Gravity Feed Airbrushes

[rossjr]

I ahve used airbrushes for decades, but only recently have I started trying to use a Gravity Feed for certain applications. I have run across one problem I don't seem to be able to solve, that is when I start spraying I get a splat and then it is pretty fine until I stop and start again. I have tried adjusting the air and thinning out the paint but it doesn't seem to get me anywhere.

Suggestions? Maybe some genreal comments about paint thickness and air pressue. For the record I have had this issues with both a Sotar 20/20 and Badger 360.

Thanks!

[Joseph C. Brown]

I tried using one (the Sotar that Erin now has) but I had learned how to airbrush with siphon feeds, and thus, had aquired certain habits.

Like rotating the airbrush around, under, and to the sides of a project.

However, top-loading cup airbrushes, when moved thusly, drump paint on your jeans. After ruining two pair of jeans, I regressed to using the siphon-feed brush.

But, back to your question. 8) You might check the following items:

Acrylic paint or enamel? Or other?

The brushes have good, clean, straight & undamaged needles?

High humidity within your painting area?

Using a moisture trap in your air supply line?

Strained your paint after mixing it well?

Ter (or Erin) can ya'll think of anything I missed?

[Romulan Spy]

I ahve used airbrushes for decades, but only recently have I started trying to use a Gravity Feed for certain applications. I have run across one problem I don't seem to be able to solve, that is when I start spraying I get a splat and then it is pretty fine until I stop and start again. I have tried adjusting the air and thinning out the paint but it doesn't seem to get me anywhere.

Suggestions? Maybe some genreal comments about paint thickness and air pressue. For the record I have had this issues with both a Sotar 20/20 and Badger 360.

Thanks!

One trick that I've found usefull for any dual-action airbrush is to keep the trigger pressed down at all times; keep a steady flow of air through the brush to keep the pressure constant. Use the rocking motion of the trigger to start and stop the flow of paint. If I do need to stop spraying altogether, I'll resume spraying off the model (usually on a scrap piece of paper), pull the trigger back just a bit to clear out any build-up of paint on the tip, let the trigger move forward to stop the paint flow, but keep it pressed down to keep the air flowing, point the brush at the model and gently pull the trigger back to start the paint flow.

Also, with a gravity feed brush you can use much thinner paint at very low pressure. With my fine-tipped Badger 100SG I'll make the paint very thin and spray at around 5-10 psi.

[TER-OR]

All good suggestions thus far.

It sounds like you may need to thin the paint a bit more, too.

One big problem I've noticed with the detail brushes is buildup on the exposed needle. That causes all kinds of mischief. I keep a soft brush and cup of water near the workspace and constantly clean the tip.

Play with the pressure a bit, and very gradually introduce paint to the airflow. You'll have to experiment to figure out how it will work best for you.

[Mark Yungblut]

I agree with Ter. If the problem happened with two different brushes then you need to play with the airpressure and how thin the paint should be. Try low pressure and thin the paint more. Rememberr also that gravity feeds are generally intended for super fine line work etc. Back in my technical illustration days, I uded a gravity feed for detail work using inks which are really thin. I had the pressure really low like 15 to 20 psi.

Cheers,

Mark

[rossjr]

Their is no doubt in my mind it is definately operator error, like Joe I've been a life long syphon tube bottle user so I am sure this is just somethig else to get use to. I guess what I am look for though is some generalizations like:

Gravity vs Syphon - For Gravity paint should be thinner and less air pressure than Syphon, would that be correct? Just want to make sure I am headed in the right direction. The only thing I wasn't sure about is the thinner part, I can see where less air pressure would be better.

[Mark Yungblut]

The best thing to do is experiment. I always keep some white card stock handy to practice on prioir to applying paint to the model. Try a variety of thining and air pressure till it works different brushes react differently to tthe air and paint variables.

Cheers,

Mark