magnesium crack

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I have made it a point to stay away from magnesium since the accident with my old chain saw...A coworkers son has a cheap dirt bike and he wiped out and the shifter cracked the clutch housing cover. We've tried a few epoxy products that have worked before but once the epoxy cures for a week or so it'll separate from the cover. I'm just guessing the expansion/contraction rate is too far apart for any epoxy to hold. The part is easy to remove and I've even pressure washed it after a cycle through our safety kleen jet wash. Used 80 grit by hand and still get a leak after a week. I am pretty decent with a tig on aluminum and use the pure green tungsten usually on the aluminum. Is tigging magnesium similar to aluminum?I didn't want to try but he has no money for a replacement and it's small enough if it were to start burning I could let it burn out.  I'm planning on trying it outside sometime this week. just wondering if anyone has any advice or thoughts before I try. I'll probably use my older air products 300 transformer machine, I can use my cousins dynasty if it'd be better, I just have the feel for my air products or my a/bp 330.it's just a small crack and if it were aluminum I'd probably just run the tig along the crack to fuse it back together. I'll snap a pic of it tomorrow if he brings it in.  it's just a cover. no structure or safety concerns besides setting it on firethanks for any inputBlue stock- shopmaster, a/bp330, maxstar 150stl, maxstar 210, hf251, Tbolt ac/dc, mm 135Red stock-ranger 8, weldanpower 150, idealarc 250 ac/dcEsab plasma, Victor OA set, Air products ac/dc 400 ampIt's me flipped in snow..doughnut fail
Reply:Well if u meant that u would just no filler fusion weld the aluminum then think again. U have to use filler on aluminum. At least most of the weldable varieties i know of. Ive heard u just need to keep it cool and dont over heat/weld on magnesium. Would love to see pics of the attempt whether it works out or notDynasty 200DX   (2014)Millermatic 211 (2015)Optrel 864   (2014)Smith Medium duty MBA 30510 (Xmas 2014)Tennsmith 16ga 4ft finger brake (2015)Trailblazer 325 EFI and excel Thermal dynamics Cutmaster 82Miller maxtron 450
Reply:It's pretty different - where aluminum tends to almost be "attracted" to your tungsten, magnesium seems to stay away from it.It basically possible to "bury" the tungsten in the puddle.Google some videos on the subject and you will see the difference.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:thanks guys...I'll get to a computer with real Internet and watch some  videos, I was thinking of welding the inside of the cover and using clay as a helper for heat control..I think I can press it into a bucket of clay to help with heat transfer but this will be my first try at magnesium. may end up a total disaster but I would like to try to help him
Reply:I did a similar repair on a triumph that my friend dropped once. it was a cast aluminum cover and it was fairly thick, probably close to 1/4 inch and it held oil with just a pass on the tig with no filler
Reply:Same settings as alum. You do need to add filler. The metal melts greenish and fumes out so yes keeping a short arc length helps keep it from fuming so much. Every two inches or so you should stop and brush off the smut that accumulates or it just welds dirty. It won't take long to figure it out. The hard part is getting filler rod a couple of lengths at a time. The stuff is expensive. I use ER-AZ61a. Got a job in right now that will be using some 3 lbs. Keep an eye out for any fire that starts and put it out with your argon post flow. But keep an appropriate fire extinguisher handy. I have a bucket of sand on standby. PM me if you have a hard time finding rod.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:pics will be posted regardless of the results for sure. I really do appreciate the help
Reply:Originally Posted by shovelonSame settings as alum. You do need to add filler. The metal melts greenish and fumes out so yes keeping a short arc length helps keep it from fuming so much. Every two inches or so you should stop and brush off the smut that accumulates or it just welds dirty. It won't take long to figure it out. The hard part is getting filler rod a couple of lengths at a time. The stuff is expensive. I use ER-AZ61a. Got a job in right now that will be using some 3 lbs. Keep an eye out for any fire that starts and put it out with your argon post flow. But keep an appropriate fire extinguisher handy. I have a bucket of sand on standby. PM me if you have a hard time finding rod.
Reply:Originally Posted by Michael rayour lws sells it. just have to buy a pound as a minimum. sand will be on hand. it'll be attempted outside 30 ft from the shop door. and the bad thing is the crack is only about 1/2 inch long. it's not bad at all..I can't believe none of the epoxy held.thanks for the help
Reply:I have no clue about the cost of the filler rod. In this case I'm betting I can find a replacement for it for cheap off ebay.. I'm still going to give it a shot unless that filler is really high. I'll post a pic of it before I go for it first, I really do appreciate the help on the subject and I know the kid will be thankful as well. He makes a real effort to take care of it and he keeps it spotless...washes everything after every ride.  thanks again guys.
Reply:I'm a regular at the lws. they know me pretty well and they always have been good to me. I've just never wanted to try magnesium. I always pay cash and they've even traded bottles in my favor several times..my dad was friends with one of their higher up guys years ago. No complaints about my lws. I know a pound is the minimum of filler they sell for ss and aluminum so I just figured it'd be the same way for mag, but since it's less common I'm pretty sure he will just slide me a rod or two to try.  I'll stop by on my way to work in the morning and see.
