Husqvarna 51, cracked magnesium case

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Day one cutting the 15 cord semi load and my Husqvarna 51 started leaking bar oil out the left side and wouldn't start the next day. (I think the coil got ruined by the oil)Took the recoil and coil off and this hole is what I found.  I stuck the pick in the hole so it'd be easy to see I believe the case to be magnesium - any thoughts on fixing it?  Tig?  Epoxy?Notice other areas are also degraded (missing paint areas).Good thing my 70's model Jonsered 52e always runsDave J. Attached ImagesLast edited by MinnesotaDave; 07-11-2013 at 10:52 PM.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:Update:Just looked up cost for magnesium tig rods, it's cheaper in the long run to order a used replacement case half for the saw.$87 for 1/2 lb +tax and shipping makes tig repair cost more than the used part would be.  Did not know it cost that much - assumed it would be close to aluminum or stainless prices.Dave J.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:It may be aluminum Dave.  Get some fine shavings and hit them with a propane torch.  If the ignite, they're mag. Check with the manufacturer.  Everyone told me my Stihl 066 was a Mag case when in fact it was Aluminum.  Those Mg rods are crazy expensive. I'd personally JB weld it.  My big question is the mechanism of that injury.  How did that crack/hole occur?  Are you sure the coils bad, or did the hole create a vacuum leak in the case?If you wanna tig it, someone on here could probably lend a helping hand and toss you one tig rod.TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:I can give you a couple of tig rods ( I'll cut 'em short so they'll fit in an envelope)  if you're interested. I won't be back in the shop 'till Monday tho....Mike
Reply:Originally Posted by Drf255It may be aluminum Dave.  Get some fine shavings and hit them with a propane torch.  If the ignite, they're mag. Check with the manufacturer.  Everyone told me my Stihl 066 was a Mag case when in fact it was Aluminum.  Those Mg rods are crazy expensive. I'd personally JB weld it.  My big question is the mechanism of that injury.  How did that crack/hole occur?  Are you sure the coils bad, or did the hole create a vacuum leak in the case?
Reply:i'd clean it good and use jb-weld epoxy.miller thunderbolt 250vlincoln square wave tig 175 prolincoln idealarc mig sp250everlast tig 210EXTeverlast power plasma 50chicago electric (hf) 130 tig/90 arcchicago electric 90 amp flux wire3 sets oxy/acet
Reply:Another vote for a epoxy type repair, after all its just the oil tank and not the crankcase.Around here the saws are pretty common lots of junked ones, auctually i'm pretty sure i got a blown up one in the shed but it may be a 50.Briggs weldnpower 225/210/cvLn-25 suitcaseMillermatic 130
Reply:That damage kinda looks like it was exposed to an arc - possibly from the coil . Is that where the coil mounts?Gizzmo
Reply:Originally Posted by gizzmoThat damage kinda looks like it was exposed to an arc - possibly from the coil . Is that where the coil mounts?Gizzmo
Reply:I am in no way an expert, as I am as inexperienced with welding as my join date suggests, but I do know that magnesium and aluminum are alloyed together sometimes.  This may yield an alloy that won't burn so it could still be mostly Mg even if it doesn't light.  Just a thought.
Reply:Before I forget. When you do get the rods and start welding, watch your ground. Make sure it's well fastened on a clean piece of the casting. Magnesium seems to be particular about it, more so than anything I've welded.The fist saw I ever welded turned out good....except where the ground clamp had burnt thru it.....Mike
Reply:Originally Posted by gizzmoThat damage kinda looks like it was exposed to an arc - possibly from the coil . Is that where the coil mounts?Gizzmo
Reply:Sounds like I'll pick up a coil too Thanks for the input guys - would not have considered an arc burn since the saw ran fine the day before.Pretty good saw - miss how light it is compared to my 52E.  Will be an interesting challenge Dave J.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:You can test it with Vinegar, it'll react differently on magnesium than it will on Aluminum...Or clean up a spot and hit it with the TIG machine, if the arc turns green, its magnesium... Good luck [Account Abandoned 8/8/16 Please Do Not Attempt Contact Or Expect A Reply]. See you on YouTube! -ChuckE2009
Reply:Did not know that Lanse - excellent tip Dave J.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:Dave if you pay the shipping I will send you the parts you need. I did not read the thread.
Reply:Hey Mike, that would be cool if I am unable to weld it using the rods mrmikey is sending me.Very nice offer that I will take you up on if my welding skill is not up to the task. Dave J.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:Update:  I welded the case with the rods mrmikey sent.  It went fairly well...until I overheated near the bar/chain oil hole.  It's warped now.Rojodiablo - it was definitely not easy, I sandblasted inside and out, then used acetone.  Still not quite clean enough to weld right. Well, it was an excellent learning experience and I would weld magnesium again.  But I would not tackle this type damage, in this location, on a chainsaw again.After cleaning - the damage was much worse actually.  There were 4 holes and others about to start.  I tried it anyway Dave J.Last edited by MinnesotaDave; 08-02-2013 at 06:17 PM.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:The damage after cleaning.Dave J. Attached ImagesDave 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:Originally Posted by MinnesotaDaveThe damage after cleaning.Dave J.
Reply:Salt?  Well, in Northern MN the salt on the roads gets brought into the garage in large quantities so that would be easy to have happen.Set the saw down next to the truck and splash a little snow/ice/salt mix and there it is.The learning curve was not horrible since there were a few similarities to aluminum.  Weld location was not good though.One difference of note: where aluminum seems to want to jump on the tungsten, magnesium did not.  Arc could be super short.I'll remember about the box, that seems like it would help Dave J.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:Road salt explains it pretty well! When I was racing motorcycles, we had a lot of magnesium parts. Even one set of carbs we had were magnesium; beautiful, and EXPENSIVE. All our stuff would corrode in relatively short time frames. Footpegs, triple clamps, tabs and engine case side covers/ valve covers. After a short time, they all showed surface corrosion. When I asked, I was told we were close enough to the ocean that salt air was the cause. Since the pegs and such were sacrificial parts, we did not coat nor anodize them. They would oxide coat themselves within a few weeks. Within a few months of use, everything that had no coatings on it showed some small pitting just like aluminum shows after years. Nothing to rot and fall off, but interesting to learn a little about it.Those carbs cost about $10K in 1989 money; they were bathed in spray on lube similar to WD-40.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Originally Posted by MinnesotaDaveDid not know that Lanse - excellent tip Dave J.