Refinishing Polyurethane And Lexan Parts - Pontiac Grand Prix Service Manual

FRONT A N D REAR
BUMPERS 14-15
4.
Fill the repair area with the mixed compound to a
height slightly above the surrounding contour. Work out
air bubbles, if present.
NOTE: Thinly spread the remaining mixture on a clean,
hard surface to lengthen pot life. 2%is may be used later
on the curedpatch for repair ofpin holes.
5. Place a heat lamp approximately 15 inches from the
patched surface for 15 to 30 minutes, or until the
repair material will not transfer to the touch.
6. Remove the heat lamp and allow the patch to return
to room temperature. The repair mix
will
harden with
cooling.
7. Dress the patch to contour with a cwed-tooth body
filt, followed by sanding with #220 sandpaper and
block.
CA UTION: The cured repair material is slightly harder
than t k original foam and may easily be undercut.
8. If the patch is uneven or porous, repeat steps
4
thru
7.
REFINISHING POLYURETHANE AND LEXAN
PARTS
Refinishing the patched area amounts to no more than
a standard paint procedure. Under no circumstances,
however, should regular paint materials be uscd in
refinishing this bumper. As mentioned earlier, the
glaze coat, color coats and clear top coats that are to
be used are specially formulated with an elastomer
vehicle so that the cured film may bend under impact
without cracking or splitting. This procedure is to be
uscd on GTO front bumpers, Pontiac front bumper
center extension, Bomeville rear bumper applique,
and Firebird front bumper.
Material:
Glazing Compound
Color
Top Coat Clear
Thinner
#220 and #400 Sandpaper
Equipment;
Suction Spray Gun with same nozzle and air cap
combination used for acrylic application
1. Featheredge the repair area by dry-sanding with
#220 sandpaper followed by #
400
grit sandpaper.
2.
Thoroughly m i x the glazing compound and
spray-apply the material in the same manner as PX
primer-surfacer. Apply two or three coats, allowing
flash-time between coats.
3. N o w 15 to 30 minutes drying time at room
temperature. When dry, water-sand the glazed area
with #400 sandpaper. Block-sand for maximum
leveling.
NOTE: Dry-sanding clogs the sandpaper due to the
elastomer-type vehicle
used
in the compound.
4. Re-clean the repair area with a final solvent wash.
5. Thoroughly stir the color and apply in sufficient
quantity to achieve hiding only--one dry coat followed
by a wet coat.
NOTE: If mottling occurs, the metallic color control
method of color application corrects this problem.
6. Blend the perimeter of the patch with the special
thinner provided with the material. Use standard
blending techniques after each color coat.
7. Allow the color to dry 5 to. 10 minutes at room
temperature.
8. Thoroughly m i x and apply the top coat clear, using
two coats as done previously with the color.
CAUTION: Wet application of clear coats causes
considerable darkening of the color.
Wetness of clear coats is dependent upon the amount of
color-darkening required to achieve a match. I f
application of clear coats over a spot repair creates
an
objectionable mis-match, the entire bar may be coated
with clear material.
9. Air-dry of the clear coats require 8 hours at room
temperature. Force-dry is recommended for 112 hour
at 150"-170°F.
10.
'
Compounding reduces the gloss, for this reason,
rubbing compound should be uscd only if a reduction
of gloss is desired.
NOTE: In using this material, the following cautions
should be noted:
. .
.
All the bumper refinishing materials are packaged at
spraying viscosity. Only
if
"veiling" occurs during
application will additional reduction be necessary.
. . .
Reduce these refinish materials with the special
thinner only--never use acrylic thinner.
. . .
The top coat clear material has a tendency to yellow
if
subjected to prolonged elevated temperatures (3OVF).
. . .
The clear coat tends to sofin the color over which it
1 3 applied. For this reason, premature featuring (within
24 hours) o f air-dn'ed fth,
as
in overlap of a
I C Y ~ O ~ L P ! ~
repired area,
will
TEAR
and PEEL the co r
08
the
.nvfie.
6