Reply:Originally Posted by Michael rayI have no clue about the cost of the filler rod. In this case I'm betting I can find a replacement for it for cheap off ebay.. I'm still going to give it a shot unless that filler is really high. I'll post a pic of it before I go for it first, I really do appreciate the help on the subject and I know the kid will be thankful as well. He makes a real effort to take care of it and he keeps it spotless...washes everything after every ride.  thanks again guys.
Reply:Originally Posted by EvilBunnyhttp://www.ebay.com/itm/3-32-AZ61A-M...UAAOSw2GlXF489    this is some filler I found on ebay real quick they have some real handy info in the description as well ( not connected to them in any way)
Reply:I do have a mag camp fire starter...no more than I need I may be able to put it in the wet band saw and cut a slice off and try that if nothing else. I'm pretty sure they'll sell me a little tomorrow though
Reply:I have had some experience with the rear housings on GMC transfer cases. They have a steel star shaped retainer that cuts through the casings from the inside out. The first one I tried to weld was a serious mess It would take heat and just as you would think it would fuse it would fall out in a puddle. A friend commented that I was using aluminum rod on a magnesium piece. Gave me maybe 10 rods and told me to try again. It welded in beautifully and has stood the test of time ... so far. I do not know the name or number of the rod but if I can remember to get it tomorrow will post back. There is nothing like good prep and having the right rod.
Reply:Originally Posted by Michael rayour lws sells it. just have to buy a pound as a minimum. sand will be on hand. it'll be attempted outside 30 ft from the shop door. and the bad thing is the crack is only about 1/2 inch long. it's not bad at all..I can't believe none of the epoxy held.thanks for the help
Reply:it it is a (cheap) dirt bike it probably isn't magnesium
Reply:Originally Posted by MinnesotaDaveI would not worry about doing it inside - much nicer conditions
Reply:I said cheap because it's old and didn't cost them much...I think it's an older Husqvarna....those were some nice bikes back when they were around
Reply:I think your biggest issue will be cooking out the gunk you put on there. In my experience, which is fairly limited as far as magnesium goes, getting that stuff out will be the hardest part. I never had any other porblems with magnesium.Yeah, I know, but it'll be ok!Lincoln Square wave 255Miller Vintage mig30a spoolgunThermal Dynamics Pacmaster 100xl plasmaSmith mc torchEllis 1600 band saw
Reply:I'm going to soak it in dawn dish soap and water then boil it in hot water. hopefully I can just get a bead stuck to it that'll stop the leak.
Reply:I swear by this stuff. http://www.amazon.com/Devcon-10110-P.../dp/B00065TMTOMiller 211Hypertherm PM 451961 Lincoln Idealarc 250HTP 221  True Wisdom only comes from Pain.
Reply:Originally Posted by John TI swear by this stuff. http://www.amazon.com/Devcon-10110-P.../dp/B00065TMTO
Reply:I have welded alot of saw & bike cases out of mag. File a small pile of filings, touch a match or lighter to it. If flames is mag, if not alum. As for filler, I have used actual mag rod, but have found old lawnboy lawnmower bases tend to weld better. As to lighting on fire, I havent had one ever light up? Post some pictures.
Reply:it's magnesium for sure.. I did scrape the edge last time we glued it. they lit up just like my camp fire magnesium block does. it did look like it burned a little different but the camp mag was by flint rod. the case shaving I lit with a propane torch. and one was on dirt and the other on steel.long story short..7.3 powerstroke..  oilpan dipstick design/  hole in side of pan with a big nut with a rubber gasket...  prone to leak...   suggested solution, pull the engine.. replace pan. I cleaned to entire area and applied devcon completely around the nut ... It has been leak free for over a year. If I ever DO replace the pan,  I will weld that bugger in there solid.  (which is what a lot of guys do) but, yeah... Devcon rocks. not cheap either though...Miller 211Hypertherm PM 451961 Lincoln Idealarc 250HTP 221  True Wisdom only comes from Pain.
Reply:You can use vinegar (dilute acetic acid) to test magnesium versus aluminum.  Magnesium will generate gas (Hydrogen so don't use a lot or do it with a stogie in your mouth) and aluminum won't.  Just clean it off and put a few drops on.Outrunning my headlights since '81.
Reply:Good call on the vinegar test Rick. I've welded one VW transmission case, the filler cost about $100 for 1 pound. The first two passes had to be ground off because of dirt and sand in the casting, but eventually it cleaned up. I don't know if the part is still in use though.SqWave 200Millermatic 190Airco 200 ACHypertherm PM45Boice-Crane Band SawVictor O/A
Reply:Originally Posted by BrazinGood call on the vinegar test Rick. I've welded one VW transmission case, the filler cost about $100 for 1 pound. The first two passes had to be ground off because of dirt and sand in the casting, but eventually it cleaned up. I don't know if the part is still in use though.
Reply:Nah, he just paid for the filler. I want to find out how it lasted since that was my first try.SqWave 200Millermatic 190Airco 200 ACHypertherm PM45Boice-Crane Band SawVictor O/A