Atomization - True or false?

I have both an HP-TH and an Eclipse with both a .5 and a .35 setup, so I can answer that.

The HP-TH has better atomization. The Eclipse in both .5 and .35 configurations does finer lines.

The HP-TH cannot do fine lines because the needle/nozzle taper is too blunt, so the distance required to do fine lines is shorter than the height of the nozzle cap. It's a brush designed to spray a wide cone at high volume for large scale coverage. It has better atomization than the Eclipse because the airflow in the head is better/more precisely engineered.

The difference between the .5 and .35 setups in the Eclipse is mostly in how they handle. There is no difference that I can detect in atomization or max paint volume. The .5 lets you spray paints with larger or more irrgular pigment particles, at the cost of the trigger travel between "fine line" and "full blast" being dramatically shorter. Both can do equally fine lines, but the .5 requires finer finger control to find and maintain the trigger sweet spot for a given line.

I have 2 Badger SOTARs which have smaller needle/nozzles with a steeper taper than the Eclipse. They have finer atomization the the Eclipse, but not as fine as the HP-TH. They do not do finer lines than the Eclipse, but the lines are crisper, and the trigger travel needed to find and hold the sweet spot for a given line is more forgiving.

I have 2 Paasches, a VL and an H, niether of which can do fine lines because the airflow cone is very "soft" regardless of pressure, resulting in spray patterns with shallow, fuzzy gradients. If I try to do fine lines, I get thick fuzzy lines that are basically all overspray and no core.

In my experience, anything with a needle taper which puts the apex of the paint spray far enough out to be acessable can do fine lines, as long as atomization and airflow cone is "good enough", and your hand/finger control is good enough to hold things in the right position. If atomization is really bad, the lines will have a granular look instead of smooth. How crisp the line edges are has to do with the airflow pattern: anything with passable atomization can do crisp lines as long as the airflow cone has a crisp boundary. This requires careful design and precise machining, I should think, and so would be likely to coincide with finer atomization as brushes go up in quality, even if the two are not necissarily directly linked.

Conversely, it is entirely possible to have a brush which produces very fine atomization, but does not produce crisp lines because the airflow cone has too "soft" a boundary. Such brushes would be able to do fine lines, but the lines would always have "fuzzy" gradient edges instead of being crisp.

Steeper/longer needle tapers result in a longer, narrower airflow cone, making trigger travel and tip distancing more forgiving. This makes it easier to control fine lines, but does not necissarily mean finER lines.

So brush X being objectively able to do finer lines than Brush Y would mean a combo of:
1: A "good enough" minimum of atomization fineness/quality, in which droplet size and spacing is no greater than X% of the target line width, and
2: An airflow cone which is crisp enough to keep paint spray confined more tightly, resulting in a spray pattern with a steeper gradient at its edges.

Other elements like needle taper and minimum air pressure make fine lines easier, but not more or less possible in a binary sense.

Provided those two elements are in place, the brush can do equally fine lines... for a given value of "fine", naturally. The tinier the line, the more restrictive those variables have to be. However, my Eclipse can go hair thin with either setup, so IMO a "better" brush is one which makes it ergonomically easier (a steeper needle/nozzle taper), or which produces better gradients ( tighter air cone boundaries for crisp lines, finer atomization for blended edges).
 
Now I will understand what you guys are talking about :D
Think of the needle size as how much space is around the needle to let paint thru when at it's max opening It also has something to do with how fine the paint pigment is ground in the paint you use,Because the finer the pigment the better it will Atomize because it can move freely thru the smaller opening, Bigger size pigments clog the airbrush unless its forced thru at higher pressures
 
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I have both an HP-TH and an Eclipse with both a .5 and a .35 setup, so I can answer that.

The HP-TH has better atomization. The Eclipse in both .5 and .35 configurations does finer lines.

The HP-TH cannot do fine lines because the needle/nozzle taper is too blunt, so the distance required to do fine lines is shorter than the height of the nozzle cap. It's a brush designed to spray a wide cone at high volume for large scale coverage. It has better atomization than the Eclipse because the airflow in the head is better/more precisely engineered.

