Specialized air drill (spot-weld

Remover)

This is a hand-held clamp-type drilling tool

designed for cutting out spot welds (Figure 3.54).

It is powered by compressed air with controllable

speeds, and has a removable cutting drill supplied

in two sizes, 6 mm and 8 mm; the depth of cut is

also adjustable. When there is a flange at the rear

of the spot weld it is supported by the clamping

action of the C-shaped arm, while the drill is cutting

out the spot weld to a preset depth, allowing

the panels to separate. Owing to the shape and

clamping action of the tool it is restricted to

removing spot welds from an open panel edge

only. Welds on panel edges which have no access

Figure 3.51Air drill (Desoutter Automotive Ltd )

Figure 3.52Angle drill (Desoutter Automotive Ltd ) Figure 3.53Cordless screwdriver/drill (Black and

Decker Ltd )

from the rear would entail the cutting of the panel

to be replaced, to obtain access for the tool clamp.

This tool could be a worthy addition to any body

shop because of its time saving over conventional

methods and its neatness of finish.

3.23 Sanding machines

Whether they are disc, belt, orbital, flat or finishing,

sanders are the most frequently used power tools in

the body repair shop.

Disc sander

This is the most popular sander. It is a powerful

machine with a hard rubber flexible pad on to

which the actual sanding disc is fastened by means

of a centre nut. This nut is threaded in such a

way that it tightens as the machine rotates, thus

avoiding the risk of a disc coming loose. Disc

sanders are driven either electrically (Figure 3.55)

or by compressed air (Figure 3.56).

The main uses of the disc sander in the repair shop

are sanding sections on panels which are either

rusted or have been repaired by planishing and

require sanding to a smooth finish in readiness for

painting; cleaning sections that need to be filled with

Hand and power tools 115

minor paint blemishes; and blending in body solder

or plastic filler in sections that have been filled.

Belt sander

This can be used for repair to bodywork, and

is extremely good on convex or concave surfaces

where access with a disc sander would be difficult.

This type of machine uses an endless sanding

belt, which is 3 in (16.1 mm) wide, instead of the

normal round disc. Some models are fitted with a

vacuum unit so that the dust is kept to an absolute

minimum in the workshop.

3.23.3 Pneumatic sander/filer

This is a dual-purpose tool for either sanding or

filing (Figure 3.57). For sanding, an abrasive paper

sheet is clipped to the tool. It has a reciprocating

straight-line action which speeds up feather edging

or filing materials and results in a smooth surface

finish. A standard file blade can be fitted to the tool’s

base to convert it into a power-operated body file

with a speed of up to 3000 strokes per minute.

Dual-action sander

The dual action (DA) on this sander makes the pad

oscillate counter-clockwise while the head revolves

clockwise, resulting in a non-repeating surface pattern

that eliminates scratches on the surface of the

panel (Figure 3.54).

Figure 3.54Selection of air tools (Consolidated

Pneumatic Tool Co. Ltd ).

From top:

Spotle specialized air drill for removing spot welds

Supa-sander (miniature belt sander)

Metal nibbler

Dual-action orbital sander

Figure 3.55Disc sander (Black and Decker Ltd )

Figure 3.56Air driven sander (Desoutter

Automotive Ltd )

solder prior to tinning; stripping paint prior to planishing

or dressing out; dressing off surplus weld

metal after welding new sections; feather edging

116Repair of Vehicle Bodies

3.23.5 Geared orbital sander/polisher

This is a multi-orbital action machine which

eliminates swirl marks and allows coarse grit

paper to be used for high stock removal rates

(Figure 3.58). On paint and fibreglass it leaves a

perfect key for primers. The multi-orbital action

reduces work surface heat generation, which is

particularly important when sanding fillers and

paint. The tool can also be used for polishing

because of its rotary gearing. It can also be

connected to a centralized or free-standing dust

collection system.

Small angle grinder

The small angle grinder (Figure 3.59) is sometimes

known as a mini-grinder or a grinderette. It is a

versatile one-handed machine, and will cut away

damaged metal, remove rust, grind down spot, MIG

and gas welds, smooth infills and generally grind

down prepared surfaces. Owing to its small size

and light weight it is ideal for grinding in confined

spaces and tight corners. These machines normally

use a hard disc for grinding.

Figure 3.58Geared orbital sander/polisher

(Desoutter Automotive Ltd )

Figure 3.59Small (178 mm) angle grinder

(Desoutter Automotive Ltd )

Figure 3.57Straight line sander (Desoutter

Automotive Ltd )

Oscillating sander

This special sander (Figure 3.60) is an oscillating

power tool, only available in this form from the

company Fein. Oscillating means that the grinding

plate – here a triangle rather than a disc shape –

does not rotate, but moves to and fro through only

2 minutes of angle at a frequency of 20 000 oscillations

per minute. This ensures high grinding

performance, with multiple contact between the

grinding particles and virtually all materials: wood,

paint, plastic, filler, metal, non-ferrous metals

and so on. With the aid of the triangular grinding

plate you can reach into any corner or inside the

narrowest of openings, for ideal sanding of edges

and profiles. Good-quality transitions can even be

obtained when spot grinding. This sander is the

ideal complement to orbital sanders, eccentric

Hand and power tools 117

sanders and other portable grinding equipment

used in a body repair workshop.

Rotex sander

This tool (Figure 3.61) can be used as a fine sanding

random orbital machine or as a rough sanding

machine; in the latter mode it can also be used as a

polisher. As part of the process of repairing vehicle

bodywork, old layers of paint can be removed with

this sander. Because of the efficient dust extraction

the sandpaper does not become loaded, and so the

It can be efficiently operated in one hand owing to

its small size and light weight, and thus may be

used to complement conventional angle grinders or

disc sanders. It can be used for the removal of

paint to reveal production spot welds, and for

dressing small plug welds or tack welds in awkward

locations such as wing and inner valances,

floor pans and inner sills.

3.24 Other power tools

Impact air screwdriver

The impact air screwdriver has a quick-change

bit holder for inserting different screwdriver bit

heads: slot, Phillips and Pozidriv (Figure 3.63). It

is ideal for removal of rusted-in screws and other

fasteners in locations such as door locks and door

hinges.

Ratchet wrench

Ratchet wrenches can have in or in drives

(Figure 3.64). They are ideally suited to a wide

variety of nut turning operations, either fastening or

unfastening. Initial hand ratcheting enables a tight

or seized fastener to be slackened off prior to rapid

runoff using the air power. Also final tightening

can be controlled by hand ratcheting after fast

rundown using the air drive.

Figure 3.61Rotex sander with full dust extraction

(Minden Industrial Ltd )

Figure 3.60Oscillating sander (Fein/George

Marshall Ltd )

Figure 3.62Miniature belt sander (Desoutter

Automotive Ltd )

transition to undamaged paintwork remains smooth

and free of scratches, thus considerably reducing

repair work.