you don’t want it on your skin or in your lungs!)
To clean the inside of a nozzle, I soak it in lacquer thinner, then with a reasonably fresh blade, cut thin slithers to a fine point from a wooden toothpick which I soak in thinner too. I then use these to clear out the nozzle, gently. The wood is soft enough to not damage the nozzle. It is really surprising the gunk you can get out from what you thought was a spotless nozzle.
Did you add Tamiya Flat Base or Vallejo Flow Improver? I think the reason for the clogging is that the paint is drying too soon and the Flat Base and Flow Improver should prevent this.
Interesting. I’ve never added flat base to anything. I add Mr Leveling Thinner to think things down. Can one add Vallejo Flow Improver to that? Does one need to?
Vallejo Flow Improver is not hype. I’ve had issues with Vallejo AIR blobbing up inside my airbrush because it doesn’t thin down well…it clumps up with water and thinner. Adding Vallejo Flow Improver prevented this, and I add Flow Improver to everything now, no matter what brand of paint. Vallejo Flow Improver is sold on Amazon.
As for Tamiya Flat Base, it is necessary to prevent the “pebble grain” finish when airbrushing on models. Flat Base is like a gel, similar to toothpaste. An expert Gundam modeler told me this…Tamiya won’t tell you that their paint dries so fast in mid-air right out of the airbrush that it splatters onto the plastic or there is no paint getting onto the model kit. With Tamiya Flat Base added, Tamiya paint has a retarder that makes the paint more wet and dries longer and thus won’t clog. I use 1/3 Tamiya Flat Base, 1/3 Tamiya paint, and 1/3 thinner or water and it sprays on smoothly. That is why Gundam models’ armor look so smoothly painted with Tamiya Flat Base mixed with Tamiya paint and airbrushed on.
If you want to airbrush straight from the paint bottle, the least you can do is add Vallejo Flow Improver. It took me years to learn this…I learned it from YouTube when I searched for an answer to the problem that you’re encountering. Remember, Tamiya Flat Base is not Tamiya Flat Clear. Both are sold on Amazon.
Using Mr Leveling Thinner does the same as Flat Base. Not sure you can add Vallejo Flow Improver with Tamiya paint because it’s a different type of acrylic. I would use a few drops of Tamiya Retarder with MLT.
$6 for 200. These are dental items but are perfect for cleaning the inside of nozzles. Soak your nozzle in lacquer thinner for a few minutes. Then take your wet nozzle and insert a paper point with a pair of tweezers. Twist the nozzle against the paper point. You will be amazed at the amount of gunk you get out of a “clean” nozzle. You’ll see colors you used 3 sessions ago. Repeat until the point comes out clean.
I do this at the end of every session and my airbrushes never clog.
Paper tips ordered. Thanks for that, um, tip… Seems like they might have other uses? (I mean hobby uses, I’m not going to start doing root canals on friends and family…)
Thanks @barkingdigger for the physics of the airbrush explanation. That makes sense.
I only use Tamiya, AK, MRP, and Mr Color, and am hesitant to try the vallejo flow improver with those. I thought MLT worked as both a flow improver and a retarder, but I may be mistaken?
No Phil you’re correct. MCLT is both a flow improver and retarder, that’s why it gives such excellent results. Vallejo flow improver will not work with your paints, all lacquers.
Oh, go on - you know you want to do some root canals!
I mainly spray Tamiya acrylics, mixed about 60:40 with their thinner X-20A, and have no issues other than the limits of my own competence. I haven’t needed any flow improvers so far - the paint goes on wet as long as the distance isn’t too big.
And don’t blow all the excess paint out to empty the cup - that’s just asking for it to dry in the nozzle! Pour out the excess as soon as you’re done, then blow thinners through to clear out the paint from in the nozzle, even if you’re only pausing to reload with a new colour.
First, got the paper tips. Great tip, ahem. These things are tiny.
After a few attempts at soaking and picking at it with a dental pick I got a lot of gunk out but it was still blocked. I think there was something solid in the opening. I ended up using a tiny piece of wire and pushing it in from the outside of the tip. I didn’t see what came out but that cleared it and it’s back in action again.
The paper tips are going to be useful nonetheless.
