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Hi fellas (and lurking ladies),I do work periodically for a commercial laundry, mostly stainless repairs on their equipment. They referred me to a company that rebuilds large commercial laundry equipment. One of their on going projects is the rebuilding of large ironers in which sheets are feed through and come out ironed on the opposite side. This company has a yard full of cast iron bases for these old ironers which have a variety of cracks that in my opinion require heating the whole piece in order to successfully repair them. These parts are all considered obsolete so repairing them is the only option in order to put these old machines back in service. I am attaching pictures of them and some of the cracks.My thinking is that since these are large pieces (roughly 4' x 8' and several inches thick), several propane heating torches can be brought to bear on the part to bring it up to about 400 degrees F. The casting would have already had the ends of the cracks drilled out and the crack itself vee'd out from both sides. Once up to temperature, I would begin the brazing process while also keeping the torches going but at a lower setting to keep the cast iron hot during the welding process. Once the brazing is finished I would lay it down and cover it with heat blankets to allow it to cool overnight.I have always avoided attempting repairs on cast iron parts that required such pre-heating as I am primarily a field service I don't have the room or tools for doing large castings such as this one. However I am going to propose that the company designate a spot in their shop for such repairs and invest in the equipment needed for heating and positioning.Any thoughts on how I propose to do these repairs? When I was a young welder in the Steel mills of South Chicago, I used to watch the older guys do repairs on large castings and this is basically how they went about it. They would let me braze on them but I never actually was responsible for the project from beginning to end.How about it?Thanks,Tony
Reply:Build a jig/clamping system to keep everything in place during the entire process. Those are load bearing joints/areas that are going to tell on you pretty quick should you make the slightest mistake. If you cant get that welded/brazed through completely your wasting your time. Preheat and cool slowly (weed burner propane torch). Build a box (where you can) and bury the heat effected area in dry sand/ash or what you have available. Heat blankets with the torch(forge type setup) would work also. I'd cool this over at least 12 hours. But that's me. I don't get paid to get in a hurry.Arcon Workhorse 300MSPowcon 400SMTPowcon SM400 x 2Powcon SM3001968 SA200 Redface1978 SA250 DieselMiller Super 32P FeederPre 1927 American 14" High Duty LatheK&T Milwaukee 2H Horizontal MillBryan
Reply:Hi Bryan,Thanks for the feedback. The picture of the entire casting shows that they are basically two halves with rods going through both of them and holding them in place in relation to each other. Questions:1) would the jig be made so as to hold the entire piece in place or just the area that needed repair? For example (based on your suggestions) I visualize a steel table where each half can be laid down onto. A heavy angle iron frame would be built upon which the piece is clamped to which would have stops and clamps at various parts with eye pads welded to it to facilitate positioning. Once pre-heated first one side would be brazed, then it would be flipped and the other side brazed. Heating torches would be on it all the time to keep the temperature while welding. See the attached modified picture showing a rough sketch (using MS Paint) of how I interpret your suggestion.Is it accurate of how you would build such a jig or what did you have in mind? Sorry for the small text. I though it would be easier to read, but alas it isn't.Thanks for the help. If I get a good handle on this project, it offers the potential for ongoing work repairing all those cast iron bases they have accumulated which at this point might as well be scrap iron.Tony
Reply:we had several large sheet mangles in the prison laundry where i work and like your's the equipment was obsolete and past it's shelf life. before our modern central laundry was built the doc hired a company that replaced some of the less complicated cracked castings with steel weldments with good results. after an inmate got his arm caught in one of the hot rollers the older machines were cut up and scrapped. the pictured casting looks pretty straight forward and appears to have no water jacketing maybe you could make a new one from steel? one other thought; building a jig to hold hot cast iron parts during brazing could be too ridgid and may cause more stressing/ cracking problems.i.u.o.e. # 15queens, ny and sunny fla
Reply:UM?Nothing to add.BUT!If you do take the job, please photo and update if possible!Looks to be an interesting repair!
Reply:Although it would take forever use ni-rod 55 and do it cold http://tinyurl.com/pmpucl5 not gonna be cheap tho. I'm no good at welding cast, I don't have the patience and have all the respect for people that do......Mike
Reply:You won't need to heat the whole thing, just around the weld and out a couple inches. I personally wouldn't heat it at all, just "U" groove it and weld it with UTP's 85FN rod. Look it up, read about how you weld with it and you will probably go with it as it takes no pre or post heat. It is expensive though, about $85 a pound.
Reply:therrera, I got in late so hope your not in a hurry. If me split those apart if you can and weld flat. Heat only the affected area. If you heat that entire piece you'll need serious ppe. That option is probably best but tuff for one guy. Scrap the kitty litter unless its the fine grit from the parts store. Expensive to say the least. Dry sand or ash or lime dependeing if code allows. Safety. Lime can be tough. Study up on heating, cooling and welding/brazing temps of cast. Pay attention to the colors when heated. Get a practice piece of similar stock. Maybe one that's beyond repair and practice on that. I would do that if I was called for the job, if I had the option.Arcon Workhorse 300MSPowcon 400SMTPowcon SM400 x 2Powcon SM3001968 SA200 Redface1978 SA250 DieselMiller Super 32P FeederPre 1927 American 14" High Duty LatheK&T Milwaukee 2H Horizontal MillBryan
Reply:have you considered spraying a nickel-based alloy?We regularly do similar repairs, and always had had great results using a HVOF-alike spraying process. unlike popular belief, mechanical properties are at least on the same level of the base material.I would say that this would be a perfect application for these castings.
