Mitsubishi Lancer Evolution 8 MR. Manual - part 11

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CHANGING WELDED PANELS – ALUMINIUM ALLOY PANELS

(2) When hammering, note that the panels stretch easily, so use a

wooden or plastic hammer.
Note
Reduce stretching and process hardening, and do not
leave hammer marks.

2. Check for distortion

Polish with #80 ~ #120 grade sandpaper, checking for any
distortion.

3. Removing distortions

Remove any distortions Using a levelling hammer and a torch,
correct any distortions.

Note
(1) Heat to about 250˚C to do this work.
(2) Be careful when heating so as not to cause
discolouration when welding.
(3) Use a damp cloth to prevent heat increases which
could result in heat affecting heated area (distortion
etc.)
(4) Do not use drawing hammers which are used for
sheet steel, as this could result in cracking.

4. Polishing

Polish with a disk or a double action sander.

• Disk sander: #100 ~ #120
• Double action sander: #150 ~ #180

Note
Since the material is softer than sheet steel, choose a
polishing material that does not scour the surface deeply.

Repairing cuts and tears

When sheet steel panels are cut, torn, or have holes, repair using
CO

2

MIG welding. However, with aluminium alloy panels, use MIG

or TIG welder and use argon gas (inert gas) as shield gas.

Extent of distortion from welding

Gas welding (large distortion) > TIG welding > MIG welding (little
distortion).
Here we explain the MIG welding process, where distortion
resulting from welding is small.

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CHANGING WELDED PANELS – ALUMINIUM ALLOY PANELS

MIG welding procedure

1. Repairing sheet metal

These should be repaired by heating the damaged part gently,
and lightly hammering. The areas stretched by hammering out
should be cut away using an air saw.

Note
(1) Take care not to overstretch or damage the panel.
(2) The gaps at the joint areas should be as narrow as
possible.

2. Welding

This work should be done using equipment designed for
aluminium welding or equipment that can be used for both
aluminium and steel plate welding.

• Welding wire: 5356, 5556, 5183 (JIS classifications)
• Wire dia.: 0.8 or 1.0mm

(1) Remove any grease from welding areas using white spirit
or similar.
(2) Immediately prior to welding, remove any oxidation film
with a stainless steel wire brush (including the rear side), and
carry out the work immediately after cleaning.
Note
To minimize distortion and material melting and coming
away, weld a little at a time, rather than welding long
stretches.

3. Inspecting welded areas

After finishing off areas sanded with #100 disk sander, check
that there are no inadequately welded parts (red check).
Note
The panel surface should not be excessively sanded away.

4. Checking for distortions

Polish with #80 ~ #120 sandpaper, and check for distortion.

5. Removing distortions

Remove any distortions by pressing out using a levelling
hammer and a torch.

Note
(1) Heat to approx. 250˚C to do this work
(2) Take care when heating so that welding can be done
without heating causing any discolouration

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CHANGING WELDED PANELS – ALUMINIUM ALLOY PANELS

(3) Use a damp cloth to prevent temperature rising and

causing distortion or other effects in the area being
heated.

(4) Do not use levelling hammers which are used for sheet

steel as they can cause cracking.

6. Finishing

Finish off with #100~#120 grade disk sander.

Note
As spark marks and carbon adhesion can have an
adverse effect during painting, remove completely using a
stainless steel wire brush.

Other welding

1. TIG welding

The process is basically the same as MIG welding, using the
same arc welder, but instead of using an electrode wire, a rod
coated with flux is used.
To help prevent distortion from the heat generated in welding,
and poor quality welding, this job should be done by someone
with suitable training and practice.

• Welding rod: 5356, 5556, 5183 (JIS classification)
• Diameter: 1.6mm

2. Gas welding (oxyacetylene)

In essence, if gas welding can be done, then a welding rod
and flux (for cleaning and reducing oxide inclusions) can be
used.
To help prevent distortion from the heat generated in welding,
and poor quality welding, this job should be done by someone
with suitable training and practice.

• Welding rod: 5356, 5556, 5183 (JIS classification)
• Diameter: 1.6mm

(1) Flux is made to adhere by heating the welding rod.

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CHANGING WELDED PANELS – ALUMINIUM ALLOY PANELS

(2) Melt the flux with the torch, and weld, removing oxide film.

Note
The molten welding rod flows easily, so as far as possible
keep the surface being welded flat.
(3) Flux left on the panel should be removed using a stainless
steel wire brush or similar.

Finishing filler

1. Polish areas filled with filler using #150 ~ #180 (double action

sander).

2. Clean away any grease on the surfaces where there is filler.
3. Apply 2 part epoxy primer or, for a primer pre-treatment 

designed for use with aluminium.

4. Flatten down with # 180 (double action sander)
5. Remove grease and clean surface areas where there is filler.
6. Paint filler in sheet metal, and allow to dry naturally.

Note
Do not speed up by drying at 60˚C or over.

7. Polish with #180.