weld cast iron well lid?

admin

My well lid has a big crack.  I need to take it off and bring it into the shop to weld the crack.I am not sure exactly of the type of cast iron.   My thinking was to preheat it with my oxy/act torch.  Use nickle 2.5 mm electrode. Weld very short beads at a time.  Use torch to keep from cooling to fast.  Weld crack from both sides, meaning top and bottom of lid.Any help as to how to weld this thing would be greatly appreciated.  I have welded cast before but only small items compared to this well cover.  It is 40 inches in diameter. Attached Images
Reply:That's a fairly heavy casting.  You might consider brazing it instead of welding.  the joint repair will be just as strong, and there's a reduced likelihood of further cracking the casting.  I'm a little concerned by your plan to heat the casting with a torch.  That's a fairly concentrated heat source, and you're got a big piece of cast iron to heat up there.  How about setting the lid on a gas grill and using that to heat the whole casting prior to repair?  You might also consider packing it in vermiculite or glass wool to slow down the cooling process.Lastly, but most importantly, have you considered, or do you know why, it cracked in the first place?  Have you planned for how to prevent it from being broken in the future?Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Be sure to bevel it out nicely also. --Gol'
Reply:It is a very heavy lid....the reason it cracked no longer works for me!  He opened it and when he closed it he just let it drop and it cracked.  It wasn't such a big crack at first but it got bigger last winter when water froze in the crack I think.  I thought about brazing it also, good point.  I just thought welding it would be stronger, but you say not so.  I already have the nickle rod so that is not an issue.  This lid is real heavy. My gas grill wouldn't hold it up!  But it would fit inside my smoker. The proper cooling off time would be say two briskets, correct?Last edited by burnandreturn; 11-05-2009 at 11:56 AM.
Reply:Ahhh...I figured it was something like that.  Dropped, driven over by a vehicle, used for an impromptu anvil...good luck with the repair.  Post a photo of the finished repair, if all turns out well. Originally Posted by burnandreturnIt is a very heavy lid....the reason it cracked no longer works for me!  He opened it and when he closed it he just let it drop and it cracked.
Reply:How warm and how long should I keep it warm after I weld the crack?  Do I need to preheat for the brazing also? The well that this is on is really interesting.  It is actually on the under ground concrete holding tank for the water that runs in from our two springs. It is just like an underground swimming pool complete with the blue color. It is 6 meters square. 4 meters deep. You enter through this cover and go down a steel ladder to get to all the controls. Quite a project when you consider it is over 1000 thousand meters away from my home out in the woods.
Reply:id start near the center of the lid and work mmy way out to the perimeter to let it expand as it goes..
Reply:I have welded lots of cast over the years, and have found that Cronatron makes a rod called Cronacast that surpasses all other methods combined for repairing cast. No cracking, no chipping, weld in place......Check it out!   http://dawson-enterprises.com/images/April/CI04.jpgNo I am not a salesman for them.Home page  http://dawson-enterprises.com/prev_products.htm6"XX P5P8 6G
Reply:Doesn't look that bad to make one out of some plate?
Reply:If you're going to stick weld the plate, you're going to want to get it heated evenly.As far as the prep work. Depending on the thickness, I suggest prepping it from 1 side 100%. You're gonna want to U the crack out, not V it out. Drill the end of the crack to make sure it doesn't spread any further. Once the prep work is done you can worry about heating it.Typically I would set a plate of that size up off the weld bench. Then use a Weed Burner Torch maybe 2 with some propane to heat the plate evenly. I would say get the whole plate up to 800 degrees. 600 degrees in the minimum on this, so 800 gives you a saftey net.When you're ready to weld, if the cast is thick enough instead of just diving in and doing a route pass, put a layer of weld on each side of the U groove. What you're doing is putting a layer of nickle between your base metal on each side of the crack and your joining weld. Nickle is forgiving in the sense that it's soft and stretches. This is what you want when working with cast which is high in carbon and brittle. Things will be more forgiving. I would keep my weld beads 4-6 inches long and peen them immediatly after your arch goes out. Try to keep from weaving, but instead stick with the stringer beads. Be sure to keep checking your heat of the part. Don't leave it drop below 600. After you're done, Keep it covered with blankets and some insullation. To be safe leave it cool for 12 hours and keep your fingers crossed. Hope that helps.I attached a pic of a Big *** trunion housing I did this way and it worked great. I reccomend Dyeco Alloys AllCast Stick Electrode. www.dyecoinc.com and yes, I work for them. Do field service work and sell there products.Grandi Attached Images
Reply:Thanks for the help.  I was going to use a propane weed burner to heat the lid.  At first I was going to use my torch but it is too concentrated.  When done I will put it in my smoker and let it cool overnight.  As the fire burns down the temp will drop very gradually.  I might also add this lid is in Germany and I don't have access to the rods recommended. I think the rods I bought for this will work. At least I hope so, they cost me nearly two hundred dollars for two pounds. If this doesn't work out I have a stainless replacement lid and frame already but it will require a big rebuild of the top of the well.This also helps me to justify the building of my smoker so big!  Wife thought I was nuts(she's German).  Of course she said this as she was eating the best meat she had ever eaten in her life. (her  words)  Now I tell her that without this smoker I would have to buy a new top for the well at 2000 $.
