Glossary of
Finishing Terms
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.
