There was a time when the only spray techniques a painter needed to perfect were the actual techniques of spraying, such as
distance, overlap and travel speed. These basic techniques are still critical to good paintwork, but now a painter must also
be concerned with a whole gamut of techniques that make the refinish/ repair undetectable and profitable.
Figure 1 Commercially available test panels have black and white checks that eventually become covered so the painter can
tell how many coats of basecoat are needed to achieve full coverage.
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A productive painter in today's market must be proficient at techniques that return a vehicle to its pre-collision condition.
To do this successfully, the repair must be undetectable; the finish must match the vehicle's color, metallic orientation
and texture; and the repair must be completed in as short a cycle time as possible, while keeping the material usage as low
as possible. In addition, the technician must do all this while complying with national, state and local environmental and
safety laws.
Painters, to be proficient, must master not only the physical techniques of applying paint, but also the sometimes more difficult
tasks of time and material management. In larger production shops, a lead painter must also develop leadership techniques,
which will enable the department to work as a team. Therefore, a painter's day is filled with decisions that become critical
to the overall process of restoring a vehicle to its pre-collision condition.
Today's paint technicians must regularly make several technique decisions confidently to assure a successful repair/refinish.
Is the test panel a blendable match or does the color need to be tinted? Which blending technique (standard forward blending,
reverse blending or wet bedding) is best for a particular color? Which clearcoat is best for the job, and which clearcoating
technique should be used? Should the vehicle parts be painted on-or off-vehicle? Should the repair be performed with UV products
(UV primer and clearcoat)? How can the painter complete the refinish with the highest transfer efficiency? First, let us look at the technique of a test panel. Though test panels have been around for years, not all painters choose
to use them. Some painters will instead mix the formula, stir it and then hold the stick up close to the vehicle and "eyeball"
the color. However, this method of color testing actually tells the painter very little about whether the paint will match
or not. To get accurate knowledge that a color will match, the technician must spray a test panel.
The commercially available test panels have black and white checks that eventually become covered so the painter can tell
how many coats of basecoat are needed to achieve full coverage (Fig 1). They also have space on the back for the painter to
note the color formula or its variant that was selected, how many coats of basecoat were needed and which clear was used.
For a test panel, the paint should be mixed and reduced according to the paint manufacturer's recommendations and should be
sprayed using the same paint techniques that will be used when the vehicle is painted.
After it has been sprayed, the test panel is compared to the vehicle using sunlight or a sun-corrected light to determine
if the color is a blendable match. The metallic orientation also can be observed at this point to determine which blending
method is best for this vehicle and its color. The test panel can be kept with the customer's records or the painter can keep
it in his or her personal file for future reference.
Figure 2
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With the test panel complete, the painter must next decide which blending method should be used. The standard and most often
used blending method entails the first coat of paint being applied to just beyond the repaired area, the second applied beyond
the first, and the subsequent coats being progressively larger (Fig 2). The number of coats needed to reach hiding is determined
by the test panel; though three coats may often be sufficient to cover, more may sometimes be needed. If the test panel reveals
that more than three coats are needed, the progression should likewise be adjusted. This technique is best-suited for simple
blending of coatings that do not contain large amounts of metallic or mica.