Reply:You can do a Tab test to see if that rods are compatable with the Cast Iron. Clean and preheat an area on the cast. Then make a 2"x8"x 1/8" thick mild steel tab. Take the tab, stand it upright on the cast and weld one of the 2" ends to the cast the whole way around. Peen it. leave it cool to a touch. Then take a hammer and try to bend the tab over in a shape of a U so it touches the Cast Iron. If it touches and and the weld doesn't pull out of the base metal cast, you have a match. Good luck. Leave me know how you make out.Grandi
Reply:Hey burnandreturn,After reading the previous responses, it appears that most seem to think that all cast repairs are required to have a pre-heat & post-heat w/ gradual cooling. This process of repairs are done by the cast repair outfits that have the necessary furnaces & controls to provide optimum results. None of we weldors who do repairs have the luxury of this elaborate equipment & generally follow other "old-school" techniques(SMAW w/Ni99, brazing) that do have some success, although a small percentage. Keeping a casting no more than warm to the touch will result in success.I researched a technique in one of the old Lincoln books & some postings with a process called "Cold Welding Cast With MIG". After some testing on multiple applications such as intake/exhaust manifolds both auto & boat, old wood/coal stoves, and several engine blocks, I utilize this process with total success so far. I use .030" 309 MIG wire with 98/2(Ar/CO2). The 309 wire has a carbon content of 0.012. I will concur with member Grandi as to doing a "U" groove, although a "V" groove will work also, & a small hole drilled at the end of each crack. I grind bare & clean 1/2" on each side of the crack. With the casting at room temperature, I start my bead from the center & proceed to the outer edge as was also suggested. Depending on thickness, I run from 60-90A, & run a 1" bead with the "pull" technique at different locations if multiple cracks. I use my chipping hammer with slightly rounded pointed end to pean immediately after welding. With this process, you can take off your glove & lay your hand on the weld area & the cast will be barely luke warm. I let the casting sit for approx. 30min. and repeat the process. Again, you can lay your bare hand on the weld & only feel luke warm. With this process you will not hear the dreaded "tinkle".... a crack. This process works with tremendous success and is how I do all the cast repairs that have come in. You do not have to fool around with pre & post heating that most have no true way to control temperatures. Hope this may give you another consideration to cure your problem with much less effort.DennyComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:could you make a new on out of mild steel with stiffeners underneath?
Reply:it seems like you are on the right track, you might want to shoot castweld a PM or direct him to this thread as he welds cast junk every day and seems to have great success every time.
Reply:There are many ways to weld this that will work. What type of welding are you comfortable with? Do you want to work with a part that is hot (pre heat)? It can be done cold, but will take lots of time. The only thing I disagree with in above posts is welding from one end to other. Start weld from end of crack and weld to mid point then from other end to middle. I usually start on the edge and have good luck. If you answer the above questions I can suggest a procedure that will most likely work.Peter
Reply:Answer to two questions.  I would like to stick weld the lid.  I would be no problem for me to work with it hot. I have the equipment to handle the lid hot.
Reply:Originally Posted by burnandreturnAnswer to two questions.  I would like to stick weld the lid.  I would be no problem for me to work with it hot. I have the equipment to handle the lid hot.
Reply:OK,  I will probably weld it on Tuesday. I will let you know how it goes. Thank you for all the help.
Reply:Get it done???
Reply:Anyone here ever hear Cast Iron crack when you weld it?  I have. It is real loud when it cracks!  My weld cracked down the middle.  I thought I had monitored my temperature correctly but I guess not.  I would crack when I would weld on the other end of the crack.I ground it out a couple of times and tried over.  I burned up $150 dollars of rod and a lot of time. Plan B! Either I build a new lid or use another one I have that will reguire some major modification to the top of the well house.  But now I have to do it,  I have no good cover on my well now.
Reply:Originally Posted by llamafurcould you make a new on out of mild steel with stiffeners underneath?
Reply:What is the lid used for...  Why not just glue it, plenty of adhesives that will work.  Check your autopart store.   Also, did you drill your relief hole at the end of the crack?Put a counter weight on it so nobody else drops it.
Reply:I decided that this lid was going to get fixed and by me.  So I went down to my supplier and bought more nickel rod. Ground out the crack again and this time I heated it up to a highter temp.  I welded maybe three inches and then put the heat back on the lid.  I didn't let the temp drop below 700 degrees.  This time I think it worked.  At least it didn't crack right away or while I was welding it.  So now it is in my smoker and will stay there until tomorrow. It will stay at three hundred degrees until morning. Then I will let it cool off on its own in the smoker.  Thank you for all your suggestions. I will let you know.One other thing.  I used a 2.5 mm rod and it was very difficult to weld with. I had to keep the rod exactly ninety degrees.  The puddle was very strange to manipulate.
Reply:Lid is fixed!  After the cool down I could find no cracks.  It is back on top of my well. Thank you for all the great info.Pics of final repair?HH 187Miller Bluestar1EAHP AlphaTig 200X
Reply:Ya pics would be good. I was thinking maybe drill through it and put a strap on the inside for mechanical fastening or butterfly type like wood joining inside and epoxy... looks like you got it though maybe good luckLincoln 225 Tombstone,Miller Big 20,Hobart 180,150' Argon,A/D hobart hood 22 Ton Log splitter,79 F350 dump eats 4.75 TONS and still turns cutters,grinders,And a  Hypertherm POWERMAX 30
Reply:Glad to hear you got it fixed, cast iron likes lots of heat.Peter