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I am restoring a 100#  Fairbanks-Dupont Power Hammer that went through a fire and then sat out for a year.. I have been able to remove the ram and toggle arms with a minimum of trouble and have them moving freely. The problem is the drive shaft. The brake is released and not touching the drive pulley. I have been spraying regularly with PB Blaster and squirting it into the oiler holes. One problem is the oil holes are on the side of the shafts so I am not sure that oil has migrated all the way around the shaft. I then wrapped a sling around the drive pulley and lifted it with my hoist. The pull is in the direction of rotation and thought it might free the shaft but the machine just lifted up instead. So now my question…

 

I am considering attaching my arc welder leads to the drive pulley and fly wheel which sit on each end of the drive shaft. I am hoping that this will create enough heat to expand the shaft slightly and then release upon cooling. So is this crazy and/or is there another suggestion on how to get the shaft to release and turn.

 

Thanks for your help.

Fairbanks Shaft.JPG

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 I see a steel shaft that is rusty inside of babbit/brass bushings.  We know the the shaft is just supper tight because of the rust expansion versus a steel bolt being siezed in a steel part where they actually become one piece. So short of putting it upside down in 50 gallons of wd-40 or the like I think your on the right track with the forced rotation of the shaft. Just have to figure out how to apply more torque and maybe use 4 weed burners to apply heat to the bushing areas and a couple of air hammers to induce a high frequency vibration in the shaft could possibly break it loose. I dont see a gentle way of getting that huge shaft to turn. 

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If the fire was hot enough the bushings may have brazed/soldered to the shaft. In any case I would say the bearings are shot. If that's not the case applying heat may do that to them. I don't have any experience with the Fairbanks so that's a guess on my part.

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I think it is a steel shaft in a steel bushing.  From the outside, t will take a lot of heat to get through the steel casting and into the steel bushing.  Maybe I could use my forge burners instead of a weed burner. That is why I was thinking about the arc welder, so that it could heat and expand from the inside out. Looking for the safest way to heat the cast steel body of the Fairbanks.

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Steel bushinig?  Could that  really be a possibility. That just doesn't sound right to me but my wife tells me Im wrong all the time:-)  We need a Fairbanks person to chime in. 

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The Blacksmith and Hammerman's Emporium has a good section on the Fairbanks. The add says the crank has bronze bushings. I wouldn't apply too much heat to the frame but warming it up will help the PB Blaster penetrate.

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I was suprised too. In my head I was not expecting such an issue because I thought there were bronze bushings and that they looked good after the fire (no sign of heat stress) and did not think rusting would be an issue. Right after the fire, I was able to move the drive shaft. When I finally got to cleaning it up 18 months later, I put a magnet on the bushing and it was magnetic. 

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Automatic transmission fluid mixed with acetone make the best penetrating oil. Next on the list is Kroil but its $$$. I would mix up a bit of the first and give it a try. After that heat would be my next move.

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Can you put a flat faced insert in a hammer drill or impact driver and apply vibration to the shaft as it's soaking? (On the center of the ends where it won't affect anything from the impacts.)

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good idea. Because the oiler holes are on the sides of the shaft bushings I may flip the machine upside down with my hoist. I know that sounds crazy but I am not convinced capillary action is taking the oil all the way around the shaft. The vibration should help.

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i was thinking in a more radical method. Would work better if you can remove the pulley or flywheel.

Find a large nut that fits on the end of the shaft and weld it with a stick welder, inside and outside all around. 

Let the heat sink in and then start working it with an impact driver like the one used in the tyre shop, 3/4" drive. 

You may break the weld, not a problem, grind flat and weld again. A chamfer on the outside will help. And additions of penetrating oil ... transmission fluid and acetone? Sounds good, never used it. Best of luck!

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I believe Fairbanks had cast iron bushings and steel shafts. I also will second the idea of vibrating with an air hammer.  Good luck Steve!

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Thanks Judson, I will pick up a cheap air hammer and put a brass face on the driver. Lay the hammer on the floor so the oil holes are on top and start tapping and praying. I had thought they were bronze bushings and let it go during my rebuild. Time to get it going again.

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Another thing to try. Take off the front flywheel, run the nut back on to protect the threads and with a block of wood tap the shaft back & forth with a hammer. Even a few thousands of end play may break the shaft loose from the bushings.

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Are the oil holes threaded?  Either way, it might be possible to install a zerk fitting at the hole location and then force penetrating oil in under some pressure---grease fittings also work pretty well with oil, the issue is finding a gun to inject it (safety glasses!).  Some simple oil cans can do this but not under much pressure...at least a little though. 

Alternatively, you can install a tubing riser to the shop roof and get a little constant pressure--or even add a little air pressure to that to get some constant force on the penetrating oil through the oil holes.  Sometimes that can improve penetration over simple capillary action.

Ditch the PB.  The only benefit of that stuff is that it's cheap and available.  Kroil is much better (and less stinky).  Haven't tried the ATF/acetone myself so I'll go with what others have said.  

 

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I can tap the oil holes to accept a pipe fitting and put some air pressure behind the oil. I like that idea. It is better than my plan to lay the powerhammer on its side so I could get gravity to work for me.

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Make sure you get ALL the chips from tapping the holes out else they fall into the bushings and cause problems.  

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I think the oil pressures suggested would way exceed air pressures available; but it would be better than nothing!

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Kroil is Da Bomb

If you are dealing with a rust issue, what about building a containment around it and doing electrolysis?

I have also seen ultrasonics used to free up rust seized items, but not real practical for this application.

When heating, you only need to expand the outer shell by a few thousands, and weed burners work fine for that.

 

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Especially in cold weather heating of cast iron EVENLY is good idea.

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No luck yet, I bought a small auto air hammer and brazed some brass on the end of one of the tools, been tapping on the shaft, oiling and praying. No luck yet. I like the idea of the nut on the shaft with an impact hammer, might try that next. There is a bit of shaft extending out that I can weld to . I am still thinking about getting a 300 amp stick welding and clamping onto each end of the shaft to heat it up .......

 

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And then braze the tops of the journals back on when they break off? If anything you want to heat the cast iron and leave the shaft cold.

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