Thread: What makes paint go through one airbrush and not another

Hi,

I have some gesso based paint that thinned with some acrylic paint medium goes through my old airbrush ok but even the thinner wont go through the new one. Obviously this paint wasn't designed to be airbrushed.

The one that works is a pasche V side feed 0.25mm nozzle.

The one that doesn't iwata HP-C+ gravity feed with 0.30mm nozzle.

Can anyone explain why? I am assuming it's because of the different feed systems. Maybe i should of bought a different iwata. Do you think a eclipse or revolution would be better?

Thanks in advance

The only gesso I have ever used is water based, try thinning it with distilled water instead of the acrylic medium, and thin it to a milky consistancy. You may want to strain it through a piece of stocking material before ya use it too.

For those that don't know what it is; Gesso is normally fairly thick, and it's used as a filler/basecoat for canvas's. It's made to let you build up a thick, sandable surface to paint on. You can thin it down a bit, but going too thin will destroy the bonding agents within it.

As far as why it will work in one brush and not the other, my guess is that the Iwata you are using needs a good cleaning. The Revolution and Eclipse lines of brushes are just that, different model lines, they aren't a specific model or feed type. The Iwata you listed is a gravity feed brush, so you need to be extra careful in making sure your gesso is well mixed BEFORE it goes into the brush, and I would only put a small amount in at a time. It probably won't stay mixxed for a long stretch of time, so if you only put a little in your brush, and keep the rest in a bottle you can shake up on a regular basis, then you will probably have better luck spraying it.
I would use whatever the manufacturer of the paint/gesso reccomends for reducing it.
Most Gesso brands have you reduce it with distilled water as KD suggested, but it's always best to follow the instructions, it helps eliminate the variables if you have problems or issues.

I don't know that I have ever heard of a "Gesso based paint", but you learn something new every day.

Thanks for that.

Indeed that is just the problem i was having, thinning with to much water and there was not enough of the bonging agent for it to set properly. The manufacturer kindly helped me with what to thin it with(their binder medium) I will pull apart the iwata and give it a good clean.

I thought maybe a siphon feed sucked the paint with more force.

The paint is Matisse Derivan - Matisse Background if you are interested. I've had great success using it as a coloured primer on my models. Just not through the iwata! It's such a great brush though that i have no idea how a custom micron could be better!!

Pulling it apart did the trick. Clean but i found out about the thing at the end of the airbrush to adjust how far you can pull it back. It was wound way forward. Just wind that back and i can't believe the shear volume of paint that will go through it.

Glad you figured it out. The preset handles are great for repetitive work, but you do need to keep an eye out when you start doing any adjustments.