WORK NOTICES AND PRECAUTIONS > PRECAUTIONS FOR REPAIRING ALUMINUM ALLOY PANELS |
PORTIONS WHERE ALUMINIUM ALLOY PANELS ARE USED |
![]() | Al-Mg-Si Alloy (6000 series) |
WORK SAFETY |
![]() | Dust mask (Disposable type) | ![]() | Dust mask (Exchange type) |
![]() | Face protector | ![]() | Safety glasses |
![]() | Safety shoes | ![]() | Ear plugs |
![]() | Ear protectors | ![]() | Cotton gloves |
![]() | Solvent gloves | - | - |
DIFFERENCE BETWEEN 5000 SERIES AND 6000 SERIES ALUMINUM ALLOY PANELS |
Type | Heating Limit Temperature | Proper Heating Temperature for Repairs |
AI-Mg Alloy (5000 series) | 300°C (572°F) | 250°C (482°F) |
AI-Mg-Si Alloy (6000 series) | 250°C (482°F) | 200°C (392°F) |
CHARACTERISTICS OF ALUMINUM ALLOY |
If the base metal of aluminum alloy is left untreated, it will naturally develop an oxide film that will protect against corrosion. As a result, an anti-rust agent does not need to be used even when aluminum alloy is exposed to heat during shrinking.
Aluminum alloy conducts heat very well so a wide area will become heated when heat is applied to one area.
Aluminium | Iron | |
Heat Conductance | 236 W/m*K | 84 W/m*K |
Aluminum alloy does not become magnetized.
PRECAUTIONS WHEN CONDUCTING REPAIRS |
If aluminum comes into contact with another type of metal (especially steel), galvanic corrosion will cause the base metal to corrode. If tools used to repair steel panels are not cleaned before they are used on aluminum alloy surfaces, the tools will leave behind steel particles and corrode the base metal.
Therefore make sure to completely clean off iron particles on the surface of tools if using them to repair steel parts before use, or prepare a separate set of tools (hammers, dollies, chisels, air sander, carbon electrode, etc.) for use on aluminum alloys only.
An oxide film forms on an aluminum alloy within a matter of minutes when the base metal is exposed to the air.
This oxide film has a negative effect on putty and paint adhesion, so it is important to immediately treat the base metal after sanding and degreasing.
Aluminum is brittle and easily develops work hardening and cracks. Heating aluminum when restoring a deformed portion improves workability and prevents work hardening and cracking so it is an effective method when repairing.
However, heating at the optimal heating temperature provides the very best results and any increase in temperature above this will result in a corresponding decrease in strength. (There is a marked decrease in strength if the optimal heating temperature is exceeded.)
CHOOSING THE REPAIR METHOD |
Damaged Condition | Judgment Criteria | Repair method | |
Repairable*1 | A dent on the flat outer panel surface |
| Repair by pulling. |
Deformation to the outer or inner panels. |
| Repair with a hammer and dolly by heating. | |
Not Repairable | Tears and hole openings | - | Replacement of the assembly. |
Damage with severe plastic deformation*2 |
THE WORK PROCEDURE OF EACH REPAIR METHOD (Repair by Pulling) |
![]() | Puller | ![]() | Industrial heater gun |
![]() | Washer welder (For use on standard steel panels) | ![]() | Carbon electrode |
![]() | Air tools | ![]() |
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CHECK OF THE DAMAGE
Inspect visually and brush your hand across the damaged surface to determine the condition of the damaged area and whether there is any stretching. Also, check for any cracking and paint peeling. In cases where no paint defects are found, conduct the work starting from (C).
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PAINT REMOVAL (NOT NECESSARY IN CASES WHERE THERE ARE NO PAINT DEFECTS)
Completely remove the paint at the points where bonding chips will be attached.
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DEGREASING WHERE THE BONDING CHIP WILL BE ATTACHED
After air blowing the surface, apply the degreaser cleaning solution that comes with the puller set to a cloth and degrease the area to be repaired.
