Hummer H1 (2002+). Manual - part 159

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Body 10-7

05745159

Blind Rivet Installation

NOTE:

Ensure the proper rivet grip length is selected for each

application (Table 6). Rivets can tolerate only 0.0468 in. (1.19
mm) variation in material thickness for each particular rivet
length. For double dimpled sheets, add countersink head height
to materials thickness.

Insert rivet stem into pulling head of rivet gun or adapter.

Hold rivet gun in line with axis of rivet as accurately as
possible.

Apply a steady, firm pressure against rivet head.

Squeeze handles of manual gun. The rivet clamping action
will pull sheets together, seat rivet head, and break stem
flush with head of rivet.

Table 6: Rivet Grip

Material Thickness Range

Rivet

Grip No.

MINIMUM

MAXIMUM

Not Applicable

0.0625 in. (1.65 mm)

0.0625 in. (1.588 mm)

0.1250 in. (3.18 mm)

0.1875 in. (4.76 mm)

0.2500 in. (6.35 mm)

0.3125 in. (7.94 mm)

0.3750 in. (9.53 mm)

0.4375 in. (11.11 mm)

0.5000 in. (12.70 mm)

0.5625 in. (14.29 mm)

0.6250 in. (15.88 mm)

0.6875 in. (17.46 mm)

0.9750 in. (24.77 mm)

10-8

Body

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Aluminum Repair

CAUTION:

Body repairs should not be made using welding or

heat for forming. Heat will only weaken the material and lead
to further problems.

Material

Aluminum material used for repairs should be of the same al-
loy and temper as the original if possible. In general, 6061-T6
aluminum alloy should be used. Material thickness must be the
same or thicker. This alloy will work well for flat repairs, but is
not well suited to bending because it is quite hard and cracks
easily when bent sharply. When bends must be made, use
softer 6061-T4 aluminum alloy and increase material thickness
by at least 50 percent. As a general rule of thumb, 6061-T4 alu-
minum alloy should be bent with a minimum bend radius of
one to two times material thickness, whereas 6061-T6 alumi-
num alloy requires at least three times material thickness radius
for bends. In all cases, bends should be closely inspected for
cracks. A suitable method for avoiding bending cracks is to ob-
tain angles that are extruded from 6061-T6 aluminum alloy or
use preformed angles for repairs.

Epoxy Adhesive

Where it is necessary to remove parts, note that epoxy adhesive
is used in joints. Use care in parts removal to avoid unneces-
sary distortion. Parts should be separated by peeling action.
Before parts are reassembled, it will be necessary to remove
any remaining cured epoxy from joints so parts will fit together
with good, even contact. Use of epoxy requires special storage
and application procedures which do not lend themselves to
repair. For this reason, epoxy will not be used for repair. To
compensate for the lack of epoxy, additional rivets should be
used when making repairs to existing joints.

Rivet Patterns

Rivet patterns are denoted by rivet spacing and rivet edge
distance. Rivet edge distance is the distance from center of
rivet to nearest edge of sheet. Rivet spacing is defined as
the distance from center of rivet to center of adjacent rivet
(Figure 10-1).

Required rivet spacing is determined by strength needed in
the joint. A general feel for strength required can be
obtained by inspecting rivet patterns in surrounding areas.
Body repairs made using single rows of rivets should be
performed using rivet spacing not greater than 1.6 in.
(4.1 cm) and not less than 0.625 in. (15.9 mm). Use 1 in.
(25.4 mm) rivet spacing as a general practice for repairs.
Rivet spacing used in original construction may be greater
due to additional strength obtained by using epoxy
adhesive. Do not use rivet edge distances less than 0.375
in. (9.5 mm).

High strength joints or large area patterns may require use
of double or multiple rows of rivets to obtain sufficient
strength.

