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MIG brazing (non-EU)

MIG brazing (non-EU)

MIG brazing has been introduced as a production process and this entails revised repair methods for garages. Certain welded joints in the car have been replaced with a new type of joint with bronze rod filler metal, so-called MIG brazing. A MIG brazed joint can be recognised by its golden colour.

Warning

Repairs to MIG brazing using conventional welding methods and normal filler material are forbidden. Cracks can arise which can impair performance in a collision.


There is a new procedure for the repair of panel damage where there is MIG brazing. Before Saab workshops have procured new MIG brazing equipment, damaged cars with MIG brazing can be repaired with existing welding equipment but instead using bronze rod and argon gas.

In all cases 100% pure argon gas must be used and the welding rod must be 1 mm.

The appearance of a MIG brazing joint differs compared with a conventional weld joint. In order to obtain good results for welding when using a standard machine the rod supply must be adapted and the power reduced. However, when welding with low energy the arc is occasionally broken and it involves a stronger spattering and more spray. A good MIG brazing joint must be evenly rounded.

MIG brazing emits a significant amount of zinc gas in the molten material and brass is formed, with few or no air holes as a result. As MIG brazing is a soldering process where the plates do not need to be melted together, there is also less risk of burning holes. In the cases where grinding is required the welds are considerably easier to grind.

Ensure that the independent workshops which are engaged have access to this information.


Parts required

• 16-93 180 983 Bronze rod 1mm

• Pure argon gas

• Hose package, if required


Procedure

When converting existing welding equipment the following procedures must be carried out:


1. Clean the feeding mechanism and the feed rollers.

2. Ensure that the hose package and welding torch tip are in good condition. Replace if necessary.

3. The pressure on the feed rollers should be low to prevent the rod from being broken.

4. The hose package should be held as straight as possible so that it is easy to feed the rod. The welding torch tip must be held at a right angle in relation to the weld joint.

5. Test the welding equipment first on several test plates to obtain the correct setting for the weld. Do not use too much heat. Check on the rear side of the plate that burn-through has not occurred. A good MIG brazing joint must be evenly rounded.

Lap joint :


Butt joint:


6. Test the strength of the joint by pulling the panels apart using adjustable pliers or pipe wrench with the panels secured in a vice. The result of a good joint is that the surrounding panel gives way and not the brazing itself. Adjust the setting of the weld if necessary.