BMW X3 Service & Repair Manual: Soldering steel components

IMPORTANT: Comply with the following topics from "Body, General": Safety regulations .

Handling electrical system, electronics, airbags and restraint systems .

1. General information

• For repair cases the following procedure will implemented:
  • Autogenous brazing solder
• The MIG soldering procedure is not used in repairs for strength reasons. MIG soldered/brazed seams used in standard production are replaced during repairs by MAG weld seams.
• Brazed areas from vehicle production are bonded following the same procedure.

2. Work materials

• Tube pack and torch (autogenous torch)
• Brazing solder
• Gas bottles (oxygen and acetylene)
• Welding goggles

3. Preparation

• Remove the paint and zinc layer in an area of approx. 30 mm around the seam to be soldered.

4. Implementation

• Execute brazed seam without overheating the solder and with low heat dissipation. If necessary, use heat protecting paste.

5. Subsequent treatment of brazed connections:

• Remove burnt residual zinc completely. Align and grind visible connection faces.
• Remove burnt paint with a stainless steel wire brush.

6. Notes on melting/tinning: Only applicable within the European Union! European used-vehicle regulations prohibit the use of tin containing lead in motor vehicles introduced after 01.07.2003! Even out unevenness smaller than 2 mm with filler according to painting handbook If an exceptional unevenness is larger than 2 mm, use METAL FILLER.

Only perform in visible areas of the outer skin and on the carrier support.

All areas which have covers on the vehicle are not to be processed.