Figure 10-1: Riveting Patterns

Care must be taken to assure rivet hole patterns are
transferred accurately in cases where a part with no holes
is mated to one which already has rivet holes. Hole
patterns may be transferred using one of the following
patterns:

Lay new part in place, and use holes in mating part as
a drill template. This requires the new part to be
underneath the mating part. Care must be taken not to
distort original holes.

Use the removed part as a drill template by clamping
the old and new parts together. This requires that parts
rest flat and rivet flange be undistorted.

Joint Design

Loads are applied through a joint to fasteners that hold it
together. These loads are applied to fasteners in the form
of shear loads or tension loads. If load is perpendicular to
axis of fasteners, the fasteners are loaded in shear. The
fasteners are loaded in tension when load is along axis of
fastener, causing a pull on each end of fastener.

Rivets are designed to be loaded in shear. Do not create
any new joints during repairs which cause rivets to be used
in a tension application. Bolts should be used for tension
applications or substituted for rivets in very high shear
load applications (Figures 10-2 and 10-3).

3D 3D 3D

6-S10-025

DOUBLE ROW RIVETING PATTERN

TRIPLE OR MULTIPLE ROW RIVETING PATTERN

D = DIAMETER

OF RIVET

(PREFERABLY ABOUT

3X THICKNESS OF

THICKER SHEET)

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Body 10-9

05745159

Figure 10-2: Rivet Loads in Shear

Figure 10-3: Bolts Replacing Rivets

Repair Parts

Paint repair parts or patches with epoxy primer before
installation.

Apply sealing compound to mating surfaces to prevent
corrosion.

Install part or patch.

Paint repaired area with epoxy primer.

Paint repaired area with polyurethane as required.

Repair of Negligible Damage

Negligible cracks are repaired by drilling a small hole at
each end of crack to stop crack propagation. This is called
stop-drilling. Table 7 gives proper drill sizes for stop-drill-
ing cracks.

Negligible holes are repaired by rounding and smoothing
edges of holes to alleviate stress risers caused by sharp
notches.

CAUTION:

Never use heat to reform parts. Part strength is

greatly reduced.

Small dents and distorted areas may be repaired by
bending or hammering as long as the operation does not
cause materials to crack or tear. Sharp bends should not be
attempted.

Repair by Patching

Most body panel damage that exceeds the limits of negligible
damage may be repaired by patching. This procedure involves
removal of damaged area and application of a patch to cover
the area. The damaged area is prepared by rounding or smooth-
ing of all corners and edges to ensure cracks will not spread
into undamaged areas (Figure 10-4). In case of a large crack, it
may be desirable to stop-drill the crack rather than cut out a
portion of the panel or structural member. Repair is completed
by applying a large overlapping patch over the damaged area
(Figure 10-5). The overlap must be sufficient to allow the ob-
servance of proper rivet edge distance (.25 in. or 6.4 mm).
Large areas of damage are best repaired by attaching patch
with multiple rows of rivets (Figure 10-6).

RIVET

RIVETS

BOLT

Table 7: Stop-Drill Sizes for Negligible

Cracks

SHEET THICKNESS

MINIMUM STOP

DRILL BIT

SIZE NO.

0-0.032 in. (0-081 mm)

0.033 in. (0.84 mm) and thicker

40
30

10-10

Body

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Figure 10-4: Patching

Figure 10-5: Patching Cracked Areas

Figure 10-6: Proper Rivet Distance

Repair by Insertion

For damage that is large or more severe in nature than a crack
or hole, it is often desirable to remove damaged area, insert a
piece of material into removed area and reinforce with a dou-
bler. This is termed repair by insertion. This method of
repair is typically stronger and stiffer than an added patch
(Figures 10-7 through 10-10).

Figure 10-7: Reinforcing Damaged Area

Figure 10-8: Doubler

PATCH

DAMAGED AREA

PANEL

PATCH

CRACK

PROPER RIVET

EDGE DISTANCE

.25 In. (6.4 mm)

DOUBLER

DAMAGED AREA

MATERIAL

DOUBLER

MATERIAL

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