Question on MSG-Brazing

[TonyWilk]

Hi,

Having read some of the posts in here about welding up cars I remembered an article I saw about brazing...

I thought a lot of cars now are brazed 'cos it can be done on plated steel without destroying the plating.

Is this an option for the hobby restorer ?

Yours,
Tony Wilk

 

[matt1978]

Mig Brazing or MSG Brazing as its also called is used quite extensively throughout the Automotive repair industry. It was used as early as the 50's in car production but it got phased out. Its really became popular lately as you said, because a lot of car manufacturers are using high strength coated steels simerla to "Boron" steel.

These high strength steels cannot be sucessfully welded using the conventional mig process, as this process puts too much heat into the parent material, which in turn, changes the mechanical strength and corrosion properties of the material. So they use mig brazing, which is as the name suggests, a Braze (Utectic bond) as opposed to a weld. The filler wire, (usually Copper Silicon based "CuSi 3" or Copper Aluminium "CuAl 8") are the most common, melts at a lower temperture than the parent material so the parent material is not melted with the weld pool.

The benefits of this are a lower heat input, which means that the properties of the parent material are retained. This can also lead to less distortion. This process can also be used on conventional "steel", and because the pool is very liquid, its good for filling gaps, especially on things like "puddle/plug" welds.

The finished Braze, is also very easy to work with as its quite soft compared to conventional weld metal. Its easily linished off when preparing a joint for filling.

You can use 100% Ar or 95C Co2 5% Ar mix. You would be better with a Teflon liner and the same groove rollers as you would use for Aluminium.

The filler wire is very expensive compared to normal Sg2 though, probably as much as 5 times the cost!

 

[dutchman]

Excellent piece of info there Matt!

How about TIG brazing? Is that comparable? Can that be used on most/all metals?

 

[matt1978]

Although it is possible to Tig Braze, its not very common. There is however Plasma Brazing, which is reasonably popular, can be used on most materials and can also be used to join Aluminium. At my previous employer "Fronius", we had to go head to head with a company called Arc Kinetics, for a large order in Jaguar, for welding one of the joints on the "New XJ". It is a Aluminium car, and the joint was 0.9mm sheet, joggle joint.

In the end we got the business, but the Arc Kinetics Plasma brazing system was very very good, the decision to go with the mig/double pulse process was only because the Plasma system was very expensive in comparison and required a lot of torch access.

 

[matt1978]

Hi Dutchman, I am going to be helping out my colleage in Holland in March, at the Welding show in Utrecht. Why don't you pop along and you can try some of our machines out, we'll probably have mig brazing unit set up too.

 

[TonyWilk]

*snip*
Its really became popular lately as you said, because a lot of car manufacturers are using high strength coated steels simerla to "Boron" steel.

These high strength steels cannot be sucessfully welded using the conventional mig process... *snip*

Thanks for the info Matt... does this mean that on newer cars you would have to braze repair to avoid ending up with a weaker structure ?

Yours,
Tony Wilk

 

[matt1978]

If the car was made from a high strength steel, yes you would.

Its only been cars in the last 6 years or so though.

 

[TonyWilk]

Thanks again Matt, that's very interesting - and maybe slightly worrying...

...makes cars less repairable (properly) without more advanced kit/skills.

Mind you, they're getting more 'throw-away' just like everything else - my line was in electronics and, at one time, I could fix just about anything.
Nowadays, I can't even see some of the components

Yours,
Tony Wilk

 

[matt1978]

To be honest I think a lot of this was born from the "where theres blame, theres a claim" culture.

It was General Motors and the Vectra C, which really kicked it all off. They got 5 welding machine manufacturers in to repair a Vectra C in Germany, and then the settings that were decided upon were pre-stored in the machines prior to them being sold to the bodyshops.

If they wanted to keep there status as a Cat "A" repair shop they had to buy one of the 5 welding machines and a new spot welder. They were told how much the units were going to cost, basically take it or leave it.

The idea was, that if a Vectra C came in for a wing or sill repair etc, the operator was issued with a step by step drawing telling him how to repair the car and what welding program to select from the machine. It all kind of snowballed from there.

My claim to fame, (in quite a sad way) was that I developed all of the programmes for Fronius, for repairing the "New XJ", which was Jaguars first production Aluminium car. Only the Fronius machine was approved by Jaguar, so every Cat "A" body shop globally had to have a Fronius welder, with my programmes pre-installed. I also got the Speedglas Adflo and Nederman extraction approved. Nice little earner that was while it was going on, because, from the UK, we supplied all bodyshops worldwide, except north america!

 

[JW240]

Hi Dutchman, I am going to be helping out my colleage in Holland in March, at the Welding show in Utrecht. Why don't you pop along and you can try some of our machines out, we'll probably have mig brazing unit set up too.

Technishow? i will be there as well if everything goes to plan. i'd love to have a closer look at the Lorch range, I almost bought a 180T ac/dc(price was the only obstacle though )

 

[matt1978]

Yes mate,

Here is the stand number Lorch Lastechniek B.V. 09.D065

Maybe see you there.

 

[JW240]

I looked at the Mig brazing as well, seems like a very nice technique.
What is up with the tig brazing Dutchman mentioned? im not familiar with that, seems interesting now that i have a tig machine (with too many functions )

Yes mate,

Here is the stand number Lorch Lastechniek B.V. 09.D065

Maybe see you there.

that would be nice indeed!

Lorch has super nice equipment, i saw the V series (and other ones) at my welding supplier (In Aachen, Germany) last week...

 

[matt1978]

Yeah V series and S Series are the best ones too see.

Have a good week, see you later.

 

[JW240]

Yeah V series and S Series are the best ones too see.

Have a good week, see you later.

same to you!

 

[dutchman]

Sounds tempting Matt, but I am afraid I can’t make it though.
A pity because I really would like to see the HT-180 AC/DC and maybe try it on aluminium.
Would not oppose to meeting the men behind the screen either and maybe slam a couple of Heinekens.
Utrecht would have been a good place for that! Some other time perhaps.

 

[matt1978]

Technishow? i will be there as well if everything goes to plan. i'd love to have a closer look at the Lorch range, I almost bought a 180T ac/dc(price was the only obstacle though )

Did you make it JW240?

 

[dutchman]

Maybe he had a flat klomp
Or possibly got too distracted by those foxy demo-women.

Just joking around JW. You were probably doing what many of us should have done at your age, getting drunk... ehrmm I mean studying for your exams

Matt, could you upload a larger picture of that stand??

 

[matt1978]

Hi Klompie ;-)

We were lucky because they have used to photos from the stand on the Technishow website....

http://www.technishow.nl/sites/bezoekers_technishow_nl_2/nl/page.asp?module=pages&type=item&id=18760

 

[matt1978]

More pics.........

 

[matt1978]

The welding demo booths were pretty cool, they had a automatic sliding dark glass bit for viewing and a Plasma tv hooked up to a auto darkening camera, so you could see the welding on the screen