Another broken casting....

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Hey guys,Here's a job that came in from a customer because a woman who was yadda...yadda...yadda on her cell phone was not paying attention to driving. Luckily for my customer, the lady stopped & informed him she ran into his mailbox post & broke it & offered to pay for the damages. Talk about luck....When he brought it in, he indicated he slightly ground off the paint about a 1/2" on each side to see if there was any elongated cracking. It was a clean break. I wire-wheeled the surface to clean the slight surface rust & put a .045 bevel around the edge. For all the casting repairs I do, I use the Cold Welding Cast w/MIG process that has been 100% successful so far. When I set the (2) pieces together, the match was perfect & I put (4) magnets to hold it while I tacked a spot on each side to hold. I used .030, 309L, 98/2(AR-CO2) at 80A & ran a 1" bead on opposite sides & after removing my gloves, the casting wasn't even luke warm. I allowed 15 min. & did the next (2) 1" welds on opposite sides again and repeated the process until finished. The casting never got more than luke warm & there was NO TINKLING....the dreaded sound of a crack. Anyway, here's some pics & hope this may help someone.Denny Attached ImagesComplete 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:Is their a question? Kinda looks like it never got luke warm. Did the weld get any penetration?  But..........if the customer is happy....Or as zapster says, "The difference between an average person and a true professional is that the true professional will do a really good job..even if they don't want to..OR have to""SOUTHPAW" A wise person learns from another persons mistakes;A smart person learns from their own mistakes;But, a stupid person.............never learns.
Reply:Denny,Isn't 98-2 usually argon-oxygen?  I don't recall ever seing C2 as a gas mix option at the LWS.  C5, maybe.  C15, maybe.  C25, sure.Unless you are running your own gas mixer?  But, yup, cast iron can be welded HOT or you can try keeping it cold.  Your keeping it cold seems to have worked.  What, no NI55 stick?    The best laid schemes ... Gang oft agley ...
Reply:Hey MoonRise,I get my 98/2(AR/CO2) mix at my local Airgas & just keep a 40CF bottle as I use it only for the SS/cast repairs I do. The Cold Welding Cast w/MIG process is apparently widely misunderstood. The are numerous publications & other forum posts regarding the process. I researched everything I could find for several months & experimented several months until I reached very successful repairs. If you are somewhat experienced with some years welding, I'm sure you have heard the term that MIG welding is called "cool welding" because of the applied arc with wire & the lower overall heat dissipated.Research indicated that 309L SS wire was optimum because of the low carbon content of .01 & would not cause issues with cast. Also, research on Ed Craig's Weld Reality site confirmed 98/2 to be optimum for gas coverage using 309L.http://www.weldreality.com/MIG_welding_gases.htmMy technique is to lightly grind 1/2" on each side to bare, clean the weld joint surfaces & just wipe any potential grease or contaminant with acetone. Depending on the thickness, I bevel both sides, generally from .045 to .060 at a 45* angle. This gives me a .090-.120 "V" groove to run a root pass & I use .030 wire. If the joint is separated as this job was, I just apply (4) small tacks at 90* to maintain concentricity of the piece. Then I start my 1" bead inside the groove enough to fill the groove with the MIG gun almost 90* for penetration. I then lightly pean the weld with my slightly rounded slag hammer point. I then rotate 180* & do the same on the opposite side. After each 1" bead, you can remove your glove & the casting will be barely warm. I allow 15-30 min, depending on the size of the casting to return to room temperature. I repeat the process until the entire joint is welded. This bead is only .100-.125 in width depending on groove width. When finished, I allow to sit (2) hours & then do a cover pass the same way.... 1" at a time, alternating sides. This is to strengthen the joint & will allow grinding some excess to dress off the welded area if required by the customer for aesthetics. Small repairs & thin castings that only need cracks filled only require (1) pass. With some of the cast iron stoves I have done, I have grooved both sides & welded both. I do purge cylindrical applications.Concentrating on the initial arc of the wire & the puddle forming will reveal how nicely the SS wire adheres to the cast. I use the "pull" technique for all the cast welding I do which does render better penetration.Over the years, I have used silver-solder, brazing, Ni55, Ni99, sil-bronze TIG,  pre-heat, post-heat, oven cooling, & sand cooling. I found trying to control heating & cooling to eliminate or reduce cracking is next to impossible unless you have the equipment that utilizes computer-controlled temperature variances. There are companies that do this....and believe me, quite expensive. For the repairs I do, this process has yielded 100% success & I will stay with it.Member here, Dave Powelson, also uses this process with success & can supplement some of his techniques.As far as papabear's reply: You need to clarify: "Is there a question?". How would you know if  "it looks like it never got luke warm". As far as Zap's response, I would agree & I can only surmise you projected your innuendo that this was not a professional job.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."