BMW X5: Bonding Aluminum Parts

IMPORTANT: Conform with safety precautions!

Overview of topics:

1. Equipment
2. Best before date of consumables
3. Grinding and cleaning
4. Flame-coating
5. Primer coat
6. Gluing coat
7. Hardening times
8. Disposing of adhesive

1.0 Equipment

• Emery paper
• Cleaning agent: Isopropyl, acetone or spirit
• Brush, cotton wadding or similar
• Adhesive cartridge (sourcing reference via BMW Parts Service picture board 83-0371 Aluminum and steel/bonding and welding)
• Primer
• Flame coating set
• Spatula for applying adhesive

2.0 Best before date of consumables:

• The adhesive cartridge, primer and special gas cartridge are all marked with a date.
• Do not use the adhesive, primer and special gas cartridge after this date.

3.0 Grinding and cleaning:

• For better adhesion, remove oxide film and paint from the adhesive areas with a stainless steel wire brush or special emery paper.
• Clean adhesive areas with isopropyl, acetone or spirit.
• Allow cleaned surfaces to dry for approx. 5 minutes.

  Adhesive areas must be completely dry.

• The ridges on the repair parts (clamping pieces) approx. 0.5 mm high serve to orientate the minimum adhesive thickness. The ridges must not be ground off!

4.0 Flame-coating:

• Go over the adhesive areas slowly with the flame.
• Avoid flaming with the blue part of the flame.
• Condensation water appears on the area that is still uncoated. The condensation water in the line of the flame must evaporate completely.
• Directly after flaming, coat the still hot adhesive areas (approx. 50ºC) with primer.

5.0 Primer application:

• Apply the primer with a brush, cotton wadding or similar.
• Allow the coated surfaces to dry for approx. 5 minutes.

6.0 Adhesive application:

• Processing temperature of adhesive cartridge 15ºC - 25ºC.
• Do not use any compressed-air-operated cartridge guns.
• Insert adhesive cartridge in cartridge gun, remove cap and allow both adhesive components to emerge. Strip adhesive components uniformly and attach mixing tube.
• Allow approx. 10 cm of mixed adhesive to emerge and then apply the mixed adhesive first on one side of the adhesive area.
• After applying the adhesive, check whether an adhesive component has emerged at the back of the cartridge. If yes, break off the bonding procedure. Clean new component. Use new adhesive cartridge. Contact national hotline.
• Use a spatula to spread the adhesive over the adhesive area. Thickness of layer approx. 2 mm (dependent on adhesive gap).
• Potlife of mixed adhesive approx. 2 hours. A change of mixer is only necessary if over a period of 1 hour no material has flowed through the mixer.
• Join components and secure in position.
• Remove excessive glue with paper or cloths.

6.1 Bonding in conjunction with repair parts (clamping pieces):

• Bonding with clamping pieces is necessary in the event of structure damage. E.g. partial replacement engine carrier.
• Clamping pieces are special shaped parts for connecting new extruded section parts with the extruded section on the body.
• Clamping pieces expand when a special screw is inserted. This establishes a positive connection with the relevant extruded section.
• Ensure there is a sufficient gap between the adhesive and the threads for the expander screws (approx. 10 - 15 mm).
• Spread adhesive over the clamping piece with a spatula up to the height of the ridges.

6.2 Bonding in conjunction with rivets:

• Bonding in conjunction with rivets is necessary in the event of structure damage.
• Ensure there is a sufficient gap between the adhesive and the bores for the blind rivets (approx. 10 mm). Risk of damage to replaceable head of riveting tongs by emerging adhesive.
• The standard punch rivets are always replaced by blind rivets in conjunction with bonding.
• The required strength of the connection is only achieved through a combination of bonding and riveting.

7.0 Hardening times:

• Vehicle is permitted to be lifted with the lifting platform from the straightening bench directly after bonding/riveting. Only raise the vehicle at the jacking points provided for this purpose.

  Do not subject bonded parts to load for 12 hours at a minimum temperature of 15ºC (room temperature).

• Vehicle strength for driving applications is achieved after: An additional 36 hours at a minimum temperature of 15ºC (room temperature).
• Do not use radiant heaters for hardening. Risk of adhesive being destroyed at temperatures of > or = 120ºC.
• Remove contamination caused by residual adhesive immediately.

Hardened adhesive can only be removed by machine.

8.0 Disposing of adhesive:

• Hardened adhesive is disposed of as normal waste.
• Empty adhesive cartridges are disposed of as normal waste.
• Non-hardened adhesives and mixtures of adhesive and solvent and the like must be disposed of as hazardous waste.

These regulations apply to the Federal Republic of Germany.

For other countries, comply with the (possibly differing) nationally applicable regulations.

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