blown 87

There is a reason it is outlawed in some countries, it puts to much heat into the metal over to long a period of time.

I sent Joe Norman a note to come check this thread out, he is a old time MASTER welder, if I says I am wrong, then I will make a post saying so, will you?

To tell you the truth, if he can get a really good panel, if it were mine I would be tempted to use adhesives on it.
I welded the aluminum fronts markers and holes for the rub stips, and the steel rears, but used adhesive custom patches on my doors as a trial, and so far so good.

The glue takes all the heat out of it.

Podguy

Gee Jerry,

You stuck your nose in it now. I would refer your new friend to the Tinman

http://www.tinmantech.com/

Kent White has some interesting old videos of rails being repaired with gas welding. He also has some videos of production gas welding on aluminum. Although I have done a lot of gas welding I do have to admit gas welding aluminum is an art I can't seem to master.

Being in the body shop business years ago we gas welded many many panels and never had a single problem. Personally on the 928 since Porsche decided to go that route themselves I would chose brass brazing. The quarter panels and parts of the sun roof are all done with brass brazing. Obviously brass brazing was fast enough for a production line of 928s.

Sure MIG is good technology but it is also easy to burn through and warp thin panels with a MIG. The advantage of MIG is speed and maybe having a non oxidizing weld.

I suppose next we will be treated to a lecture about how one should never use gas to shrink and staighten steel either.

blown 87

That is what I use gas is for, to shrink metal, but I have to admit, never was very good at that.
Brazing is a very different deal, you do not have to get the metal near as hot.

Ad0911

Just what did Porsche think about this type of repair? The 911 WSM of October 1971 says to use an oxyacethylene torch. It is an art in itself to do it like that. later on, Porsche approved the MIG welder.

polecat702

After viewing the pictures of the rust damage, I've concluded that the easy way to repair this car would be to cut out and resection a repair piece from a donor car. As Porsche uses 14 gauge galvanized sheet metal, I would use my TECNA 3664+ CEBORA MIG Welder. All welding parameters are factory download, without any operator input. This unit will weld Boron Steel-Dual Phase Steel-Galvanized Steel, and Aluminun, without panel warpage or distoration, with factory approved pre-weld tacking.

At $28,500.00 plus shipping from Italy, I doubt any other RL member has a mig welder like this. This unit was built for panel repair on Ferrari, and has a direct link to the factory, via the web. I do a lot of aluminum fabrication, and this is the only mig welder that will weld aluminun sheet metal, in a continuous run, fast and clean with zero distoration, and zero base metal degradation, in the heat affected zone.

The cheapest and fastest method is brazing in a repair panel from a donor car. Gas welding in IMHO would put to much heat in a small area, and cause rippling, from expansion of the base metal. Lots of skill, and patience is the key if using this method. Not for a beginner.

Mig welding using the stitch teknique, and top and bottom panel tacking, with low heat to control warpage. Lots of sanding involved.

Or a spray arc welder, unit is rare, expensive, and there is only one here in Vegas.

Landseer

^^^ Wow!

blown 87

And that is the final word for me, Joe knows welding.

polecat702

Thanks Greg, I do know how little I know! Welding technology is changing by the day.

Last year at SEMA, I saw and used a Metal Spray Arc welder! This machine sprays molten metal just like spray painting. This machine will restore to original gauge, aluminun, or steel panels, that are paper thin, and fill in missing materal. In the not to distant future, we'll be able to restore full body panels, with just the outside seams, or a picture of the panel downloaded into the welding machine.

robot808

Everything about this post kicks ***.

blown 87

That is cool stuff Joe, is that anything like plasma spray?

polecat702

Don't know, could be just a MFG's trade name. Machine generates a ton of heat, but the results were spectacular! It's on my wish list!

blown 87

They use them on turbine buckets on jet engines that have pits or wear on them, neat stuff, looks like a flame, but sprays metal.

Podguy

Add 3D printing with the metal spraying and we will be able to just print new panel parts from CAD drawings. Talk about automotation replacing body men.

Podguy

Wow - in a previous post you wrote that you had a lot of experience at metal work. Now you write that you are not very good at metal shrinking. I thought the entire job of metal working was about metal shrinking and working. Without heat I am unsure how one would work metal without a ton of bondo.

Am I missing something here in my education and esperience?

blown 87

I did not say I could not do it, I am just not very good at shrinking a lot of metal.
Like when a panel has a long deep gouge in it that did not go through the metal.
Most of what I did was making and replacing parts that could not be bought or found.

PS, you do know you can shrink metal with out heat.