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.
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