Best type of airbrush for metallic paints?

Either one would work fine with metallics.  The only thing you would watch out for with metallics is the needle/nozzle size as the pigments tend to be bigger and could block up the tip.  (not a real concern because anything .3mm or over should do fine with them) 

The only thing that would differentiate between a siphon fed or gravity fed is how much detail you foresee yourself wanting to get with the airbrush.  the gravity fed is more adept at fine detail than a gravity fed due to the lower airpressure requirement.

So basically most airbrushes that shoot model paints will also shoot metallics.

Tom,

Thank you for your answer. Looks like the tip size is the key issue.

Mike

Technically, it's the size of the pigment in the metallics that causes the problem.  The needle of an airbrush fits into the nozzle and effectively seals it when the needle is completely closed.  When you pull it back to allow paint to flow you are barely opening a crack between the needle and the nozzle.  The particles in some metallics (as well as some other large-pigment paints) are just too large to fit through the crack.  Thinning won't help because it's the actual pigment particles themselves that are too large.

Two things you can do:  1) Spray at a lower pressure.  This allows you to pull the needle farther back for a given volume of paint flow, thus making the "Crack" a little bit bigger.  2) Use a larger nozzle . needle combination.  Some airbrushes only have one head assembly available, others have several to choose from.

I had problems with Alclad until I reduced my pressure to about 8 psi and that made a world of difference.  At that pressure my airbrushes are basically wide open and the paint flows very well.

mass tactical wrote:

Tom, Thank you for your answer. Looks like the tip size is the key issue. Mike

not so much the tip size, as MOST airbrushes will shoot metallics well..  like Scott said, it's all in how you approach shooting them, as well as the brush itself

basically the Iwata HP-CS and HP-CR, any of the Omni's, and all of the Badgers except the Sotar and possibly the 100LG with the fine tip/needle would do well with metallics... also all of the Paasche's Vegas etc would work... I would be cautious about using an Aztek with Alclad though because of the plastic tip, shooting through a lacquer based paint might mess it up. 

Don't you have to keep swirling the jar to keep the metallic pigments from settling?
I have heard that a siphon-feed with a jar is better because of this but have not tried it personally.

I don't have issues with my Badger 200G using a medium tip/needle combo.  I tend to use Metallizers, have Alclad but haven't used it yet.

MikeV, just as a note, I haven't noticed a difference between my gravity feed and my siphon 200 in this regard.  I tend to swirl once in a while as I paint anyway, just out of habit.  I also tend to jog the needle a bit now and then, too.  Habits from illustration classes, using inks.

Don't you have to keep swirling the jar to keep the metallic pigments from settling? I have heard that a siphon-feed with a jar is better because of this but have not tried it personally.

I haven't tried that either, Mike.  I normally just put a few drops of paint in the brush, enough for a single coat, and blow out my airbrush with laquer thinner in between coats.  For subsequent coats I shake up the bottle and start from the beginning.  Metallics do settle out very quickly so that does make a lot of sense.

Thanks guys.
I don't think swirling the paint in the cup applies near as much with Alclad.
I think it is more of an SNJ spray metal thing that I read once.

Chimera wrote:

MikeV, just as a note, I haven't noticed a difference between my gravity feed and my siphon 200 in this regard.  I tend to swirl once in a while as I paint anyway, just out of habit.  I also tend to jog the needle a bit now and then, too.  Habits from illustration classes, using inks.

Same with me picking the paint from the tip with my fingernails which is a T-shirt airbrush artist's trick that has always stuck with me.