Engine Case Magnesium Type

[KJDonovan]

All,

I just found what appears to be a pin hole in the right side engine case of my Jack Piner.  I had reassembled the engine back in the summer, filled it with oil and left in the garage on a stand while I finished my frame.  I would periodically kick it over just to keep everything moving and covered with oil.  It sat for 6 months with no leaks.  I brought into the basement on over the weekend with plans to put it on the frame last night.  Before putting it on the frame I looked it over and noticed a drop of oil on the bottom of the right side case.  I wiped it off and sanded the spot where the drop was.  To make a long story short my little bit of sanding resulted in the pin hole turning into a real bleeder.  So after doing a little research on repair methods I have decided to tear it down again and fill the porous area with weld, then dye check it to make sure I have resolved the issue before putting it back together.  My question is what type of cast magnesium are the engine cases made of?  I know there are 3 types of magnesium;
Aluminum-zinc-magnesium
Aluminum-magnesium
Magnesium-magnesium

The type of magnesium the case is made of will determine what type of tig filler rod I use when I weld it.  If anyone knows the answer it would be greatly appreciated.  Additionally, if anyone has had experience with tig welding magnesium and has tips I would apprecieate them as well.  I have done lots of aluminum, but never any magnesium.

Thanks in advance,

KD



Kevin J. Donovan
Foster, Rhode Island

[wolfmanonapenton]

I would just Marine -Tex it!Its an epoxy that works like putty hardens like steel and sands like wood,like lab metal or JB weld,but better!Wisecos,American powersports catalog use to sell it!Great for fixing cases,especially on the Sachs cover where the chain busts them out without hi-point protector?And on Egg shaped motormount bolts,mixer up pack em full,grease up motor mount bolts for release agent slide'em through,shoving excess out other side like a terd,use it to repack other mount and leave greased bolts in for a couple of days till cured,pull bolts out ,blow a propane torch through the holes for a few seconds no more tha half a minute to a minute,then mounter back in the frame! She'll stay tight with the worn bolts even!As long as you use new nylocks!They wont shake loose, as there now inexspensively have been reshimmed and fixed! Wolffee!;)Holes in cases too!I have used to fix ktm cases where water had pit them terribly?Bead blast first then fill pits up in the crank journal areas that need help let er set up and harden a bit,apply around journals using fingers wearing glove that are chemical safe and smooth it in the pitted areas like iceing on a cake,let harden ,sand a bit and cure with propane torch,slasher with clean solvent then blowwer out with the airgun on a compressor, you can even repair bearing races with the stuff! now some of you can fix parts you may thought were unfixable for atleast to have a few spares?Wolfman!:D

[KJDonovan]

Wolfman,

I am generally leery about using any epoxy to replace metal.  Does anyone else have experience with this cure?  I would hate to put something inside the crank case that could potentially breakdown and destroy the bottom end.

KD


Kevin J. Donovan
Foster, Rhode Island

[Merlin]

.............KJ,give your local AIRGAS,Praxaire or Boc gasses welding supply a call,ask for filler wire for 3/32" "wrought magnesium"(sometimes has to be ordered). Most cast magnesium is "wrought",whatever the actual mix of the parent material is of little concern for most repairs we would do as they will at the repair joint assume the basic matrix of the parent material........

[DKWRACER]

Hello Kevin, looks like some VG supporting posts, when u GR Done, I have some Red Glyptol to seal both web areas, an old trick from Kip...Tom...

[sixdazed]

Hi Kevin,The Wolfman is right,imho- marine tex is the best of the epoxys i have used and have never had a repair made with it fail (even ones i intended to be temporary!).I've repaired engine cases with chunks missing (although small ones)with no oil or air leaks.it's white though,or at least it used to be,so you may want to paint over it.if you go this route you may have to go to a boating supply or repair shop to find it though.it's heaps better than JB weld and hey its even waterproof.Oh and make sure the case is squeaky clean for better adhesion.Good call Wolfman,hey did we just agree on something?Adios,Ric

ric emmal

[john durrill]

Folks,
What temp is the Marine-tex good for? Something that can handle 350Degs F. would let you heat the cases to remove bearings with out having to re- epoxy. I have seen several cases KTM used epoxy on to fix small casting imperfections so i would think its a viable option.
John D.

