•
Viscosity
is a technical term used to indicate the thickness of a liquid. Having the correct viscosity
of paint is important to ensure the paint atomizes correctly and sprays well, giving you a good-
quality finish. If your material is thin like water then the viscosity is said to be low, while if thick like
latex interior paint, then viscosity is said to be high.
• You should always test the viscosity (or thickness) of paint before spraying to see if thinning
is required. The correct viscosity is not too high or low, and it is important to ensure the paint
atomizes correctly and sprays evenly.
Before spraying, the material being used may need to be thinned with the proper solvent as
specified by the material manufacturer. Follow the instructions below.
1. Stir the paint or other spraying material thoroughly before measuring the viscosity.
2. Dip the viscosity cup completely into the spraying material.
3. Hold the cup up and measure (in seconds) the time it takes to empty the liquid out of the cup. This
time is referred to below as
RUN OUT TIME.
If the
RUN OUT TIME
is higher than indicated on the
table on
Page 8
, refer to the instructions in the
THINNING
section on
Page 9
.
Material to be sprayed should always be strained to remove any impurities which may enter and
clog the system. Impurities in the paint or other material will result in poor performance and a
poor finish.
MATERIAL PREPARATION
THINNING CHART
Material Run out Time (Sec)
1) Oil enamel
2) Oil based primer
3) Oil stain
4) Clear sealer
5) Polyurethane
6) Varnish
7) Lacquer sanding sealer
8) Lacquer
9) Automotive finishes
10) Latex
25–60
30–60
No thinning required
No thinning required
No thinning required
20–60
25–35
25–35
20–40
45–60
7
8