The difference between the .5 and .35 setups in the Eclipse is mostly in how they handle. There is no difference that I can detect in atomization or max paint volume. The .5 lets you spray paints with larger or more irrgular pigment particles, at the cost of the trigger travel between "fine line" and "full blast" being dramatically shorter. Both can do equally fine lines, but the .5 requires finer finger control to find and maintain the trigger sweet spot for a given line.

I have 2 Badger SOTARs which have smaller needle/nozzles with a steeper taper than the Eclipse. They have finer atomization the the Eclipse, but not as fine as the HP-TH. They do not do finer lines than the Eclipse, but the lines are crisper, and the trigger travel needed to find and hold the sweet spot for a given line is more forgiving.

I have 2 Paasches, a VL and an H, niether of which can do fine lines because the airflow cone is very "soft" regardless of pressure, resulting in spray patterns with shallow, fuzzy gradients. If I try to do fine lines, I get thick fuzzy lines that are basically all overspray and no core.

In my experience, anything with a needle taper which puts the apex of the paint spray far enough out to be acessable can do fine lines, as long as atomization and airflow cone is "good enough", and your hand/finger control is good enough to hold things in the right position. If atomization is really bad, the lines will have a granular look instead of smooth. How crisp the line edges are has to do with the airflow pattern: anything with passable atomization can do crisp lines as long as the airflow cone has a crisp boundary. This requires careful design and precise machining, I should think, and so would be likely to coincide with finer atomization as brushes go up in quality, even if the two are not necissarily directly linked.

Conversely, it is entirely possible to have a brush which produces very fine atomization, but does not produce crisp lines because the airflow cone has too "soft" a boundary. Such brushes would be able to do fine lines, but the lines would always have "fuzzy" gradient edges instead of being crisp.

Steeper/longer needle tapers result in a longer, narrower airflow cone, making trigger travel and tip distancing more forgiving. This makes it easier to control fine lines, but does not necissarily mean finER lines.

So brush X being objectively able to do finer lines than Brush Y would mean a combo of:
1: A "good enough" minimum of atomization fineness/quality, in which droplet size and spacing is no greater than X% of the target line width, and
2: An airflow cone which is crisp enough to keep paint spray confined more tightly, resulting in a spray pattern with a steeper gradient at its edges.

Other elements like needle taper and minimum air pressure make fine lines easier, but not more or less possible in a binary sense.

Provided those two elements are in place, the brush can do equally fine lines... for a given value of "fine", naturally. The tinier the line, the more restrictive those variables have to be. However, my Eclipse can go hair thin with either setup, so IMO a "better" brush is one which makes it ergonomically easier (a steeper needle/nozzle taper), or which produces better gradients ( tighter air cone boundaries for crisp lines, finer atomization for blended edges).
Thats what I was trying to get at.
Though I could never have explained that all so clearly.
 
Great thread, very good info, clearly stated. I'm sure this will cure a lot of beginner (and old dog) curiosity...
 
Been hiding in my hole m8 :) You know me love the science of the airbrush m8 more than the airbrush atm it seems LOL but need to pull it out again for a few jobs so pop back in here to find inspiration again, have been lurking through seeing some awesome works going on. but have found a quieter me :)
 
Been hiding in my hole m8 :) You know me love the science of the airbrush m8 more than the airbrush atm it seems LOL but need to pull it out again for a few jobs so pop back in here to find inspiration again, have been lurking through seeing some awesome works going on. but have found a quieter me :)
glad to hear your finding your happy place :)
 
This thread tickles my engineering genes . I’m thinking, without really knowing, that degree of atomization and thin lines are not technically connected but like are socially. By that I mean a company that has the engineering and manufacturing mojo to make a tiny nozzle that will finely atomize paint will also have the flow dynamics down to pinpoint cone shape.
They are two separate beast, I think. A pen with a .1 mm tip (.004”) will draw a .1 mm line with no atomization at all (until you break the tip, like right away). Also mentioned somewhere in here is how close the droplets are together. That’s actually a problem because if two droplets bump into each other they merge into one bigger. The atomization might be very fine right off the needle but without perfect air flow the meld back together.
For any given quality brush the operator must optimize viscosity, pressure, temperature, and distance for the thinnest line, which is the part I suck at. I’m also guessing that the finer the engineering is on a quality brush the tighter the limits are on operator error, making me furderer screwed☹️
 
I think you've just about nailed it. Except... It seems to me that yes the smaller the nozzle, the tighter the limits on operator error.
The finer the engineering... the more forgiving it is for a given nozzle size.
But thats also where I think it starts to get convoluted. Since I've seen plenty of people report that certain brushes simply work great with certain paint and not so much with others, even if they are quality brushes.
 
