The Much Maligned Mag Melding Mission!

[SkippyKtm]

Let me start out by saying that I am no expert when it comes to Tig welding, in fact, I'm a rank amateur, a baboon probably could do better, but I figured I'd share my experience anyway.

I bought some AZ92T60 magnesium tig filler rod off eBay. The stuff is pricey, but worth it. I had previously made a failed attempt using filler rod for aluminum and the welded joint cracked as it cooled, fortunately that wasn't a problem this time.:rolleyes2:
This photo is my test run (try not to laugh too hard!):
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I know it looks like I was drunk when I did it, but at least its stronger than JB weld (maybe!). So with my confidence up, I decided to tackle the real task: a 372 case half I got from Leeha (thanks, Lee!)

D'oh! I forgot to get a "before" picture of the case half (the AV spring mount hole was very badly elongated, it was about a 3/8" long oval hole).

So here's the first run at welding:
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Yep, I nearly burnt(!) the house down, that white residue you see is from the mag burning! Fortunately I was doing the work in the carport for just this reason. I've never seen mag light on fire, now I can say that I have.:msp_scared: Anyway I was very lucky as the mag was very thick in that spot and it was just the slag that was on fire. I thought I was going to have to hurl the case out into the driveway and let it burn, but it went out when I smothered it with my glove (I know that was very stupid, but it worked!).
My tig welder intermittently will go into "DC" mode, and I think that is what caused the Mag to light up like it did. I reset the welder, cleaned up the case again, and this is my second attempt:
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Not too bad, I suppose.:msp_rolleyes:

 

[HILLBILLYREDNEC]

Repair

Nice looking job. Gives new meaning to trial by fire

 

[SkippyKtm]

So here's my rig:
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Its a Lincoln V205T inverter Tig welder. -It works alright except when it decides to go into DC mode for no apparent reason. I had it in the repair shop under warranty, but it worked "just fine" they said:bang:
Here's another pic of the rig:
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Here's a photo of the weld on the back side:
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[sunfish]

Not bad at all, man!!!

 

[Modifiedmark]

Glad to see this thread as I just picked up some pure tungsten for my setup the other day.

I'm also a rank amature with a tig torch, but I figure I mastered most of the other types of welding, so I should be able to do this as well.

Too many old parts need fixing not to try.

Looks like you got a good start on figureing it out.

I was told to be carefull when doing Mag to not let it cool off too fast or it can crack, so I'll keep this in mind.

 

[SkippyKtm]

I flattened the welds out on the front and back:
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<a href="http://photobucket.com" target="_blank"><img src="http://i518.photobucket.com/albums/u349/skippyktm/PICT6146.jpg" border="0" alt="Photobucket"></a>

Milled out the recess with a course carbide burr:
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Then flattened the bottom of the hole with a forstner bit, I know the bit is made for wood, but it did a nice job, and the mag didn't dull it one bit!
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Here's the finished result:
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:msp_w00t:

 

[Stumpys Customs]

What kind of shielding gas are ya usein??

Good job by the way :msp_thumbsup:

 

[smilin possum]

You did a good job on that part. Now you are going to be everybodies best friend with something broke that needs to be fixed. It don't always pay to let folks know what you can do. Me I pretend with great success to be dumb as a box of rocks.

Find all the scrap you can and practice all you can. If this was your first attemp you gonna get better the more you do. One hint to build up use the lowest amp setting that will give you good flow and movement it all comes with practice.
Joe

 

[Stumpys Customs]

You did a good job on that part. Now you are going to be everybodies best friend with something broke that needs to be fixed. It don't always pay to let folks know what you can do. Me I pretend with great success to be dumb as a box of rocks.

Find all the scrap you can and practice all you can. If this was your first attemp you gonna get better the more you do. One hint to build up use the lowest amp setting that will give you good flow and movement it all comes with practice.
Joe

I like the way ya think. I'd rather chalk up any of my success to dumb luck than being good.

 

[SkippyKtm]

What kind of shielding gas are ya usein??

Good job by the way :msp_thumbsup:

I'm using Argon, I've heard that the argon gas will help prevent the Mag from igniting. Don't know for sure if that's true or not.
I wonder if Bob Wright is around, he was very helpful in guiding me on finding the right magnesium filler to use. He may know more about the argon gas, I hear the only other gas used with tig welding is helium/argon mix with aluminum, it helps with penetration when you're using a smaller machine.
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[SawGarage]

Nice...



Good work Chris...


GLAD the case didn't ignite! mag is next to impossible to extinguish... :msp_ohmy: as most well know....

I would think the DC probably caused an issue! YIKES!


like MOST dealerships...they PROBABLY didn't do much more than a bead, or two... IF not just turning the machine on :msp_rolleyes:


Joe, some people like to help friends too, ya know BUT I 100% know where your coming from... ya don't need all the 'beggars' running around

J

 

[SkippyKtm]

Just wanted to add that I found the link for the magnesium filler rod, in case anybody wants to try this. The seller's id is rocketbracket and here's the link:
http://cgi.ebay.com/new-AZ92T60-magnesium-tig-welding-rod-1-8-size-/230530437730

 

[leeha]

Looks good Chris, Welding magnesium can be tricky.
The right rod is a must.



Lee

 

[srcarr52]

A few things that will make you look like an expert.

When it comes to tig welding 30 seconds of surface preparation will save you minutes welding. You're welds will come out much nicer and the weld pool will be easier to see if you do a little more prep work. Aluminum and magnesium form a oxidized coating on them quickly (days on bare metal) that melts at a much higher temperature then the base metal. This will cause you to over heat the material and have a drop out or a fire with magnesium just because you won't see the molten pool under the oxidation coating. So the surface to be welded should always be sanded, bead blasted or hit with a wire brush before welding.