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PREPARING THE PLATE HOOK
Heat the plate hook with an industrial heater gun and attach the bonding chip before it cools off.
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SETTING THE PLATE HOOK
Attach two-sided tape (or masking tape folded over on itself) on the back of the magnet for positioning and set the plate hook on the panel surface to secure it in place.
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ATTACHING THE PLATE HOOK
Heat the bonding chip with an industrial heater gun. Then use a handle of a hammer or the like to apply pressure on the plate hook and adhere it to the surface.
Next, air blow to cool down the panel surface and plate hook.
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SETTING THE PULLER
Fasten the magnet rubber plate attachment under the arm of the puller (with tape or the like) to prevent secondary damage.
Attach the eye nut to the plate hook and then attach the puller hook to the eye nut. Pull outward to about 1 to 2 mm (0.04 to 0.08 in.) past the height of the undamaged surface.
PULLING
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While keeping the puller pulled outward, lightly strike the convex surrounding area with a body line chisel or wood piece.
*1 | Pull |
*2 | Strike |
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REMOVING THE PLATE HOOK
After pulling, use an industrial heater gun to heat the bonding chip until it melts and then remove the plate hook.
Heat the leftover bonding chip and use a spatula to quickly remove it from the panel. Then apply the degreaser cleaning solution to degrease the panel surface.
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SHRINKING
Shrink areas that are elevated due to stretching with a carbon electrode to ensure tension.
After shrinking, remove the burn mark in the same way as when repairing regular steel panels.
THE WORK PROCEDURE OF EACH REPAIR METHOD (Repairing with a Hammer and Dolly by Heating) |
![]() | Gas burner | ![]() | Industrial heater gun |
![]() | Noncontact thermometer | ![]() | Temperature indication label |
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| - | - |
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CHECK OF THE DAMAGE
Inspect visually and brush your hand across the damaged surface to determine the condition of the damaged area and whether there is any stretching.
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PREPARATION FOR HEAT REPAIRS
*1 | Wet cloth |
*2 | Temperature indication label |
Cover the undamaged paint coating with a wet cloth so that it will not be burned by the flame of the burner while heating.
Put the temperature indication label at a position approximately 50 mm (1.97 in.) away from the heated area.
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HEAT REPAIRING
Evenly heat the bent portion.
Temperature | ||
Gas torch flame | 1300°C (2372°F) Maximum | |
Aluminum alloy panel heating limit temperature | 300°C (572°F) | Al-Mg Alloy (5000 series) |
250°C (482°F) | Al-Mg-Si Alloy (6000 series) | |
Aluminum alloy panel optimal heating temperature | 250°C (482°F) | Al-Mg Alloy (5000 series) |
200°C (392°F) | Al-Mg-Si Alloy (6000 series) | |
Aluminum melting point | About 650°C (1202°F) |
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REPAIRING BY HAMMERING
Rough Repairing
Aluminum quickly cools down after being heating so hammer the backside of panel with a plasticfaced or wooden hammer immediately after heating.
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Guidelines for Finishing Rough Repair
Even if there is unevenness in the surface, the repair is complete if the edge lines are restored.
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Repair with a Hammer and Dolly
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CHECK OF THE REPAIRED SURFACE
Check the following two conditions and repair by shrinking using a carbon electrode if either applies.
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REPAIRING DENTS ON THE INNER PANEL PORTION
If there are no high points, repair by putty shaping.
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If there are high points, place the nozzle of an industrial heater gun close to the high point, and heat it for 30 seconds.
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Repair the shape of the surface with a fine smoothening hammer before the heated portion cools off.
PROCEDURE AFTER PANEL REPAIR (PUTTY SHAPING, PAINTING, ETC.)
Conduct the procedure based on the work process below. (The basic work process is the same as for repairs on steel panels.)