[Chakka]

Im trying to download the specifications for Marine Tex now, Temp range is -60f to +300f. I have bought it in the past from Jamestown Distributors in RI. They are a marine supply place but have many items of interest to the Penton owner including West System Epoxy which I have used w/thier microballoon mixure to fix a watermellon and a toaster gas tank that had been holed and had cracked gel coat. Its an outstanding product. They also have stainless metric fasteners at a resonable price. Here is the link right to the marine tex page:

http://www.jamestowndistributors.com/find;a;1;ID;,Epoxy...Adhesives,Repair.Putties.and.Fillers,Marine.Tex,Marine.Tex

chakka

[wolfmanonapenton]

If I had a mold for making case halves,I would mix up some marine -tex,pour it in like hot cake icing and bake at abot 500 degees for about  an hour let cool trim and mount my bearings and gears and assemble paint and put in bike!fire up and race it! that stuff is stronger than Magnesium and won't crack ! It can take extreme pressure and does'nt flake or peel and is impervious to oil,gasoline and chemicals ,fix your cracked hubs with the stuff without unlacing wheels,bing float bowls where the clutch cables rub'em on the ktm bikes,use as tread repair for stripped case cover bolts,also to build up the top suface where rear of motor mount top surface chaffing!Tough!!SUPERStrength![^];)wolfman!

[Merlin]

quote:Originally posted by wolfmanonapenton

If I had a mold for making case halves,I would mix up some marine -tex,pour it in like hot cake icing and bake at abot 500 degees for about  an hour let cool trim and mount my bearings and gears and assemble paint and put in bike!fire up and race it! that stuff is stronger than Magnesium and won't crack ! It can take extreme pressure and does'nt flake or peel and is impervious to oil,gasoline and chemicals ,fix your cracked hubs with the stuff without unlacing wheels,bing float bowls where the clutch cables rub'em on the ktm bikes,use as tread repair for stripped case cover bolts,also to build up the top suface where rear of motor mount top surface chaffing!Tough!!SUPERStrength![^];)wolfman!

........looks like those idiots (sic) at KTM could use a lesson or two from some real engineering genius (sic)................................then again I'm sure an F1 team could use such an immense talent, make certain you put your quote on the resume to the F1 team, you'll secure a position for sure.......................

[KJDonovan]

All,

After reading my original post on this topic Merlin was kind enough to mail a couple of pieces of magnesium tig filler wire.  I cleaned the porous area well, and cleaned up the filler wire with emery cloth (just to make sure everything was perfectly clean) and used a ceramic backing bar on the inside of the case.  Using low amperage about 70-80 amps and 40 CFH of 100% argon the repair went off without a hitch.  Pretty much the same as welding aluminum.  After everything cooled I sanded out the repair and everything appears as good as....well in this case better than new.  Thanks again Merlin and thank you everyone else for the advice.

KD


Kevin J. Donovan
Foster, Rhode Island

[Merlin]

Refreshed

Quote: Thomas Jefferson, We are all born ignorant, some work to remain that way.
 Quote:Merlin, "it is impossible to teach those that wish not to be taught".

[dirtbike]

Of course, welding is the best repair method but I have
repaired several covers on my motorcycles with a JB weld
like product and have yet never seen any failure.

So, something else will happen to bring your bike to a halt
before a JB will fail.

I ride a dual purpose Yamaha XT 600 on a daily basis and my
JB repair on the clutch cover have crossed sweden, norway, england and scotland and logged over 1000 Km without complaining.

[Kip Kern]

Clean it, glas bead blast it, JB weld it, then use glyptal.  Check the rest of the engine as if it is found in one area, it usually is in another.  Bottom of the transmission area and lower crank area along with ignition area and clutch cover bottom.  Good Luck!  Magnesium stinks!