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sidefeed vs gravity

Discussion in 'Airbrushes' started by amrogers3, Nov 1, 2018.


  1. amrogers3

    amrogers3 Young Tutorling

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    Ran across a post a few days ago I found interesting regarding side vs gravity feed. I will spare you from reading the entire quote but Vladimir is saying sidefeeds spray better because you need less paint reduction therfore more saturated and less spidering. Is this true of sidefeeds?

    I see miniature painters always using gravity feeds but maybe I should be looking into a sidefeed. Would like to get you more experienced people's thoughts.


    Short version

    Full version
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  2. Robbyrockett2

    Robbyrockett2 Air-Valve Autobot! Very Likeable!

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    Mmm, this varies from brush to brush to brush. Not to mention paint type. Switching paint can actually make the opposite true.

    My side feed needs more reduction with most CI colors but it has finer control of flow.
    Yet it runs wicked about the same as gravity.


    Without going into details I'll say that this is one of those things that is a very fine difference that will only be noticed by skilled and practiced individuals and is unlikely to make any difference for a newer person.

    While funny enough is also something easily adapted to by anyone with enough skill to notice.

    So
    The difference in line of site is a far more obvious and dividing feature for most people.
    Last edited: Nov 1, 2018
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  3. Leakyvalve

    Leakyvalve Mac-Valve Maestro! Very Likeable!

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    Depending on the configuration you might get close to equality but in general I don't think you could scientifically say a sidefeed is better than a gravity for reduction or paint flow.

    You can get gravity side feed cups, and you can get side cups that would allow enough paint in them to be above the siphon line. But that's as close as you will get, IMO.
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  4. Robbyrockett2

    Robbyrockett2 Air-Valve Autobot! Very Likeable!

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    I will say
    Siphon feeds are easier w paint that's prone to settling out.

    Otherwise feed configuration is usually decided on by factors other than paint behavior entirely
  5. DaveG

    DaveG Detail Decepticon! Very Likeable!

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    I have read plenty of reports where people will claim one type has the advantage over the other, even from some very experienced professionals. I have a rather large collection with which I am constantly testing, and I can find no real difference between them on a purely physical basis. The paint is drawn from the color/paint reservoir from each style of feed by exactly the same mechanism. Once the paint has a chance to fill the paint channel, surround the needle - you could empty any remaining paint from each of them, and they would continue to spray exactly the same way they did until you depleted the paint remaining in the brush.

    It comes down to a personal preference, whether perceived or not...
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  6. JackEb

    JackEb The Dragon Hunter Staff Member Admin

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    it comes down to:
    some look straight down the brush and dont like gravity feeds because it blocks the view of the needle,
    - I've never painted that way so for me its not an issue.

    Some dont like side feeds because they feel off balanced with the cup is off to one side,
    - again, i've never noticed that much of a difference for it to strike side feed from my inventory.


    just to add some confusion for (sorry in advance)
    I have an Iwata Custom Micron B cup (version 1) and Iwata Custom Micron Side feed (version 2) both have the same needle size.
    I can spray Createx Illustration unreduced in my side feed, but if I switch to the B cup (same paint, hose & Compressor setting) I need to reduce the Createx Illustration. It makes absolutely no sense, it shouldnt make any difference at all, but it is what it is !
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  7. Robbyrockett2

    Robbyrockett2 Air-Valve Autobot! Very Likeable!

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    See, now they aren't even close to the same brush but I can just about run CI straight in my 270 with .2 nozzle 3:1 p:r will do , but i need at least 1:1 reduction to get it going on the model a which I guess is around a .3

    Tons of other factors there but still just to illustrate it's more of a brush to brush thing.


    Doesn't really matter since I now typically run CI at 1:3 or 1:4 p:r anyhow in actual use and spiders are a super rare occurrence I think for most of us once we get a decent level of control.

    In any case ...you can't buy your way out of practicing.
    Last edited: Nov 2, 2018
  8. jagardn

    jagardn Airbrush Acquisition Disorder Patient Elite Member!

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    I’ve never understood the “straight down the barrel” argument. You can’t look straight down, the trigger and your finger are in the way. Your view is always from top right or top left depending on your dominant hand.
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  9. Vladimir

    Vladimir Detail Decepticon! Very Likeable!

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    @JackEb and @jagardn you're both right in your ways, for @JackEb says about both of positions while painting and @jagardn says only about position while sitting and painting. I never did any painting sitting, only standing at the easel. So side feeds and bottom feeds are preferred, but I also like old C cups.

    Concerning the paint reduction and type of paint. I use automotive urethanes. They all come very thick for using in AB and definitely for side feed I need less reduction for expected work of the brush, that gives some better properties over highly reduced paint (already mentioned). I've tried some waterbased AB paints, they're thinned down to the state where I can't tell the difference between spraying, I don't like how they are reduces. I mean AB paints are already very thinned down (can't say about CI, haven't tried it).
    I'm not agree that the paint behaves the same in both types of feed (gravity&siphon). In gravity cups highly reduced paint pigment saddles down quick and goes to the nozzle in this state, while in siphon types paint goes to tubes where the paint flow ''mixes" and then goes to the nozzle.

    One thing about the cup types. Very big difference when you paint the models and when you do detail illustration work. In model painting very high response of the trigger does not matter, while in illustration freehand detail work it's the first thing of importance. Side feed has better response from my observation.

    All been said is my observation of my type of paint from my own experience and concerns freehand detail work. For working with background painting, painting models and painting freehand a vein in the eye of realistic portrait are totally different stories.
    For those who search for better type, you can buy different airbrushes and choose what works best for you;) Some people hate side feeds, I like them. The truth is in what works for you:) I haven't yet found better brush for detail work than CM-SB, for instance.
  10. Robbyrockett2

    Robbyrockett2 Air-Valve Autobot! Very Likeable!

