Atomization
The breaking up of finish particles through
the tip of an air gun under pressure. A fine mist is created that lands on the
surface and levels out to a smooth finish.
Binder
Finish or resin added to the stain, used to
lock the pigment and dyes into the wood.
Blush
Cloudy haze in finish caused by moisture
trapped beneath the surface. High humidity is the most common cause. Can be also
caused by the improper application of an oil base stain under a water base
finish.
Coalescing
The evaporation of the chemicals that keep
the acrylic resin in a liquid form. Once this process is complete, the acrylic
forms a hard finish film.
Crazing
Tiny cracks in the finish film, usually
along the edges of a surface. Caused by the finish drying too fast in high
temperatures.
Extender
Chemical additive used to control the drying
and flow of water base finishes. Can be used with stains and finishes to
"extend" the open time.
Fish Eyes
Defects in the finish film caused by surface
contamination (usually from oils, silicones, and waxes.)
Gloss
The amount of light reflected off the finish
surface. High gloss is rated 80-90° . Semi gloss is rated 50-75° . Satin is
rated 30-45° . Rubbed effect is rated 20-25° . Flat sheen is rated 5-15° .
Grain Raising
Tiny fibers in the wood grain that lift when
exposed to water. Easily controlled with proper sanding.
HVLP
(High Volume Low
Pressure). An HVLP spray unit consists of a turbine motor that produces warm,
low-pressure air. Its high transfer efficiency increases the square foot
coverage.
Orange Peel
Defect in finish film
usually caused by cool drying temperatures or improper fluid tip size. The
finish looks like the surface of an orange.
Pinholes
Small defects in
finish film caused by surface contamination. Resembles tiny holes in the finish.
Resin
The material that
forms a hard film on the surface after the chemicals have evaporated. Acrylics
and urethanes are the common resins used in water base finishes.
Satin
Finish that has had
the gloss reduced to provide a softer sheen. A flattening agent made from fumed
silica reduces the amount of light reflected by the surface.
Stain
A liquid mixture to
color wood. Made of 4 parts: Vehicle (water or solvent), Colorant (pigments and
dyes), Binder (resin), Additives (solvents to control drying).
Viscosity
The thickness of a
fluid. This is used to determine flow rates for spray application. Usually
measured with a #2 Zahn cup or #4 Ford cup. Viscosity can be decreased by using
the appropriate thinner.
