Nozzle blocking

[muppetmic]

Hello

 

I am using  harder and steenback infinity CR with humbrol 90 acrylic paint.

I am using a mix of aclcohol and water with a retarder and flow improver.

Everytime  I start to spray it works for about 10 seconds then the paint flow stops.

When i investigate the paint in the nozzle  is really thick.

I have repeatably cleaned everything, i can see no damage to the needle.

It doesnt matter how thin i make the paint it keeps happening.

I would be grateful if someone can help.

 

Mic

 

[Stephen]

I think it might be the alcohol causing the paint to thicken as water based acrylics don't respond well to alcohol, are you using the older Humbrol Acrylics or the newer range in the dropper bottle? I haven't sprayed Humbrol Acrylics for several years and it was the older one that came in the plastic pot. At the time I thinned that with Xtracrylix thinner and it worked OK. 

 

If you're using the newer acrylics (dropper bottle) then I would suggest just thin with water and add some retarder and see how that sprays. You could also try deionised water which you can buy or (much easier and cheaper) boil the kettle then let it cool down and use that to thin.

 

HTH

[Tijuana Taxi]

If you are using the 0.15 needle perhaps for this paint try the 0.4 that you can get for your airbrush.

Also try upping the psi although I don't know what you are using already so just a thought

 

You could perhaps try thinning just with flow retarder, I have used that method successfully with other non airbrush specific acryllic.

Edited January 2, 2022 by Tijuana Taxi

[muppetmic]

4 hours ago, Stephen said:

I think it might be the alcohol causing the paint to thicken as water based acrylics don't respond well to alcohol, are you using the older Humbrol Acrylics or the newer range in the dropper bottle? I haven't sprayed Humbrol Acrylics for several years and it was the older one that came in the plastic pot. At the time I thinned that with Xtracrylix thinner and it worked OK. 

 

If you're using the newer acrylics (dropper bottle) then I would suggest just thin with water and add some retarder and see how that sprays. You could also try deionised water which you can buy or (much easier and cheaper) boil the kettle then let it cool down and use that to thin.

 

HTH

Thanks I will try leave the alchoohol out and just add demineralised water

[Mike]

Just a quick extra to what's already been said.  Humbrol DEFINTELY doesn't like neat alcohol.  I've also had issues with H&S airbrushes and Humbrol, as at the time their pigment grind was something akin to moon rocks I couldn't even get it to spray reliably through a 0.35mm nozzle, nevermind my usual 0.2mm.  As another poster has suggested, try 0.4mm if you have it, and work your way down.

 

You may also get some positive feedback from adding some flow improver to your paint.  Just a drop in the cup, mixed in, and it will help reduce drying on the tip of the needle.  Also, try to blow just air as little as possible while you're spraying, as it will encourage any paint on the needle to dry, leading to the obvious issue

[muppetmic]

2 hours ago, Mike said:

Just a quick extra to what's already been said.  Humbrol DEFINTELY doesn't like neat alcohol.  I've also had issues with H&S airbrushes and Humbrol, as at the time their pigment grind was something akin to moon rocks I couldn't even get it to spray reliably through a 0.35mm nozzle, nevermind my usual 0.2mm.  As another poster has suggested, try 0.4mm if you have it, and work your way down.

 

You may also get some positive feedback from adding some flow improver to your paint.  Just a drop in the cup, mixed in, and it will help reduce drying on the tip of the needle.  Also, try to blow just air as little as possible while you're spraying, as it will encourage any paint on the needle to dry, leading to the obvious issue

 

thanks mike, so just plain water and retardent

[Mike]

20 hours ago, muppetmic said:

 

thanks mike, so just plain water and retardent

You could try it with just water (deionised as someone else suggested), then add retardant if you're still getting drying on the tip