Nickel Rod Ni55- What's the trick?

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I am having trouble with some Ni99 Stick.  I can't find the amp specs and I want to do a little practice with it cause I have some jobs coming up that call for it.  I need to make the welds look nice not just stick.  I am going to weld 1" A36 to 1" Cast Iron. I did one before in an emergency and My welds looked like crap.The tensile strength of the weld didn't matter.  I knew it was crap and I told the customer it was crap and they still loved it...BUT...I would like for the next time I go do this job again I look like a pro.So...Here is what I know.-I preheated the material (both pieces).-The rod (suposedly) was AC or DC(+) and I tried it in both.  (This is what the LWS told me.  They had to blow the dust off the already opened box since this was all they had.  So there was no amperage info.)Currently I am trying to practice on 1/4 in. A36 preheated and at room temp and it makes no difference.  My welds just look horrible.  I'm not bragging but I do have my AWS D1.1 Cert so I do know how to lay a bead good enough to pass but this nickel rod looks bad.I am wondering if the rod could be old or defective or if the heat is way off.  I have tried various heat settings but finally had to stop and ask because this rod is SOO expensive. I have tried dragging the rod, pushing, short and long arc but the slag just seems to mix in with the weld like ash.  I feel like the weld isnt penetrating. It looks like when you are welding GMAW and large gust of wind blows it, porious and tall and bubbley.   Is maybe the point to the design of this rod to make a bead that mimics Cast Irons' physical makeup?Am I not letting it cool enough before cleaning the slag?What Amperage should I run?By the way the rod is 1/8 and I am using a Miller Dynasty 200 DX (just to lay out all the variables I can think of.)And while we are on the subject of this "Exotic" rod (judging by the price).  What else is this rod good for? i.e..gold to silver...or...aluminum to copper...or...stainless to steel...?I had to buy 10 pounds and it was supposed to cost around $300 although the charged me less, nonetheless.
Reply:I wrote in the begining of the opening of this thread Ni99but it is in fact Ni55.
Reply:All-State makes a 55% Nickel-Iron rod called No. 8-60 which is for heavy sections of cast iron or ductile iron. 1/8" rod uses 80-120 amp. on AC or DC Reverse. Recommended preheat is 600*F.I once tried using some old nickel rod and kept having globs melt off without getting a good, continuous arc. Turning the current up didn't do anything except give me globs faster, so I assumed the rod coating, which looked close to falling off, was the cause. I think I ended up using the rod for gas welding later, but that was long ago, and I'm not sure.....Nickel rod is expensive due to the nickel content, and because much less is used than 7018 or 6013,  they probably charge more just for handling it.BTW & FWIW,  I think mine was 99% NiLast edited by Oldiron2; 10-30-2008 at 01:15 AM.
Reply:Nickel alloys will not bond to the cast unless you are very clean meaning no traces of dirt or burned oil.  The weld bead should appear relatively cold.  You are not looking to burn it into the casting.  The 55 should fuse more easily that the 99.  My age is showing but last time I bought it was ten a pound.  I find it hard to believe it has gone up three times that.
Reply:If you're welding on steel and are getting a ton of porosity and having issues that severe, odds are the flux on the rod has been contaminated or dried out so severely from age that its no longer any good.  Make them take it back, and if they don't believe you, tell them to run a bead with it.
Reply:You are using the wrong process.http://www.locknstitch.com/CastIronWelding.htm
Reply:Kepe- here is some advice for you.WHen you see a long article contrasting the pros and cons of one product versus another, take it with a grian of salt when the article has been written by a vendor attempting to sell you on of those products. Whilere there is some valid advice there, welding cast to steel using nickel rod is a perfectly acceptable process and is done every day. As has been said, nickel rod tends to look cold, the puddle is "thick" and not very fluid. As was also said, if you haven't yet, try running a bead on a piece of clean steel- if you still have porosity issues the rod is junk. if it's good then you need to clean the cast more (grind the weld area well with a clean carbide burr. If you have access to TIG I would chip the flux off, clean the rods with a scotchbrite pad, and tig it- again at 80-120 amps or so. I do that all of the time with NI99 and it works great.
