Anyone do a lot of machining of welds on steel?

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I'm looking at building up cast steel that is badly worn and re-machining it to it former self.Anyone have any tips? So far, my understanding is that I need to heat the piece to ±300º F. for welding. I need advice on filler rod and burn it tips. I have to fill holes about 1" Ø and .75" deep. To small for my mig tip and cramped for tig and rod.... One idea I have is to ream out hole 1/8" oversize and sleeve and weld in the sleeve, whatdoyathink?
Reply:Cannot visualize what you are trying to repair.Yes i would preheat and bury in DRY sand immediatly after welding and leave overnoght.I would TIG weld if possible. Lowest heat input.If a lot of material needs to be built up then i would stick weld.Wire feed will give you the fastest build up but has a high heat input.Last edited by Donald Branscom; 10-26-2008 at 06:29 AM.AWS certified welding inspectorAWS certified welder
Reply:It depends on what the part is and what alloy it's made of, whether you can manipulate it while welding, how good you are with the different processes, whether the holes are blind or through, etc. Can you show a photo of the parts?   Is this the links on the Little Giant? If so, how out of round or oversize are the holes?
Reply:If I understand you correctly I think you would be far ahead boring out the holes and sleeving them than trying to weld them up.I'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:Oldiron2Yes this is the link on the Little Giant, its on of the arms in the photo. Donald B. There are no blind holes, see photos. Thanks for the tip to place in sand after heated and welding. As you can see from the photos, no blind holes. The holes have been bored at off angles and caused the faces to be worn at off angles as well. I don't know what the alloy is. The machine was made in 1929. Sid, from Little giant said to "Preheat to 300 or so and weld with mig, gen purpose rod, nothing special"So, I guess my question is, what is general purpose rod and is that machinable with HHS cutters or do I need Carbide. I've never machined welded steel before. In my past experience, welds are harder than the base steel so I'm concerned about getting good cuts from the machining.Thanks for your help. Attached Images
Reply:Originally Posted by fewoodI'm looking at building up cast steel that is badly worn and re-machining it to it former self.Anyone have any tips? So far, my understanding is that I need to heat the piece to ±300º F. for welding. I need advice on filler rod and burn it tips. I have to fill holes about 1" Ø and .75" deep. To small for my mig tip and cramped for tig and rod.... One idea I have is to ream out hole 1/8" oversize and sleeve and weld in the sleeve, whatdoyathink?
Reply:Assuming your holes aren't off by much, I would agree with Zapster--in fact, I think that was my suggestion when you first asked in the other post. It looks as if the links have plenty of 'meat'. You can use a little dry ice dissolved in acetone to freeze and shrink the sleeves so they just 'drop' in,  then TIG weld the ends and ream. If you decide you want a thinner walled bushing, get/make one with the appropriate OD but with a smaller ID and drill/ream it after installation. A thicker bushing might be easier to drive if you don't freeze-shrink it, but I don't know about needing to change the interference fit with a thicker bushing.Don't forget to redrill the oil holes.You might want to practice on a piece of material similar to the links, just so you do it perfectly on them.
Reply:BTW, you might double check to see that the moving/sliding parts are properly centered compared to the fixed parts, that is, that the castings were all done correctly so the links don't have to be off a bit to get other parts to line up as they should. I've seen that problem with other old equipment once or twice.
Reply:After seeing it, and realizing what it is i would not weld at all.I would use a slow speed reamer then put in bronze oilite sleeves.Replace clevis pins.I would machine the solution .No welding.AWS certified welding inspectorAWS certified welder
Reply:Thanks guys your input has been very helpfulSeems like sleeving is the way to go, replaceable etc.Oldiron2,Thanks for the input. I have checked alignment issues and they are out of alignment. Filling the surface to be trued properly will be easy. Setting new sleeves will be easier than trying to partially fill holes and re-bore. I can also use softer steel for the pins as I will know how hard the sleeves are. What is the formula for dry ice and acetone, I've never heard of that. What is a good machinable filler rod? Currently running ER70S-6 in my Miller 252, will this machine well?
Reply:Donald-Do you think oilite bronze would hold up with the pounding this machine puts out?I have been thinking about that as well. Possibly make them replaceable, too.I do have to build up the shoulders because they need to fit other parts, but that will be way easier