I think you've just about nailed it. Except... It seems to me that yes the smaller the nozzle, the tighter the limits on operator error.
The finer the engineering... the more forgiving it is for a given nozzle size.
But thats also where I think it starts to get convoluted. Since I've seen plenty of people report that certain brushes simply work great with certain paint and not so much with others, even if they are quality brushes.

It's not just certain paints, it's also certain colours, some colours are heavily pigmented because they would be difficult to achieve coverage with otherwise, Golden states on their website that moss green, burnt umber and most darker blues would be better through a 0.3 nozzle or larger, tgey have a chart showing the recommended nozzle size for all of their colours, but I had problems with these colours through a 0.2 with other brands including Schminke, thinning doesn't always help since thinning the paint doesn't thin the pigment and naturally overthinning usually causes a grainy effect no matter how good your atomization is or what brush you use, this is why so many if us have problems using white, I use umber a lot in my work but I usually mix my own by simply throwing a load of orange into black, I've onky used ready mixed umber once and lobbed the bottle due to the tip dry and clogging I got, still got that with my own mix but far less.

Basically brushes that claim to have excellent atomization more than likely will have but substance being pumped through them will have to capable of being so finely atomized, if they are not, can't blame the brush.

I've had my fair share of problems with airbrushes but they were bugger all to do with the brush, they were all down to tge huge breast standing behind the brush:confused: although I did once have a Harder & Steenbeck Evolution Silverline 2 in 1 that just screamed to be trashed, after six months of nothing but misery that was well and truly accomplished, as far as I know it is still in orbit to this day, if a satellite gets knocked out we'll know what caused it:thumbsup:
 
It's not just certain paints, it's also certain colours, some colours are heavily pigmented because they would be difficult to achieve coverage with otherwise, Golden states on their website that moss green, burnt umber and most darker blues would be better through a 0.3 nozzle or larger, tgey have a chart showing the recommended nozzle size for all of their colours, but I had problems with these colours through a 0.2 with other brands including Schminke, thinning doesn't always help since thinning the paint doesn't thin the pigment and naturally overthinning usually causes a grainy effect no matter how good your atomization is or what brush you use, this is why so many if us have problems using white, I use umber a lot in my work but I usually mix my own by simply throwing a load of orange into black, I've onky used ready mixed umber once and lobbed the bottle due to the tip dry and clogging I got, still got that with my own mix but far less.

Basically brushes that claim to have excellent atomization more than likely will have but substance being pumped through them will have to capable of being so finely atomized, if they are not, can't blame the brush.

I've had my fair share of problems with airbrushes but they were bugger all to do with the brush, they were all down to tge huge breast standing behind the brush:confused: although I did once have a Harder & Steenbeck Evolution Silverline 2 in 1 that just screamed to be trashed, after six months of nothing but misery that was well and truly accomplished, as far as I know it is still in orbit to this day, if a satellite gets knocked out we'll know what caused it:thumbsup:
Right on @Malky
Just to add a few more variables to the mix :)
and this is why its called art , not science
Much more than 3 or 4 variables and people start going by feel and calling it art, In reality it's just science that all us humans are too stupid to understand and adjust for perfectly all at once :)
 
Another valid point, you're not going to atomize below the size of the pigment unless you get the paint grinder option
 
From my limited knowledge, those variables would certainly have a lot to do with it. The Eclipse is a brush recommended time and time again for good reason, it’s great.
I have screwed the mix and pressure up so badly that even that fantastic brush just kind of looks at you and says “what do you want from me, I’m not a magician”. LOL.


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