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    CI is kind of similar to over reduced automotive paint in that it has very little cohesion and a fairly high amount of settling. Like chalk in alcohol.

    I'll add though...consider the container shape.....

    Even with spray guns when I shoot heavy metallics I like to use siphon guns.
    Partly because anything settling is not all funneled into the pickup tube at once. So any flat area that allows some sediment to sit rather than go right into the paint path I think is a factor , maybe more so than any "mixing of the flow"...?

    I guess you would need a side feed cup with a sharp funnel that came all to a tube on the bottom with no space for settling away from the pickup to test that Theory.

    Though I have seen the telltale clean v shape area that leads to the pickup on the bottom of a cup with a bunch of sediment everywhere else that doesn't get picked up.
    Last edited: Nov 2, 2018
  11. Vladimir

    Vladimir Detail Decepticon! Very Likeable!

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    Good to know. I'll consider this as I think maybe for some reasons some certain works and conditions may require WB paint. But honestly, I don't like WB. Fortunately, I have a space where to use urethanes.

    The same here. I like siphon cups. I've painted recently some (big and long) steel construction parts for the studio using bottom cup siphon gun. For this type of work it's great, I mean for many positions it works, especially from the bottom, where it's not possible to use gravity gun. Besides, it's great for primer's viscosity. Fast work and fast covering we have with this type.
    And I also like side feed spray guns RG3, W-101 and working on modification of another type (full size side feed with some extra cookies).

    BTW, for heavily pigmented custom paints (like flakes etc) there's agitated side feed type. I have it, but haven't used for that kind of paint yet.

    It seems what you describing is implemented in iwata side funel siphon cups.

    In reality people choose what's the best or what they think the best for them, no matter what the scientist would say:)
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  12. Robbyrockett2

    Robbyrockett2 Air-Valve Autobot! Very Likeable!

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    Not at all. Iwatas side cups have about an 8mm flat bottom and pigment often settles in the cups bottom without being picked up.

    I mean something where the funnel comes all the way down to the tube diameter and the tube would be at bottom.
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  13. Vladimir

    Vladimir Detail Decepticon! Very Likeable!

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    These were manufactured by Paasche long time ago when we were not even planed:) Those cups were not impossible to clean normally.
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  14. Robbyrockett2

    Robbyrockett2 Air-Valve Autobot! Very Likeable!

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    I just mean with something like that you could tell whether setlling area makes a difference.
  15. Vladimir

    Vladimir Detail Decepticon! Very Likeable!

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    It can possible to make the experiments to be sure from practice, but I don't have any wish to make this kind of experiments:) Side cups are OK and I don't need more now.
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  16. Robbyrockett2

    Robbyrockett2 Air-Valve Autobot! Very Likeable!

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    They are all fine w me.
    Other than I'm not detailing with a bottom feed.
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  17. crewchief227

    crewchief227 Needle-chuck Ninja Very Likeable!

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    I use my CM-C+ & CM-SB interchangeably everyday. The side feed has more of a pen like feel, and thus better for the majority of my detail work, but the gravity feed is more versatile.
  18. Squishy

    Squishy Queen Clown Slayer Mod

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    I never subscribe to the line of sight thing either. And I'm not sure one out performs another, but that one suits an individual more than another because of how comfortable they are holding it, and the way they like to paint, what they are painting on etc, etc. I prefer gravity because I don't like the balance of side feeds, I don't like to use a lid on the cup (I like to see the paint, notice if it gets low or starts to bubble) and don't want to adjust the cup angle all the time - especially on curved surfaces like tanks. A side cup is actually an advantage there I know, but I'm odd, and don't like it lol. I don't have to think about the gravity cup, it's just there and I can use it at lots of angles as long as it's not full. I also have a feeling of the side cup getting in the way, which many people don't have, but like I said I'm odd lol. I know I have painted some odd shaped bike frames, or other custom parts, I wouldn't have got into the corners of as closely with a side feed.

    The obvious advantage is that you can have several cups on the go with different colours for quick changes, but for me that doesn't outweigh my comfort level a using gravity fed brush.

    I feel it's more of a preference thing than a performance thing. But even if I'm wrong (as usual lollol) if you aren't comfortable, you won't get the best performance out of either type of brush anyway.
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  19. Nessus

    Nessus Gravity Guru

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    I've got 2 side feeds and 3 gravity feeds. The only difference in spray dynamics I've noticed is the gravity feeds seem to have a slightly lower minimum air pressure. But it's not a huge difference: maybe 5 psi at most, and that's in the 5-10 psi range, whereas I usually operate in the 20-25 range for most things.

    For all I know it's also possible that difference could be more a matter of properly fine tuned reduction, and my kung fu just isn't quite there yet.

    I prefer the side feeds as they typically have shorter front ends (feels a better for control: more pen-like), and allow for simpler color switching. I've never really understood either the viewing angle thing or the balance thing. As others have noted, viewing angle tends to naturally be more from a 45 degree angle than straight over the top (even when painting on a vertical substrate while standing, in my experience). And my experience has been that side feeds only feel asymmetrically balanced when unconnected: when in use, even a light hose with minimal fittings provides a strong plumb/keel effect that completely eclipses the weight of the cup. Plus Iwata side feeds in particular can natively accept the feather-light Aztrek plastic cups, and with those the effect on balance is nigh unnoticeable even when the brush is unconnected.
  20. Nessus

    Nessus Gravity Guru

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    Depends on the type of model. For stuff like tanks, planes, spaceships, or railroad (or gaming) scenery, you barely even need a double action. Still worth using one IMO, as in my experience they have better atomization than external-mix brushes.

    Figure kits are a different kettle of fish. The smaller the figure, the more an illustration-style brush helps.

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