Bronze MIG wire for cills?

[JOEPRO]

I ordered a spool of this to try:



Is this OK for jacking point / cill repairs? I am thinking of my 1989 Merc Cosworth if this is worth using for better corrosion resistance.

Does this wire also require pure Argon gas?

 

[Pigeon_Droppings2]

This is mig brazing wire...I use it for repairing frilly door bottoms and the like. Brazing is lower temperature but is NOT the same as welding with steel wire.

I would say it's not suitable for general car use (unless specified by the manufacturer).

It is handy stuff to have....I've used it a lot for other projects like making up special stainless water fittings etc.

 

[DaveB]

I thought repair to steel vehicle panels needed to be welded unless you can demonstrate that the original was brazed ?
Sure an mot expert will be along soon.

Previous thread in similar subject https://www.mig-welding.co.uk/forum/threads/silicone-bronze-mig-welding.139286/

 

[BrokenBiker]

I wouldn't braze structural parts personally.

 

[Seadog]

Like motorcycle frames?

 

[BrokenBiker]

Like motorcycle frames?

Which are usually made with the strength in the joint, not the braze

 

[Jelly_Sheffield]

I ordered a spool of this to try:

View attachment 535116

Is this OK for jacking point / cill repairs? I am thinking of my 1989 Merc Cosworth if this is worth using for better corrosion resistance.

Does this wire also require pure Argon gas?

The MOT manual has an absolute prohibition on brazed repairs unless they are replicating how the OEM built the vehicle.

For structural repairs like cills or jacking points, you should be welding in new metal back to the last solid point on the body, nothing else is really adequate.

 

[Turbo]

On the 3 door 205 the lower panel behind the b post is brazed on.

 

[Morris]

Like motorcycle frames?

And Lotus 7 chassis in the early days.
It has it's advantages, no HAZ and low distortion.
No matter, the MOT manual is absolute on this.

 

[bricol]

That used to be a delight with old cars that had had a few MOT bodges - hitting unsuspected braze with the MIG.

 

[Pigeon_Droppings2]

Japanese cars from the 90s usually have brazed panel joins...my nissan has them on the rear quarter and the roof. I'm guessing it was done that way to avoid heat distortion.

Quite nice to see them as they're always lovely and neat too.

 

[premmington]

It is an MOT failure - but once undersealed nobody would ever know.

MIG brazing is fast - but the wire is very expensive in 15kg sized rolls - so is pure Argon.

It is the ultimate low temp glue gun...

No it is not steel melted together with an A18 filler - a full fused joint - it is adhesion and surface tension.

But it does stick and hold - if you do a test piece and try to tear it apart - panel thinkness metal will tear before a MIG braze...

 

[jo1010]

/\ that's true for thin panels which is a legitimate use, but the thread started by talking about sills and jacking points - which limits the use of braze somewhat...

 

[premmington]

/\ that's true for thin panels which is a legitimate use, but the thread started by talking about sills and jacking points - which limits the use of braze somewhat...

I agree 100% - it not up to sills of jacking points or anything 300mm near a seatbelt or suspension mount

 

[Bullet2012]

seems its the new old way

https://www.bodyshopbusiness.com/mig-brazing-a-popular-choice-by-automakers/

 

[jo1010]

seems its the new old way

https://www.bodyshopbusiness.com/mig-brazing-a-popular-choice-by-automakers/

Yes. Specifically for bonding of high strength steels where the fusion of a welding process would cause molecular damage to the heat sensitive high strength steel. In those cases OEM design has (presumably ) assessed the forces acting in those areas and concluded that the bonding produced by braze reaches acceptable limits. So any aftermarket repair should use a process similar to the OEM design. I take that to mean fusion welding for mild steels and more controlled heat processes for higher strength steels...