H&S Sputtering

[Grasdarost]

Hi,

I've recently purchased a Harder&Steenbeck Ultra 2 in 1, to replace a cheap chinese airbrush that I've been using for the last six months.

Since the first test with the new airbrush, I've had the same problem: it sputters badly as soon as I press the trigger for air. It starts sputtering few seconds after loading the paint, projecting a small cloud of darker dots or a larger, single drop farther away. I've thought that the issue may be the thinner ratio, so I've tried thinning the paint I'm using (Vallejo Model Air) much more than usual, adding flow improver, changing the pressure. Always the same results. And the sputter presented also with Tamiya paints (diluted 1:1) and with the 0.4 needle included in the box.

I've spent a lot of time cleaning thoroughly every part (I've noticed that there seems to be a lot of paint accumulating in the needle and and the nozzle), checking for cracks or bent needle, but nothing seems to be out of place.

I am a bit disappointed because I've never had this kind of issues with the chinese airbrush...

 

Am I doing something wrong or there's some problem in the airbrush?

 

Thank you

Bye

[little-cars]

Hi,  

Have you checked that you have the right needle, nozzle, aircap in each of the nozzle  of the two sets?

Is the problem still there if you put water through the brush?   Do you flush the brush through with water when changing paint types ?

 

One thing to try is to stay with one range of paints.  Vallejo doesn't like  Tamiya thinners.

 

Paul

 

 

 

 

[bmwh548]

Make sure you have to correct needle-nozzle-cap combination. If that's not the case you might want to check if the needle goes in all the way. To me it kinda sounds like the needle is ever so slightly retracted causing small amounts of paint/thinner to seep through and build up on the tip/in the cap. When you press the trigger that will push the tiny droplets away. Unscrew the needle chuck at the back, pull the needle out, give it a good wipe, make sure it slides fairly easy through it's PTFE seal (which is right behind the paint cup), make sure it's pushed all the way forward (but don't force it so you don't crack the nozzle) and screw the chuck back up. See if that fixes it.

[jenko]

I know this sounds daft but have you got the needle clutch tightened up? Also a little lubrication on the  air valve  might help.

 

Dick

[Grasdarost]

Thank you for your help.

 

I've checked the nozzle-needle coupling and they match according to this image (the official Harder&Steenbeck site is a bit confusing):

I've then checked the needle position and the tightening, trying to tighten a little bit more than before. I've noticed a small improvement so probably something was a bit loose and I've tried to spray paying attention to not releasing the trigger before having pulled it forward. That seemed to remove most of the sputtering, with Vallejo Model Air slightly thinned.

 

I then tried to spray some black primer (Vallejo): probably not the smartest thing to do with a .2 nozzle, but the results was a disaster. I wasn't even able to spray once. The airbrush clogged instantly and then released a giant splotch. Paint went literally everywhere, inside and outside of the airbrush. I found lot of paint on the needle, the needle cap, in the air cap, on the treads of the air cap and some traces even on the trigger and on the back of the needle seal... It took me a long time to clean everything (at this point, I've spent far more time cleaning than painting). Is this a sign of something wrong or was I just dumb in trying to spray primer?

 

Thank you again

Michele

[malpaso]

That Valljo black primer is horrible.  It gums up my Ultra or my Evolution in .4 and also finds its way into all sorts of tiny nooks and crannies inside the airbrush, despite being too thick to come out of the noxzle where its supposed to !

[Sharknose]

I have the same airbrush and no matter how careful I am with everything these small splatters of paints happen. I generally use Tamiya acrylics thinned with Tamiya thinners or IPA (until Covid made it more expensive than saffron).

 

I have found it best as I start to spray, to spray paint just to the side onto some paper towel, ease the trigger forward until just air, back over the target and paint. 

 

To clean my needle I was dropping it into a small bottle of cellulose thinners and I think I slightly damaged the tip of the 0.2mm needle, as I could feel it drag on a cotton bud when cleaning, so gently sanded it smooth.

Edited June 2, 2020 by Sharknose

[bmwh548]

I polish the tip fairly whenever I start to see wear marks on it. Works fine. I'm sure I've changed the geometry of the tip , but it still gets the job done.

[SodaCitron]

Don't use anything alcohol based with Vallejo paints, otherwise they will turn into a kind of goo. Use the brand thinner AND a couple of drop of flow improver. The flow improver is really a game changer as it delays the drying time and therefore the dry tip.

[uncletommy]

Has it been rather humid where you are?  Does your compressor have a water trap on it?    

If you get moisture in the line, it can spatter and generally ruin your day.  

 

Also, a 0.2mm tip is pretty small unless you've thinned the primer quite a bit.  While I use Mission Models paints and primers, I find I have to thin the Mission Models primer about 50:50 to get it through my H&S Evolution with the 0.2mm tip.  The only primer I've been able use without any thinning is Badger Stynylrez with a 0.4mm needle set.