Does 0.5mm need more air pressure than 0.3mm setup?

M

Melbee

Guest
Hi Folks,
Sorry if this is a dumb question but I just swapped out my 0.3mm needle and nozzle on my Chinese airbrush for their 0.5mm needle and nozzle but it didn't work! I was using 40 psi and I noticed the air pressure felt a lot weaker with the 0.5mm setup. Is it normal to have to up the air pressure if you up the needle size? I would have thought 40 psi was enough.

I had been spraying a background with my Eclipse 0.3mm and wanted to get wider coverage which is why I tried the 0.5mm for the first time. I had to give up and go back to using my Iwata HP-SBS 0.3mm which I love by the way :)

If my 0.5mm airbrush should spray at 40psi I'll go back and give it a strip down. If I was just being dumb and needed to up the air pressure, I'll know what to do next time.

Advice please
cheers Mel
 
.5 is the main nozzle set up that most airbrush artist use , They usually run straight Createx through them at about 60 PSI.
But If you are reducing your paint you can use the .5 like you would a .35 or even smaller.
Mainly comes down to what you are trying to do and what paint you are using.
 
.5 is the main nozzle set up that most airbrush artist use , They usually run straight Createx through them at about 60 PSI.
But If you are reducing your paint you can use the .5 like you would a .35 or even smaller.
Mainly comes down to what you are trying to do and what paint you are using.

Thanks Herb,

I was painting an even colour background on a T shirt using Golden Fluid paint with Airbrush Medium 1:1 ratio. I had been spraying this mix with my Eclipse HP-SBS 0.3mm at 40 psi with no trouble but the coverage was taking a long time. I then remembered I had bought a 0.5mm needle and nozzle for my Chinese knockoff (you can put 0.2, 0.3 and 0.5mm set ups in them), so I thought I'd give it a try. I expected to get better coverage from a 0.5mm but noticed straight away that the 40 psi air pressure felt weaker when I tested it on my hand so I upped the psi and it still didn't spray well.

I think I need to strip them down, give them a clean and try again with a higher pressure. The airbrushes have been sat unused for many months and I noticed the superlube had gone thick on the needle so maybe there was superlube blocking the nozzle.

I just wondered if it was common practise to up the psi if you up the needle/nozzle size like a gravity feed airbrush needs less psi than a siphon feed.
Cheers Mel
 
I just shot some airbrush cleaner through both my Veda's and let them sit for a while. I've tested both with the same paint mix as yesterday and they are working now. I think the Superlube had thickened up and clogged the nozzle. They will work at 40 psi but 50 seems a bit better but I don't like using either. The atomisation is not good and I've been spoiled by my Eclipse which I've been using on this T shirt. If I continue to paint T shirts I'll think about getting a 0.5mm make airbrush but for now I'm just learning and my Aircom 20A compressor is a bit small for T shirts painting. It's already getting hot at 40 psi and it's oil filled. In future I will make designs that don't need block colour backgrounds :) But this time I am covering up a mistake so I had to do it or I wouldn't wear it.
 
OK I take it back about the Veda's. I decided to try actually spraying my T shirt background with the Veda WD134 with 0.5mm setup and it sprayed quite well at 50 psi. It would be rubbish for detail and it did spit a bit but the coverage was ok.
 
Not sure if this helps but I have an eclipse cs and a bcs. I took all the parts out of the bcs. Ie nozzle, needle and air cap and put them on the cs. I now have a .5 cs. I prefer the gravity feed cup to the bottle. Bcs parts are pretty cheap so you could have two setup just be sure to keep it all separate. The air cap is hard to identify.
 
It is not the size of the needle that makes that happen it how much CFM the brush uses. A syphon feed will demand more CFMs to pull the paint then a gravity feed. A good example is an air gun draws a whole lot more CFMs at 10 psi. than an Iwata Eclipse BCS at 40 psi.

Fred
 
I'm not a textile painter, but I've known plenty, and many of them say they'll run up to 60 psi. The idea being that the higher pressure will force the pigment deeper into the fabric, I guess.
But, pretty much any airbrush should work at least as low as 35psi, even a siphon-fed airbrush. Every different model and brand seem to have their own "sweet spot" for air pressure, though. My HP-CS doesn't like anything below 30psi or so, while my HP100-C (original, Olympos version of the HP-C) works best around 25psi. Both gravity fed, tip sized are with in 0.05 of each other (.35 and .3, respectively). Yet they each have their own little "happy places".


I have a PEAK X-5, which is the only siphon-fed airbrush I own, that has a .5 tip on it. When I do occasionally use it, 35psi feels like too much, and 30psi feels a bit low, so I keep it somewhere in between. The only way to figure these things out is to spend time expirimenting.
 
Thanks a lot guys. Looks like I've got more experimenting to do.

Tigertron, I'll look into the bcs 0.5 set up but I really like my Eclipse 0.3 and don't think I want to mess with it.
Cheers everyone
Mel
 
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