Reply:You could try contacting engineering here.http://www.crownalloys.com/Bubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:If avoid that like the plague. Not only are they cracked but they have been sitting outside in the weather so those cracks are fully rusted through... Sent from my SCH-I545 using TapatalkTiger Sales: AHP Distributor www.tigersalesco.comAHP200x; AHP 160ST; MM350P, Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma. For Sale: Cobra Mig 250 w/ Push-pull gun. Lincoln Wirematic 250
Reply:Hi all,Interesting replies. I haven't sprayed metal since the 70's when I experimented with a Eutectic alloys setup when I worked for the Water District in Santa Clara County. I remember it working fine. I contacted Crown tech support and am going to be sending them some pictures of this project to see how they propose going about it. I am from the cast iron brazing school, having learned from early on to do it that way. My success with the nickel rod approach has been OK and I primarily use it on lighter cast projects. However I am open to it.I think I will propose to the company in question that I do a test repair to see how it goes. I think it would be to their advantage to spend the money to find a good repair procedure as they have quite a few of these and its money sitting in their inventory IF it can be repaired successfully. Bryan, what is PPE? You mention it in relation to heating the entire piece. The only reason I am thinking of doing so is because due to the thickness of the pieces and that there are both thin and thick areas with webs and stiffeners, etc. I would want the entire piece to expand and contract evenly. I avoid projects like this when an individual brings them to me because I don't have the space or tools to do it properly (overhead crane or fork lift, multiple heating torches, etc.). However since this is a company that is dedicated to rebuilding this type of equipment, they have the resources or can invest in them. Thinking ahead, I would have to get some type of heat suit to insulate me from the heat that thing will be throwing off when heated up for welding (if I go that route).Once a procedure is nailed down I am going to propose that they designate an area in their shop for dong these. I usually take my rig for field calls but in their case I will propose that I provide the labor to get the repairs done and they can contract me to use their equipment. On occasion clients call me and all they need is someone who knows how to do the metal work and they provide the equipment. I was "stuck" in Chicago last year for several months when I went to help a friend who was dying of cancer and I ran out of money. That's how I got by, doing jobs for people using their equipment.The rusty cracks shouldn't be a problem as I could groove them from both sides down to the bottom and then fill them in. One last thought is the "lock-stich" method I have seen where overlapping threaded studs are installed into the crack making an effective repair. I have never seen that done up close. Anyone know more on this procedure? I am open to all approaches.I'll let you know what Crown proposes.Thanks,TonyLast edited by therrera; 02-20-2014 at 11:12 AM.
Reply:even if you do repair the obvious cracks and breaks you're still left with an old casting that could break again the day after it's put back in service. i would suggest at least looking into what it would take to fabricate new one's from more dependable material. cast iron machine bases and parts that are replaced with fabricated steel weldments are stronger, lighter and cheaper. several of the lincoln procedure and welded project books show this in detail.Last edited by docwelder; 02-20-2014 at 03:07 PM.i.u.o.e. # 15queens, ny and sunny fla
Reply:Hey Tony, ppe is what you said. Heat suit, Personal Protective Equipment. That mass heated to proper temp would be like slow roasting yourself. I hope you can carve out a niche for yourself with these guys. Definitely will lead to other work in that area.Arcon Workhorse 300MSPowcon 400SMTPowcon SM400 x 2Powcon SM3001968 SA200 Redface1978 SA250 DieselMiller Super 32P FeederPre 1927 American 14" High Duty LatheK&T Milwaukee 2H Horizontal MillBryan
Reply:therrera, I was indeed talking about Eutectic (Castolin) products. I think if you find a local representative, they might be very helpful. good luck either way!
Reply:Tony, here's some info regarding Eutectic. www.castolin.com, also phone # 800-558-8524, their up in Milwaukee. Hope this helps. Bob
Reply:Hi again,well I talked with the guy from Crown Alloys. His name is Chris and he's their main in house tech support. Despite they are a specialty alloy producer, Chris suggested that the procedure I had laid out for heating the part and brazing was a good one. He referred to brazing as a "lost art". He suggested that if I "wanted" to stick weld it and avoid the pre-heat to use their product call Royal 260 and basically to follow the procedures that are common to "cold welding" cast iron.I remember back to when I worked as a maintenance welder in several steel mills in Chicago, brazing was the common (and only) form of repair for large (and small) cast iron parts. I've known about ni-rods since the early 70's and even used them a few times, but never saw them in use in the steel mill repair shops, at least during my time in them through the early 80's. Some of the castings we brazed were pretty massive by most standards, being bases for the rolling mills that took a beating 24 /7 as tons of red hot steel was rolled back and forth through dies to give them their final structural shapes.Once repaired, they did not come back. However, there were some that were TOO badly damaged and I helped the more senior welders fabricate replacements from steel as docwelder suggested. I will run the idea by the company as in all fairness the idea would not be for me to suggest repairing is the best or only way to get the job done. However the bases we replaced with steel were simple in design such as "L" shapes with gussets and so on. These however are not simple parts as they have a variety of machining steps that will be required as a second stage once the steel is jointed to duplicate the functionality. It would be much cheaper to repair than to make a new one. Whether they would last would have to be seen or researched. Also whether they would have the budget to make new ones is another.I'll give The Eutectic people a call. Thanks for the suggestion and link / phone. I'll post an update on how it goes.Thanks,Tony
Reply:Bump for post 666 Bubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:Hi all,just the final word on this "project", it never materialized. The owner never got back to me on it. So be it......
Reply:Originally Posted by therreraHi all,just the final word on this "project", it never materialized. The owner never got back to me on it. So be it...... |
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发表于 2021-8-31 22:32:24