airbrush problem
Discussion
I've had a really cheap single action airbrush for a while (a Spirit Air one with a tiny compressor) but the entire nozzle broke off recently so I bought one of these:
https://www.amazon.co.uk/Mini-Airbrush-Compressor-...
The problem is that no matter what pressure I set it to and on both light and heavy trigger pressing the paint seems to spray fine for anything from 2 seconds to 20 seconds, then paint flow stops. Air is still flowing but just no paint. A tiny further depression of the trigger gets it going again but often results in a brief large splod of paint.
I epoxied the nozzle back onto the old airbrush as a test, trying both airbrushes on both compressors and the newer dual-action airbrush showed the same behavior issue on both compressors, whereas the cheapo glued airbrush was fine on both.
I'm using Tamiya acrylic paint thinned with 50% Tamiya acrylic thinners.
Anyone have any idea what I am doing wrong or what could be up with the new airbrush? I've stripped it apart, cleaned it with airbrush cleaner and water etc.. tried different air pressure settings on the compressor (from about 5 up to 40) , set the needle adjustment loose and tight but no change to this issue so far.
https://www.amazon.co.uk/Mini-Airbrush-Compressor-...
The problem is that no matter what pressure I set it to and on both light and heavy trigger pressing the paint seems to spray fine for anything from 2 seconds to 20 seconds, then paint flow stops. Air is still flowing but just no paint. A tiny further depression of the trigger gets it going again but often results in a brief large splod of paint.
I epoxied the nozzle back onto the old airbrush as a test, trying both airbrushes on both compressors and the newer dual-action airbrush showed the same behavior issue on both compressors, whereas the cheapo glued airbrush was fine on both.
I'm using Tamiya acrylic paint thinned with 50% Tamiya acrylic thinners.
Anyone have any idea what I am doing wrong or what could be up with the new airbrush? I've stripped it apart, cleaned it with airbrush cleaner and water etc.. tried different air pressure settings on the compressor (from about 5 up to 40) , set the needle adjustment loose and tight but no change to this issue so far.
Airbrush cleaner may not be strong enough for whatever may be blocking the fine pathways (definitely dont waste your time with water).
Try IPA or enamel thinners.
Also, sorry if I am stating what you already know, but in your post, you only talk of depressing the trigger. You may need to pull back the trigger more to get the paint flowing. Down for air, back for paint.
Also check when you tighten up the needle screw at the back that it is actually clamping on the needle and not slipping.
lol Also finally check the tip of your needle isn't bent
Try IPA or enamel thinners.
Also, sorry if I am stating what you already know, but in your post, you only talk of depressing the trigger. You may need to pull back the trigger more to get the paint flowing. Down for air, back for paint.
Also check when you tighten up the needle screw at the back that it is actually clamping on the needle and not slipping.
lol Also finally check the tip of your needle isn't bent
The_Jackal said:
Airbrush cleaner may not be strong enough for whatever may be blocking the fine pathways (definitely dont waste your time with water).
Try IPA or enamel thinners.
Also, sorry if I am stating what you already know, but in your post, you only talk of depressing the trigger. You may need to pull back the trigger more to get the paint flowing. Down for air, back for paint.
Also check when you tighten up the needle screw at the back that it is actually clamping on the needle and not slipping.
lol Also finally check the tip of your needle isn't bent
Yeah sorry, when I said depressing the trigger I meant moving it backwards for more paint flow. The needle is straight (the entire thing is only 10 days old) and is clamping tight at the back.Try IPA or enamel thinners.
Also, sorry if I am stating what you already know, but in your post, you only talk of depressing the trigger. You may need to pull back the trigger more to get the paint flowing. Down for air, back for paint.
Also check when you tighten up the needle screw at the back that it is actually clamping on the needle and not slipping.
lol Also finally check the tip of your needle isn't bent
dr_gn said:
Sounds to me like either you’ve got lumpy paint and/or too thick paint and/or paint is drying on the needle.
Try filtering your paint through a tea strainer (or similar), make sure your paint is thin enough (milky consistency), and use a retarder to prevent drying.
Thanks for the info.Try filtering your paint through a tea strainer (or similar), make sure your paint is thin enough (milky consistency), and use a retarder to prevent drying.
The paint is new Tamiya acrylic straight from the pot into a new plastic bottle then mixed with 50% acrylic thinners, and I don't see the same issue on the other airbrush. I'll try it thinner and see what happens.
I'll also try a retarder / flow improver or similar to see if that helps, but it's odd it happens with one airbrush and not the other.
Edited by anonymous-user on Thursday 26th July 09:16
The Dangerous Elk said:
Thanks, lots of info on there, I will have a read.The new one is listed as 0.2 - 0.3, whatever that means, but the old one was the cheapest one from AliExpress and I've no idea what needle it uses.
I don't see any movement in the needle when the paint stops, I am holding my finger very still but it still happens. The new airbrush has a needle stop so I've set that to multiple positions so the needle can be pulled back against the stop to remove any "finger wobble" but the paint flow still stops just the same. It seems however to only take a little bit of extra pressure to make the paint flow again, but typically in a big splatter, so it's as if the needle *is* moving back a bit but independently of the trigger, if that's possible?
