Mag welding
 

Is anyone doing mag welding nowadays? I need a few fan shrouds repaired. So far I have had no luck with the usual suspects.
http://forums.pelicanparts.com/uploa...1545147826.jpg

Try mb911 here on the forum. He is an experienced fabricator, and I believe he can repair mag fan shrouds.

Scott

Thanks, just sent him a message!

won't magnesium burn (ignite) if it gets hot enough...like when welded?

Chris

Ben/MB911 has done mag fans, shrouds, 3.2 manifolds and 915 trans cases for me. Saved some important parts for way less than replacement cost. He is a pro. He also does stainless steel and aluminum.

Magnesium burning
 

I once made a bunch of magnesium shavings from a junk piece, put them in a pan, and added a flame. With some effort they did burn, though not quickly or sort of explosively. The bulk of our mag parts (and maybe the alloy?)seems to preclude them burning in the kinds of fires we tend to see in and around our 911s.

img]http://forums.pelicanparts.com/uploads26/mag_shavings1546478351.JPG[/img]
http://forums.pelicanparts.com/uploa...1546478351.JPG
http://forums.pelicanparts.com/uploa...1546478351.JPG
http://forums.pelicanparts.com/uploa...1546478351.JPG

I once had the hole in a case half caused by a wayward rod welded up and remachined - worked fine. The fan housing looks like it might be trickier (nothing to machine when done?), but at least it isn't a rotating part, and there won't be a flash fire.

Beyond the DIY abilities of a guy like me with only a small MIG, though.[

Mag for the most part is very stable and takes a lot to ignite unless in powder form. If it ignites you want to smother it with sand or a class D fire extinguisher. You never want to use water and don't disturb it once covered otherwise it will reignite once oxygen is reintroduced. Do remember they use raw mag powder in fireworks and in powder form will ignite and spread very quickly.

The trick to welding mag is preheating it to around 500+ degrees prior to welding. You will want to grind away any corroded metal and V grove it prior to welding.

I used to do this all the time but haven't since I retired and no longer have the equipment.

30 plus years of tig and carpel tunnel issues to show for it. Cobalt, what filler rod to use? Will parent material work in its place?

I had a similar need for a 914 transmission case. I called the local junior college and spoke with the welding teacher there. He gave me two recommendations for local guys. One answered his phone and did exactly what I needed for $80.

I know for sure he repairs fans for a couple of the well known shops, he was doing a big run on them not long ago.
He also makes beautiful 914/6 SS header/heat exchangers and a bunch of other 914 parts.

I don't know the specific alloy they used and in most cases you could get away with AZ101 filler rod but since most of my parts were made from AZ91 or AZ92 I would cut strips of material from ingot as filler.

Although it can be welded a fan housing is one thing a case is another. Welding isn't as much an issue as strength. You do kill the temper when welding so although the material is solid it should be done prior to heat treatment. Usually when making cast parts that will have subsequent welding processes they are supplied in a T4 or T5 condition and then aged to T6 after the welding is done or all welding is done prior to any heat treatment processing.

The issue is how long will the weld last if the parts aren't reprocessed to T6 condition which isn't easy to do when tight tolerances are involved. At least mag is best when air cooled vs aluminum which gets a liquid quench.

Our in house welder has repaired many a 3.6 case where they commonly crack. Nothing to special, just aluminum welding done by a pro. You can talk all day about how to or how not to or take it to a pro and get it done.

Aluminum is very different than Magnesium

Yes, I agree. Our guy doesn't do Mag, that's why I send that stuff to Ben. It just takes the right guy using the right process. Mag welding has been done for ages. Porsche even welded up a mag 917 chassis. I don't know if it was ever raced.

I did it for nearly 30 years myself. You couldn't tell it was done even after radiographic inspection however it doesn't change the fact that both aluminum and magnesium will loose their temper when welded. Tensile strength will be seriously diminished.

Kickass repair by MB911. Thanks to all you guys for your help.http://forums.pelicanparts.com/uploa...1548202395.jpg

A few magnesium framed 917s raced. I have it in my memory that the accident in a 917/10 that cut short Mark Donohue's 1972 season was a mag-framed car, but I'm not sure about that part.

Not the prettiest weld I have ever seen but won't be seen and will do the job.

Looks pretty pretty from this angle.http://forums.pelicanparts.com/uploa...1548253187.jpg

Agreed and in this case that is all that counts.