Aluminum - Precautions on Aluminum Alloy Panel Repair

Precautions in Repair Process
When aluminum and metal oxide (iron oxide) powders are mixed and ignited for some reasons, a strong redox reaction occurs. This is called thermite reaction and can generates heat up to 5,432 °F (3,000 °C).
Separate and ventilate aluminum work areas to avoid mixing the aluminum power with other metal powders.
Aluminum is non toxic, however due to its light weight, its particles can easily be dissipated into the air. Always use protective equipment to prevent dust from entering the lungs and eyes.
When aluminum is in contact with other types of metals (especially iron), it will cause galvanic (contact) corrosion on aluminum.
Because of this characteristic, if the tools used for steel panel repair are then used on aluminum parts, the iron power will adhere to the aluminum surface causing corrosion. Maintain a separate set of tools and work area used only for aluminum repair.
When aluminum alloy is exposed to the air, an aluminum oxide layer will be generated in a short period of time. This oxide layer can negatively impact putty and paint work, therefore basecoat treatment must take place immediately after sanding and degreasing the surface.
Aluminum is brittle and tends to crack and work harden easily. By heating, workability improves when restoring the deformed areas and work hardening and crack can be prevented. Heating is very effective during repair, however the temperature must be tightly controlled as the workability becomes the best only within a tight optimal temperature range. When the temperature exceeds this range, the aluminum’s durability is reduced.
Aluminum Sanding Precautions:
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Use separate sanding tools and coated abrasives for aluminum repair.
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Use lower sanding tool speeds to reduce heat tool and avoid continuous heating work.
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Do not use clogged sanding tools or coated abrasives.
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Use only stainless wire brushes, never use a regular steel wire brush.
Aluminum Welding Precautions:
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Clean the repair area before welding.
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Confirm welding conditions using a test piece before making actual welds. Do not start the welding arc on the joint surface.
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Do not use a welding wire without referring to the information in the model specific body repair manual.
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Use only 100% argon shielding gas.
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Welding wire must be stored in a dry, temperature-controlled area inside a closed container. Do not use wire that has been stored for a long time.
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Do not use an oxyacetylene gas torch for welding or soldering.
Aluminum Metal Work Precautions:
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If cracking is observed in the buckled area of structural components, replace the parts. Do not attempt repair.
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The buckled area of 5000 grade aluminum parts must be straightened using heat within a tight temperature range. Do not cold straighten this type of aluminum. Do not repair damaged aluminum castings.
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Do not clamp tools directly to the aluminum.
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Do not use a file-faced hammer.
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Do not solder aluminum parts to repair them.
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Always apply epoxy based primer before putty application.

Aluminum Assembly Work Precautions:
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Only use specified screws and bolts.
Aluminum Inspection Precautions:
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After straightening and welding work on the structural parts is completed, make sure to check for cracks.