I've tried swapping needles , swapping the rear casing, swapping the air inlet nozzles, the frontmost nozzle etc..., every part than can be moved from one brush to the other, but the new airbrush just still won't give a constant paint flow. I've also had it in pieces, down to the nylon needle bush in the middle, and it was clean, soaked it in soapy water for a few hours, left it full of airbrush cleaner , I've even filed the hole at the bottom of the paint reservoir a bit to smooth the edge.
I've also tried various brands of acrylic paint , using more thinners , using flow improver and retarder
None of these things have altered the behavior, so I am stumped
I don't see any movement in the needle when the paint stops, I am holding my finger very still but it still happens. The new airbrush has a needle stop so I've set that to multiple positions so the needle can be pulled back against the stop to remove any "finger wobble" but the paint flow still stops just the same. It seems however to only take a little bit of extra pressure to make the paint flow again, but typically in a big splatter, so it's as if the needle *is* moving back a bit but independently of the trigger, if that's possible?
I've tried swapping needles , swapping the rear casing, swapping the air inlet nozzles, the frontmost nozzle etc..., every part than can be moved from one brush to the other, but the new airbrush just still won't give a constant paint flow. I've also had it in pieces, down to the nylon needle bush in the middle, and it was clean, soaked it in soapy water for a few hours, left it full of airbrush cleaner , I've even filed the hole at the bottom of the paint reservoir a bit to smooth the edge.
I've also tried various brands of acrylic paint , using more thinners , using flow improver and retarder
None of these things have altered the behavior, so I am stumped
JimSuperSix said:
The new one is listed as 0.2 - 0.3, whatever that means, but the old one was the cheapest one from AliExpress and I've no idea what needle it uses.
I don't see any movement in the needle when the paint stops, I am holding my finger very still but it still happens. The new airbrush has a needle stop so I've set that to multiple positions so the needle can be pulled back against the stop to remove any "finger wobble" but the paint flow still stops just the same. It seems however to only take a little bit of extra pressure to make the paint flow again, but typically in a big splatter, so it's as if the needle *is* moving back a bit but independently of the trigger, if that's possible?
I've tried swapping needles , swapping the rear casing, swapping the air inlet nozzles, the frontmost nozzle etc..., every part than can be moved from one brush to the other, but the new airbrush just still won't give a constant paint flow. I've also had it in pieces, down to the nylon needle bush in the middle, and it was clean, soaked it in soapy water for a few hours, left it full of airbrush cleaner , I've even filed the hole at the bottom of the paint reservoir a bit to smooth the edge.
I've also tried various brands of acrylic paint , using more thinners , using flow improver and retarder
None of these things have altered the behavior, so I am stumped
The 0.2mm is the diameter of the opening in the nozzle; 0.2 is considered a 'standard' nozzle.I don't see any movement in the needle when the paint stops, I am holding my finger very still but it still happens. The new airbrush has a needle stop so I've set that to multiple positions so the needle can be pulled back against the stop to remove any "finger wobble" but the paint flow still stops just the same. It seems however to only take a little bit of extra pressure to make the paint flow again, but typically in a big splatter, so it's as if the needle *is* moving back a bit but independently of the trigger, if that's possible?
I've tried swapping needles , swapping the rear casing, swapping the air inlet nozzles, the frontmost nozzle etc..., every part than can be moved from one brush to the other, but the new airbrush just still won't give a constant paint flow. I've also had it in pieces, down to the nylon needle bush in the middle, and it was clean, soaked it in soapy water for a few hours, left it full of airbrush cleaner , I've even filed the hole at the bottom of the paint reservoir a bit to smooth the edge.
I've also tried various brands of acrylic paint , using more thinners , using flow improver and retarder
None of these things have altered the behavior, so I am stumped
Assuming the needle isn't bent, and is pulling back consistently and not snapping forward, that means there's an 'O' shaped opening at the nozzle. The 'O' gets thicker or thinner as you move the needle back and forth, letting more or less paint through.
Assuming your air supply is constant, and the opening is there, and paint flows initially, it can only mean that the 'O' is getting blocked, or the paint is becoming too thick to flow through it. When you let the trigger go, the needle goes forward and pushes the blockage to the needle tip. When you try again, the blockage debris gets blown off the needle in a splatter (even if you don't pull it back - the air blows around the nozzle when the trigger is depressed, and will blow any debris off the needle tip, which protrudes beyond it).
It sounds like your paint is lumpy, or it's drying on the needle as you're spraying. The other thing is debris in the paint - even fibres from a tissue used for cleaning the cup out can easily casue a blockage. You have to be scrupulously clean when preparing an airbrush.
Try spraying water onto some dark card and see what happens. I know a few people with cheap airbrushes who never got them working properly. Spend £60 and avoid the hassle:
https://www.modellingtools.co.uk/harder--steenbeck...
Edited by dr_gn on Wednesday 1st August 16:10
I don't think the paint is lumpy - it's brand new Tamiya acrylics right out of the glass jar and into a brand new small plastic bottle, then mixed with new Tamiya thinners to 50%. I've also tried about 90% thinners and it still does the same thing, so i can't really go any thinner as it would take months so actually paint anything.
Also swapped needles between the 2 airbrushes and got the same results.
I've bought a new one now with 0.2 , 0.3 and 0.5 tips so hopefully I'll have more success with that.
Also swapped needles between the 2 airbrushes and got the same results.
I've bought a new one now with 0.2 , 0.3 and 0.5 tips so hopefully I'll have more success with that.
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