Bubbling
in the color reservoir is caused when air is misdirected into the color
channel rather than “jetting” over the paint tip in a manner that pulls
or “vacuums” the color/media from the airbrush. The air enters the
color passage causing a bubbling in the color reservoir - like when you
blow into a straw in a glass of milk, causing the milk to bubble in the
glass.
Generally there are four common causes of air entering the color channel
causing bubbling in the color reservoir:
1. non-sealing of the paint
tip threads (threaded paint tip nozzles) or a non-sealing of the paint
tip against the angled recess of the airbrush body (non-threaded drop in
paint tip nozzles). Air goes behind the paint tip and into the color
channel.
2. partial clog of the paint tip - preventing the proper pull
of paint from the paint tip.
3. incorrect spray regulator alignment
pushing the air into the paint tip rather than across it as necessary to
“vacuum” color out from the paint tip.
4. split/fractured paint tip -
air enters the paint tip through the fracture and goes back into the
color channel.
The
key to remedying bubbling in the color reservoir is to determine which
of the four causes is occurring and correct it. The remedy of cause 1
is to seal the paint tip threads with heated beeswax or, in the case of
drop in paint tip nozzles - be sure there is a complete sealing of the
paint tip against the recess of the airbrush body it sits in. Check the
recess for minute paint particles and/or scratches. If this surface is
scratched, the scratch can sometimes be filled by rubbing Chapstick
into it. To remedy cause 2, disassemble and inspect the paint tip
making certain it is clear, including cleaning inside the paint tip,
from its backside, with a soft micro-brush. DO NOT FORCE ANYTHING
THROUGH THE PAINT TIP. To remedy cause 3, make sure the spray regulator
is properly tightened on to the nozzle head. Also inspect and clean
the back side of the spray regulator with a pointed cotton swab. To
remedy cause 4, replace the paint tip.
(Reprinted from "Ovespray" the Badger Airbrush newsletter).
