MOTOR TRUCK SERVICE MANUAL
BODIES AND CABS
down excessively. To minimize grinding, the plastic putty
8. After the repair hardens, remove the plastic sheet
or fiber glass patch or fill can be smoothed very nearly to
and where necessary, apply plastic putty to bring the
the surrounding metal surface level.
The use of
repair up to the level of surrounding surfaces. Follow
polyethylene sheeting over the new patch will impart a
the instructions under "Plastic Putty Repair" when
smooth surface to the plastic or fiber glass. Apply the
using the plastic putty.
patch or filler as follows:
9. Lightly sand the area repaired--then paint as
Plastic Putty Repairs
NOTE: Avoid the excessive use of power driven grinding
discs or wheels on aluminum cab surfaces. Careless
1. Remove all old paint from the area to be repaired.
use of these tools can quickly cut through or thin down
Use paint remover or fine sandpaper. Avoid the use
the cab skin.
of a power driven emery wheel or disc. Do not use
files on the aluminum surfaces.
PREPARATION OF ALUMINUM FOR PAINTING
2. Clean the area to be filled. Wipe off loose paint or
Cleaning and Painting
3. Apply a sufficient amount of plastic putty to fill the
dent or depression.
The most important step in obtaining satisfactory
4. Place a piece of plastic sheet (polyethylene) over the
paint adhesion is that of proper surface preparation. In
every case, the surface to be primed or painted should
5. Using a straight edge or edge bent to match the
be cleaned free from all oxide, scale, dirt, grease, oil and
surface surrounding the repair, strike off the filler.
moisture. Prepare unpainted aluminum surfaces as
Use a light pressure on the straight edge working the
filler down to the level of the surrounding surface.
1. The chemicals used in this process may discolor top
The polyethylene sheet between the straight edge
coat enamels. All adjacent enamel finish should be
and filler material can be left in place until the filler
protected from direct exposure to the chemicals by
masking with paper or polyethylene sheeting.
6. After the repair hardens, lightly sand the repair to a
2. Dilute "Alumiprep #33" with Z parts of water before
feather edge and paint.
using. Use a plastic, porcelain or glass vessel.
3. Freely apply the diluted Alumiprep #33 to the
Fiber Glass Repair
aluminum surface by swabbing with a brush, mop, or
cloth, Swab surface for about 30 seconds, Re-apply
Where larger dents are to be filled, fiber glass cloth
Alumiprep and swab for an additional 30 seconds.
or fiber glass mat can be used. If this is required,
Flush away the spent Alumrniprep with clean water or
proceed as follows:
wipe with a clean wet cloth.
Wring cloth free of clean water and rewipe. Then wipe
1. Remove paint from area to be repaired.
with a clean dry cloth.
The paint must be removed well back from the area to
4. Apply undiluted "Brush-On Alodine #1201" to the
be covered with fiber glass since fiber glass will not
metal surface, brushing or swabbing the surface for
stick to painted surfaces.
about 30 seconds. Re-apply Alidone #1201 liberally
2. Wipe the area to be repaired with clean cloth to
and allow to remain for a minimum of 2 minutes. DO
remove loose paint or dust.
NOT ALLOW THIS MATERIAL TO DRY ON THE
3. Prepare the resin mix according to instructions
METAL SURFACE. Flush the surface with cold
furnished with the fiber glass kits.
water or mop with a clean wet cloth.
4. Cut a piece of plastic sheet (polyethylene)
5. Allow the surface to air dry. DO NOT WIPE DRY.
considerably larger than the repair area.
The treated aluminum surface should now have a
5. Prepare a patch consisting of fiber glass cloth or mat
saturated with resin and of sufficient quantity to
6. Apply one light coat of zinc chromate primer. The
nearly fill the repair.
first coat of primer may be lightly sanded if a second
6. Place the patch mixture on the plastic sheet and
coat is to be applied.
position the mix over the indented area.
7. Using a straight edge, smooth the patch mix to fill
the depression. Leave the plastic sheet in position
1. The processing materials are acidic.
until the fiber glass hardens.