Magnesium tank with hole in it

[muddstopper]

I have a 346xp husky chainsaw with a hole in the oil (chain oil),tank. It seems somewhere sometime, someone put the wrong screw in the handle and it wore a hole in the oil tank. If the tank was aluminum, I would just clean it up and tig the hole shut, but it is made out of magnesium or a magnesium mix of metal. So, I am trying to decide the best fix. JBweld maybe, but would like to hear other ideals before I try patching the hole. The saw is a very good running saw and I would hate to have to scrap it, or try to find a new/used crankcase for it. Not sure trying to tig weld magnesium is within my ability and if i screw it up then the saw is toast.

 

[Shield Arc]

I don't know anything about welding magnesium, I understand the Tig rod is very expensive!:shocked: So much so some welding suppliers are selling one rod at a time because of the cost.

 

[flyerdan]

Some magnesium alloys can be difficult to weld, as if the Mg content is high it can catch fire and burn through about anything, i.e. the concrete burning bunker bombs. If it is thick enough to cut some threads, I'd drill and thread the hole, put some Loctite on a machine screw and cut off the excess with a Dremel. If it's not thick enough to take a thread, epoxy based sealers are probably your best bet, unless someone familiar with magnesium welding can chime in with some advice.

 

[Big Barn]

Shoot. Bill you're not gonna want to hear this but...

I had an almost intact 3# pack of 3/32 magnesium tig rod for sale since the summer.

No one was interested in it and I sent several sticks out free to Welding Web members who wanted to play with it. ( I had to cut into shorter lengths to keep postage down.)

A local weld shop bought the pack just a couple of weeks ago! Didn't even think to save a few.

I know, I know, thanks for nothing.....




Terry

 

[muddstopper]

Watching tigtime and welding web, it seems to tig very similar to aluminum, but I aint worth a hoot tig'ing aluminum so there you go. Even if my welding supply would sell one rod, not sure I want to risk making an even bigger hole than the one already there. The way the hole is worn, its oblong and very thin, no tapping a screw. I would like to have a piece of scrap to practice on before doing it for real, but think I will just go with the jbweld first and if that doesnt work, then I have nothing to lose if my tig skills fail me

 

[MinnesotaDaveChalmers]

I did a chainsaw case couple years ago. It is not as easy as aluminum - but it does weld.

One main difference, with aluminum the tungsten can dunk and be contaminated very easily - but with magnesium the tungsten can be nearly buried in the puddle and still not get anything on it.

It was a pretty weird welding experience.

 

[CalG]

I have a 346xp husky chainsaw with a hole in the oil (chain oil),tank. It seems somewhere sometime, someone put the wrong screw in the handle and it wore a hole in the oil tank. If the tank was aluminum, I would just clean it up and tig the hole shut, but it is made out of magnesium or a magnesium mix of metal. So, I am trying to decide the best fix. JBweld maybe, but would like to hear other ideals before I try patching the hole. The saw is a very good running saw and I would hate to have to scrap it, or try to find a new/used crankcase for it. Not sure trying to tig weld magnesium is within my ability and if i screw it up then the saw is toast.

Glass cloth and J-B weld

Clean it up well before you put the glue to it.

 

[lman]

I used JB Weld to repair my chain saw about 30 years ago and it's still holding strong.

 

[Gary Fowler]

You are going to have to put some kind of backer inside the tank or hole to keep the JBWELD from creeping inside before it cures. Since the hole is oblong, possibly drill it out larger so you can tap a screw into the hole, then put the JBWELD over the screw. Make sure you remove all the metal filings so it doesn't mess up your oil pump.
Acetone the repair site well to remove all the oil and power brush it to roughen the area up so the JBWELD has something to hold on too. Then it should hold very well.

 

[muddstopper]

Gary, been spraying down the hole site with brake clean, durn chainsaws and chain oil sure are sticky. Anyways, I think I can reach the hole thru the fill cap with my finger. While I cant get inside and ruff up the metal, I think I can at least push a little jbweld thru the hole and spread it out. Might not stick real well, but putting a mushroom head inside the tank should keep it from falling out. Plans are to use a dremel to sandpaper the outsides around the hole, clean real good with the degreaseer and just sees what happens. Magnesium rods are $80 buck a lb, dont know if I can buy just one, but if the jbweld dont work, I will start looking for one rod to try and tig the hole up with. I have several chainsaws, but I sure would hate to lose this one because of a oil leak.