Don't use a wire brush or sanding disk that had been previously used on steel (the small rusty bits will get embedded in the surface of the aluminum/magnesium and cause you hell when welding).

You shouldn't ever be burning through paint with a tig welder. It causes major contamination of the weld. It may be the main contribution to your mag fire. The shield gas will keep it from burning when the torch is there, but if the paint ignites after you remove your torch due to the heat, it could be enough to ignite the mag.

That black residue could be from you dipping your tungsten in the weld pool or from oil coming out of the porous die cast magnesium. It's almost impossible to get all the oil out but get as much as you can because once again it will cause a coating on your weld pool that is hard to get filler rod through.

Last bit, magnesium burns hot... way hot. So hot that it can break the bond of water and turn it back to pure hydrogen and oxygen. So water on a mag fire is like trying to put out a normal fire with gasoline. You best bet is to smother it in sand and the finer the sand the better. Best to have a large bucket ready to dump. Most of the time I have a steel pan with a good base of old glass beads from the blaster and another bucket to dump on it once I knock the burning piece off the bench into the pan.

 

[Bob Wright]

I am here. I have only used Argon. I have 2 tigs but mine are DC only Yes get everything as clean as you can get and wipe the rods and parts with Acetone before welding. The stuff Oxides in a few minutes...Bob

 

[Oxford]

I am a pipefitter by trade and work with some guys who are beyond good as welders. One of them in particular is absolutely unbelievable. He is very popular with the motorcycle crowd because he has retrofitted a sandblast cabinet so that he can place a motorcycle wheel or other similarly expensive part in it, place the whole cabinet in an inert gas environment, and weld without danger of burning up the part. Some of the things he's fixed look better than they did before they broke.

And he built this because the first mag wheel he worked on caught fire and burnt to cinders in his shop driveway because he couldn't get it out.

 

[PLMCRZY]

Doesnt look to bad. Key thing is getting it really clean. Cant use a steel brush it needs to be Brass to make it clean. The only thing i have tig'd alot of is Stainless steel the rest i havent messed with.

 

[SkippyKtm]

I want to get a blast cabinet so I can bead blast the parts, ande not lose the blast media. Right now I'm using carb clean (not brake clean!) a stainless steel brush, and a little hand held sand blaster.

 

[Hddnis]

To the OP, I only mean this in a helpful way, but your parts are nowhere near clean enough to be trying to weld them. Cleaning the weld area is a start, but having the whole part clean is almost a must with mag welding projects. It will make your welding alot more fun.

Everything I do can be done under a shade tree with a couple of pails, some chemicals like paint thinner and purple power, and a few basic tools. Use a tea kettle for the hot water rinse. If the part is really clean you can use the kitchen oven for the "bake". My current SS wire brush in the mag kit is a Lincoln brand from Home Depot and it works fine.

I have a set up dedicated just to prep mag parts. SS wire brushes, course burrs, carb cleaner, box of paper rags. Most parts start out going throught the solvent parts washer. Then I remove paint and grind the weld area. Next they go to the water parts washer where they get a degreaser bath, double rinse, and hot dry. After they come out I bake them in an oven for a few hours (some parts don't need this step). When done baking I finish grinding the weld area, wire brush the weld area, and then weld within minutes so the surface has very little time to oxidize.

Some think I'm excessive, and they're right.:hmm3grin2orange:
But in the end I've built up cases with spun bearings and re-machined them. I've welded every part of a chainsaw from air cleaner covers to guards over the exhaust pipes. More than one person has said my mag welding is top notch.

What they don't know about is my secret grave yard of burned up parts.



Mr. HE

 

[SkippyKtm]

To the OP, I only mean this in a helpful way, but your parts are nowhere near clean enough to be trying to weld them. Cleaning the weld area is a start, but having the whole part clean is almost a must with mag welding projects. It will make your welding alot more fun.

Everything I do can be done under a shade tree with a couple of pails, some chemicals like paint thinner and purple power, and a few basic tools. Use a tea kettle for the hot water rinse. If the part is really clean you can use the kitchen oven for the "bake". My current SS wire brush in the mag kit is a Lincoln brand from Home Depot and it works fine.

I have a set up dedicated just to prep mag parts. SS wire brushes, course burrs, carb cleaner, box of paper rags. Most parts start out going throught the solvent parts washer. Then I remove paint and grind the weld area. Next they go to the water parts washer where they get a degreaser bath, double rinse, and hot dry. After they come out I bake them in an oven for a few hours (some parts don't need this step). When done baking I finish grinding the weld area, wire brush the weld area, and then weld within minutes so the surface has very little time to oxidize.

Some think I'm excessive, and they're right.:hmm3grin2orange:
But in the end I've built up cases with spun bearings and re-machined them. I've welded every part of a chainsaw from air cleaner covers to guards over the exhaust pipes. More than one person has said my mag welding is top notch.

What they don't know about is my secret grave yard of burned up parts.



Mr. HE

Thanks for the good advice, yep, I must admit, I need to clean before welding much better, I haven't any training from anyone, so any advice is welcome! Live and Learn is what I always say:msp_rolleyes:

In case anybody hasn't seen this about NOT using brake cleaner for TIG welding, I wanted to post this link:

http://www.brewracingframes.com/id75.htm

I once used brake clean to pre-clean before using a mig welder with a straight Co2 setup. Although the vapor probably wasn't phosgene, it sure was terrible smelling stuff, and it made me want to vomit. Needless to say I won't be using brake clean for cleaning before welding again.