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Re: Welding up shafts with a MIG.

Originally Posted by propanehotrod

It can be done and I have done it a lot.
Usually its just an area where a bearing spun or possibly a seal.
The trick to keep it straight is to weld paralell to the axis of the shaft.
Start at 12 o clock Then 6 then 9 and 3.
Once you have the first four welds Then just start welding next to them this time 12,3,6,9 and keep going until you are done.
If it gets RED hot or too hot to control, stop and wait a bit but dont let it get cold. Keeping it hot until its done helps anneal any hard spots.
It can be done with Mig Tig or Stick.

thats exactly how i used to do it (12-6-9-3 o'clock). i had trenchers, allways bearings/seals problems w/ all that dirt. id preheat to help w/ warpage, and sometimes before finshing, i'd roll them by hand on crude v blocks outa angle iron, w/ a cheap dial indicator off a magnetic base, in the process, trying to help control warpage, as some splined into right angle gear boxes (similar to auto rear ends) and extend out, w/ a drive sprocket. i didnt have a mig welder in those days, so 6013 it was, cuz it layed and machined nice.

Re: Welding up shafts with a MIG.

You may need to straighten after welding. Most of shaft I have welded I to straighten after welding. Some times I just new shaft.

Dave

Originally Posted by mcostello

Now and then Someone brings in a shaft to be welded up. I have a Lincoln IdealArc 250/300. I also have a Hobart 140 MIG. Would it be recommended to weld up the shafts using the Mig? I can preheat, not having flux would make a better job of it. Recommendations?

Re: Welding up shafts with a MIG.

Heck yeah, he knows how to get it done

If you watch the end of his videos where he gets tongue tied, it's not heck yeah it's, " F**k yeah" LOL.
He made a faq video a while back, he's self taught, runs his own shop and works by himself, smart man...............Mike

Re: Welding up shafts with a MIG.

Originally Posted by M J D

That mig you have will be fine. You don't need or want much heat. I would run beads parallel to the shaft. Run a bead, turn 180 degrees and run another. Keep alternating sides to help keep the shaft straight. After it cools and before machining check and adjust accordingly for straightness.

I agree, I've used a 120v mig on small shafts just like you described.

Then ground them down by eye and smoothed with a flap disc (low speed use).

I have lathe now - lol

Re: Welding up shafts with a MIG.

Originally Posted by mrmikey

If you want to see someone good at building up/line boring shafts and bores and who knows his s**t, look up Cutting Edge Engineering on youtube..........Mike

Heck yeah, he knows how to get it done

Re: Welding up shafts with a MIG.

That mig you have will be fine. You don't need or want much heat. I would run beads parallel to the shaft. Run a bead, turn 180 degrees and run another. Keep alternating sides to help keep the shaft straight. After it cools and before machining check and adjust accordingly for straightness.

Re: Welding up shafts with a MIG.

This is primarly for small shafts around 1" --1 1/4". A friend bought in one that was 1 7/16", could not be taken apart and was lagged and the plant was down etc, etc. My stick welds are going have to get better or use the Mig which is easier for Me to see.

Re: Welding up shafts with a MIG.

Originally Posted by mcostello

I was wondering if a Hobart 140 had enough guts for the job. Sorta like the threads about welding a trailer with My new 5 amp flashlight battery MIG machiner.

Depending on the size of the shaft it could work but I think you'd want to preheat the shaft for the fist pass. A pic. of what you want to do would help.

Re: Welding up shafts with a MIG.

Sub-Arc flux can be ground and reused. Never sweep it up with a corn broom though because they can't get the broom remnants separated from the flux. If you ever want to get flashed really good, see a sub-arc weld run out of flux. If you ever want a nasty repair, have a sub-arc burn through on a shell for a tank or vessel. You can't see if it's about to burn through because of the flux. By the time you get it stopped there's about a 2 inch nasty gap to repair. Even worse is if it has to pass x-ray.

Re: Welding up shafts with a MIG.

Originally Posted by CAVEMANN

Our Boiler shop used a submerged arc unit to repair badly worn mill trunnions, the machine was set up on an old lathe , it laid down wire under a powdered flux that made a beautiful weld to machine, it seems like the wire was about 1/16 diameter, flux flowed & dropped onto the weld and fell off as it cooled, they caught the flux & screened the powder back out of the slag & reused it.

Years ago a local machine shop had a setup like that to build up dozer rollers and idlers with Sub-Arc, they did a fair amount of shaft work too. Now they are out of business because labor costs more than the Italian replacement parts.

Re: Welding up shafts with a MIG.

Originally Posted by old miner called Pop

I would think that would work, our line boring guy uses mig to build the bores back up before he cuts them, he uses a machine made by an outfit called climax to do it....pretty neat setup. The wire comes through a tube and rolls around the bore makin a nice pretty weld thats easy to cut. He cuts the work hardness out of it first then preheats it. I think its .035 wire he uses and I know its a 75/25 mix he uses.

Ive done the bores and pins for the buckets with 7018 but it takes longer and doesnt do as nice a job, but Ive never done a long shaft, a machine shop hand would probly know more about it

Maybe this helps maybe not Im no expert at it

Climax specializes in line boring equipment, we had a couple of their macines in the smelter where I worked.

Re: Welding up shafts with a MIG.

