359 case repair advice needed

[MAF143]

A buddie has a broken front AV mount on his 359 PTO side case. Can this be repaired by welding or does it need replaced? I've not had much luck finding a case for him so far. I've seen some miracle workers @srcarr52 on here...

 

[srcarr52]

Yes, that can be welded.

 

[300whisper]

Similar problem here. Bought pile of parts and there was 357XPG carcass with both case halves cracked. Flywheel side is easy one, but clutch side is bit challenging, crack goes to front bar stud. It sure isn't worth welding but I really want to try. I would appreciate if someone could give rough amperage and what filler rod to use.

 

[MAF143]

Yes, that can be welded.

Thx,
I'll get started tearing the saw down. I'm assuming the case will need split and everything removed to weld it. Will the bar studs need to be removed or can they be left in place?

 

[Duce]

Yes, that can be welded.

And you are the man to do it! You fixed my 592 and thanks again!

 

[MAF143]

I think Dave has a local welder lined up to do the weld but he said it's the first time he's ever welded an oily chainsaw. Are there any tips specific to chain saws I can pass along without insulting him. I'm sure he's a pro and very good at his job.

I'm sure there are welder jokes that can be inserted here like the carpenter sending a newbie like me after a board stretcher or left handed monkey wrench... LOL

 

[David Young]

I haven't done mag welding personally. Its described as like welding aluminum but trickier. I know it is best to clean away the paint, and degreasing is huge on chainsaws because of the oily contaminants. Acetone or denatured alcohol are good to degrease and not leave a residue. I am sure the welder knows but never hurts to mention do not use chlorinated solvents. Some brake cleaner is chlorinated. When it is welded it creates phosgene gas.

This is about the most help I can be...

 

[300whisper]

I think Dave has a local welder lined up to do the weld but he said it's the first time he's ever welded an oily chainsaw. Are there any tips specific to chain saws I can pass along without insulting him. I'm sure he's a pro and very good at his job.

I'm sure there are welder jokes that can be inserted here like the carpenter sending a newbie like me after a board stretcher or left handed monkey wrench... LOL

I prepared cases in blasting cabinet with aluminum silicate, then put them in ultrasonic cleaner for half an hour, dishwashing liquid and hot water. Final rinse with acetone just before welding. All I need is right filler rod and amps.

 

[farminkarman]

I prepared cases in blasting cabinet with aluminum silicate, then put them in ultrasonic cleaner for half an hour, dishwashing liquid and hot water. Final rinse with acetone just before welding. All I need is right filler rod and amps.

I've used ERAZ92A filler on a couple saw cases, but I'm not an expert. I set my tig welder to 150 but then used the pedal to control the puddle...not real sure how many amps I was actually using once the puddle was going.

Edit: I ended up with 1/8" filler rod...in retrospect, I would have preferred having 3/32" for this type of work.

 

[farminkarman]

I think Dave has a local welder lined up to do the weld but he said it's the first time he's ever welded an oily chainsaw. Are there any tips specific to chain saws I can pass along without insulting him. I'm sure he's a pro and very good at his job.

I'm sure there are welder jokes that can be inserted here like the carpenter sending a newbie like me after a board stretcher or left handed monkey wrench... LOL

I didn't find it too difficult to weld. I did heat the area pretty good a few times to sweat the oil & junk out of the crack. I did a finish clean of the surface with acetone, and scrubbed the filler rod with a scotchbrite pad and acetone before starting the weld.

 

[Firewood Hoarder]

I think Dave has a local welder lined up to do the weld but he said it's the first time he's ever welded an oily chainsaw. Are there any tips specific to chain saws I can pass along without insulting him. I'm sure he's a pro and very good at his job.

I'm sure there are welder jokes that can be inserted here like the carpenter sending a newbie like me after a board stretcher or left handed monkey wrench... LOL

I've welded up similar oil-soaked stuff, and the biggest thing as others have said is cleaning and surface preparation. Light sandblasting to remove paint in the area, followed by as thorough a cleaning as possible with acetone or non-chloriniated brake clean. Then clean again after you are positive it is clean. Cast parts can be somewhat porous and can hold oil within the metal's pores.

Actual amperage I couldn't tell you, as I used a TIG set to 200, but I was watching the puddle and using a pedal. No clue where it was when I was sticking it back together.

 

[300whisper]

I've used ERAZ92A filler on a couple saw cases, but I'm not an expert. I set my tig welder to 150 but then used the pedal to control the puddle...not real sure how many amps I was actually using once the puddle was going.

Edit: I ended up with 1/8" filler rod...in retrospect, I would have preferred having 3/32" for this type of work.

Thank you Sir, that is very helpful.

 

[srcarr52]

Thx,
I'll get started tearing the saw down. I'm assuming the case will need split and everything removed to weld it. Will the bar studs need to be removed or can they be left in place?

No need to tear it all the way down for that area, it's far away from any gaskets and seals that could be damaged from heat. Leave the bar studs in, they are a great place to attach your ground clamp to.

I usually clean them with degreaser and bead blast the area if I can. Keep a dedicated stainless wire brush around to knock any suit off.

ERAZ61A or ERAZ92A filler rod. I like to use 1/8" rod as the thinner the filler the easier it is to catch it on fire if you're holding it too close to the torch but far enough away to be out of the shield gas. The filler rod is very expensive.

AC current with the balance at close to 50/50, too much cleaning action will create a lot of pores in the weld and mag seems to like lower frequency around 90hz. For that area you'll probably be 125 amp or less. Use a big champagne gas lens with lots of argon flow!

I usually go over the weld area once with the tig torch to burn out any residual oil, then wire brush it off before starting to add filler.

 

[farminkarman]

No need to tear it all the way down for that area, it's far away from any gaskets and seals that could be damaged from heat. Leave the bar studs in, they are a great place to attach your ground clamp to.

I usually clean them with degreaser and bead blast the area if I can. Keep a dedicated stainless wire brush around to knock any suit off.

ERAZ61A or ERAZ92A filler rod. I like to use 1/8" rod as the thinner the filler the easier it is to catch it on fire if you're holding it too close to the torch but far enough away to be out of the shield gas. The filler rod is very expensive.

AC current with the balance at close to 50/50, too much cleaning action will create a lot of pores in the weld and mag seems to like lower frequency around 90hz. For that area you'll probably be 125 amp or less. Use a big champagne gas lens with lots of argon flow!

I usually go over the weld area once with the tig torch to burn out any residual oil, then wire brush it off before starting to add filler.

Well, maybe its a good thing I got 1/8" filler rod, . That would be exciting to have a magnesium rod burning out of control.

 

[srcarr52]

Well, maybe its a good thing I got 1/8" filler rod, . That would be exciting to have a magnesium rod burning out of control.

If you do catch it on fire snuff it out with the argon from your torch... don't try to blow it out like I usually try first!