Procedures

51 16 ...Cementing Of Mirror Base

Material Requirements:
Repair set for cementing of mirror base (Sourcing Reference: BMW Parts Service)
Primer XW 775 (Sourcing Reference: BMW Parts Service)

1. Preparations
1.1 Cement at room temperature and make sure that, in cold weather, the window glass and base are brought to room temperature in the workshop long enough to prevent moisture forming on the surface.
1.2 Mark location of the mirror mount on the outside of the windshield.
Scratch off cement residue on glass and base with a sharp tool.
1.3 Clean cement area on window and base with clean non-fluffing cloth and alcohol/cetone and allow to dry.
Never use paint thinners.

2. Primer Coat
Apply colorless, diluted primer to surface of windshield intended for cementing with help of cotton buds (Q-Tips or similar).
Specified ventilation time at least 10 minutes, maximum 1 hour

3. Cement Coat
3.1 Mixing Cement
Trim off sealing tips on containers of cement and hardener using a knife.
Make sure that both openings are equal in size, as otherwise there would be mistakes in mixing.
The sealing cap for subsequent plugging of the double injector is located between both pistons of the injector. Break off sealing cap.
The required amount of cement and hardener is removed by applying light pressure on the pistons.
The mixing ratio for cement and hardener is 1 : 1 (weight and volume). It is important that the same volumes of cement and hardener are removed (increase size of openings if necessary).
Both components react chemically with each other. Thorough, intensive and homogenous mixing is a requirement for this reaction and for the quality of cementing.
Consequently both components must be mixed in such a way that there is a uniform, ream-free color mixture.
3.2 Application
At 20 ... 25 °C the mix can be processed after approx. 5 ... 10 minutes (pot time).
Apply thin (approx. 0.5 mm), uniform coat of cement on base with spatula and press base onto glass in such a way that cement obtains good contact with windshield across the entire surface area.

NOTE: The temperature for the hardening process should not be lower than +18 °C.

3.3 Fixing Bonded Parts
Epoxide resin cement does not have an initial strength property. It is therefore necessary to fix all bonded parts (cement tape or similar). The joining and fixing of bonded parts must be accomplished within the potlife). Check that the arresting button is located correctly on the mirror base to ensure that the mirror, when it is attached, is seated straight.
(Long side of mirror base hexagon parallel to upper edge of window).
3.4 Hardening of cement
Hardening speed depends on the ambient temperature.
For this reason, the mirror base must be secured with adhesive tape or similar for at least 3 ... 4 hours.
After 12 hours have elapsed, clip mirror into place as soon as possible.

4. Working Hygiene

CAUTION: Cement is dangerous for health when vapours are inhaled or through contact with the skin.

As is the case for all epoxide resins, sensitive persons might be confronted with an alergy through contact with the skin.
If the product gets on the skin, wash off with soap and water immediately.
If it gets in an eye, rinse the eye thoroughly in water and consult doctor.
Make sure that the room is well ventilated and gloves are worn for the application of cement.