Our Boiler shop used a submerged arc unit to repair badly worn mill trunnions, the machine was set up on an old lathe , it laid down wire under a powdered flux that made a beautiful weld to machine, it seems like the wire was about 1/16 diameter, flux flowed & dropped onto the weld and fell off as it cooled, they caught the flux & screened the powder back out of the slag & reused it.

Re: Welding up shafts with a MIG.

I was wondering if a Hobart 140 had enough guts for the job. Sorta like the threads about welding a trailer with My new 5 amp flashlight battery MIG machiner.

Re: Welding up shafts with a MIG.

Originally Posted by Welder Dave

Depending on how bad the shaft is worn and the material, it is often called metalizing. I don't know what the maximum thickness they can build up is but if not too deep, they machine the surface to build up clean, maybe a little rough, and then heat the shaft red hot while spinning in a lathe, Then they use an oxy/fuel torch(spray torch) with a powered metal of appropriate hardness to build up the shaft. I had the shaft in the rotary swing cylinder in my backhoe built up this way. Cost about $300cad but saved me $2000 or more on a new shaft if one was even available. For a general shaft MIG should be fine as long as you preheat if it's a large shaft. Would be nice if you could spin it while welding. Mig is generally a little harder than stick. Depending on the shaft you might consider using build up rod that is harder and doesn't mushroom. It will need the proper tooling for machining to size. There's a video on here showing metalizing/spray welding a shaft back to size.

ABomb did a great You Tube video of spray build up.

I'll presume the advantage is equal heat distortion on all sides, less risk of bending.

Years ago I had a group of Dayton farm duty electric motors All had come from Grainger with shaft loose in the rotor. A local small machine shop sent the shafts off to be welded. They then machined down to size & pressed them in.

Other motors I used Locktite Red with good results.

Re: Welding up shafts with a MIG.

Depending on how bad the shaft is worn and the material, it is often called metalizing. I don't know what the maximum thickness they can build up is but if not too deep, they machine the surface to build up clean, maybe a little rough, and then heat the shaft red hot while spinning in a lathe, Then they use an oxy/fuel torch(spray torch) with a powered metal of appropriate hardness to build up the shaft. I had the shaft in the rotary swing cylinder in my backhoe built up this way. Cost about $300cad but saved me $2000 or more on a new shaft if one was even available. For a general shaft MIG should be fine as long as you preheat if it's a large shaft. Would be nice if you could spin it while welding. Mig is generally a little harder than stick. Depending on the shaft you might consider using build up rod that is harder and doesn't mushroom. It will need the proper tooling for machining to size. There's a video on here showing metalizing/spray welding a shaft back to size.

Re: Welding up shafts with a MIG.

Attachment 1729665
Attachment 1729666
Attachment 1729667
This was a stainless shaft about 3" Rush after hours emergency The world is ending we need it now!

Re: Welding up shafts with a MIG.

It can be done and I have done it a lot.
Usually its just an area where a bearing spun or possibly a seal.
The trick to keep it straight is to weld paralell to the axis of the shaft.
Start at 12 o clock Then 6 then 9 and 3.
Once you have the first four welds Then just start welding next to them this time 12,3,6,9 and keep going until you are done.
If it gets RED hot or too hot to control, stop and wait a bit but dont let it get cold. Keeping it hot until its done helps anneal any hard spots.
It can be done with Mig Tig or Stick.

Re: Welding up shafts with a MIG.

For building up worn shaft, I'd favor TIG.

Re: Welding up shafts with a MIG.

I built up some worn very old Wheelhorse garden tractor spindles using .023 S6 and my Lincoln SP135. That part worked great, it was building a jig to mount them in the lathe to turn them back down that was fun.

Re: Welding up shafts with a MIG.

Originally Posted by mcostello

Now and then Someone brings in a shaft to be welded up. I have a Lincoln IdealArc 250/300. I also have a Hobart 140 MIG. Would it be recommended to weld up the shafts using the Mig? I can preheat, not having flux would make a better job of it. Recommendations?

I did one once in a pinch because a new one was other end of the country, it was needed THAT day. MIG worked very well, but shaft wasn't straight. I heat & hammer straightened it by eye, then fine tuned straight with acetylene & oxygen torch only. It was still working fine 6 weeks later when we installed the new shaft.

Re: Welding up shafts with a MIG.

If you want to see someone good at building up/line boring shafts and bores and who knows his s**t, look up Cutting Edge Engineering on youtube..........Mike

Re: Welding up shafts with a MIG.

I would think that would work, our line boring guy uses mig to build the bores back up before he cuts them, he uses a machine made by an outfit called climax to do it....pretty neat setup. The wire comes through a tube and rolls around the bore makin a nice pretty weld thats easy to cut. He cuts the work hardness out of it first then preheats it. I think its .035 wire he uses and I know its a 75/25 mix he uses.

Ive done the bores and pins for the buckets with 7018 but it takes longer and doesnt do as nice a job, but Ive never done a long shaft, a machine shop hand would probly know more about it

Maybe this helps maybe not Im no expert at it

Re: Welding up shafts with a MIG.

Sub’d to see what the experts recommend.

Welding up shafts with a MIG.

Now and then Someone brings in a shaft to be welded up. I have a Lincoln IdealArc 250/300. I also have a Hobart 140 MIG. Would it be recommended to weld up the shafts using the Mig? I can preheat, not having flux would make a better job of it. Recommendations?