Reply:Originally Posted by kepeYou are using the wrong process.http://www.locknstitch.com/CastIronWelding.htm
Reply:Lockstitch also welds cast and discusses the proper way to do it. I only gave the link so he could read up on proper cast welding techniques. I have welded cast more times than I would have like to have done and I will never be a proponent of arc welding cast...it's just not a proper process for cast. My $.02.Captbondo, sorry but I stand by my posting because I have welded cast iron for over 30 years.....I firmly believe in how they do the work and the documentation they give on the subject because that is how I have done it for years, so instead of trying to type it all here, I give the link.
Reply:Originally Posted by kepeLockstitch also welds cast and discusses the proper way to do it. I only gave the link so he could read up on proper cast welding techniques....
Reply:Originally Posted by kepeCaptbondo, sorry but I stand by my posting because I have welded cast iron for over 30 years.....I firmly believe in how they do the work and the documentation they give on the subject because that is how I have done it for years, so instead of trying to type it all here, I give the link.
Reply:I find stick goes on fine if the piece is hot enough,  Then you need a lot less amps the the rod flows quite well.   Like 80 amps for 1/8".  I have never pinned a block or saw anyone do it, so I can't say......Brazing or Tig with ni99 (electrodes with the flux cleaned off)  is a nice way to go. You have to preheat and cool slowly no matter what process you use.I have cold welded a couple of tractor blocks.  It works, but .......David Real world weldin.  When I grow up I want to be a tig weldor.
Reply:One aid to a good hold is to put stainless threaded pins (such as 304) into the CI first. The NiRod will weld well to the pins, and they will help distribute the tensile stresses below the surface, reducing the risk of separation in service. How many, how deep,  and how close together the pins should be depends on the details of the job. The pins should be threaded in and cut off just proud of the surface. Takes time to drill and tap the holes for the pins, but is well worth it. The pins I have used are #10 machine screw thread.
Reply:Originally Posted by denrepI couldn't find the page.How about a link to their cast welding web page? They've done some impressive repairs, maybe we can learn some cast welding tricks from ‘em.
Reply:I've read Lockstitch information I'd gotten from Industrial shows, and it looks as if it would be great for some applications, just not any I've had. I broke the handle on an old Champion Blower & Forge Co. Post Drill long ago, and wanted it to be original when I was done. I welded it, and actually sand blasted it with huge grit when done to make the surface match the rest of the part, which was a sand casting.BTW, MG (now a Div. of Messer) has information in its catalogs about welding cast iron, which says "Knowledge gained in the oscillation technique field--the investigation of fatigue  resistance at dynamic stress-- shows that studding is outdated." The studs can actually act as stress raisers.
Reply:Originally Posted by CapnbondoThat's fine, state your opinion as your opinion, not as a hard fact that he's "using the wrong process". 30 years or not, plenty of people have been doing it that long with the "wrong process" as well without issue.  Now I guess i have to apologize, becuase I find it hard to believe that all of the nickel stick rods formulated specifically for cast, that have been produced in large quantities for years, are some big conspiracy and they don't actually work when used correctly just becuase you say so.Especially since I use them a lot and they work fine.
Reply:Just my .02 worth, I recently had to repair two cast iron plates we use to stabilize sheet metal during heat treatment.  They are 3 inches thick, and due to the 5000# load applied, the eventually cracked through the full section.  Double V-groove from both sides leaving a 3/32 web through the center of the part, preheat with O/A to take the chill off the plate, and then start laying down 1/8" Ni-99 rod as fast as I could.  Parts were then machined flush, and back into service at 5000# load, with no cracking issues.  Cast, as a result of it's morphology, is inherently less prone to issues from thermal stress.  That's why it's the material of choice for heat treat tooling.I too have been arc welding cast iron for 30+ years, and I have never found it necessary to preheat it to 1000 degrees, or bury it in dolomite for 48 hours to allow it to cool off slowly.On some parts with varying cross section, I may take the preheat up to nearer to 400 degrees....Arc is a proper way to weld cast.  And yes, I r 2 a perfessional....Just my .02  I r 2 a perfessional
Reply:As I understand the theory,When nickel rod is used, the arc melts some of the iron. Some of the carbon from the iron dissolves in the molten nickel of the now nickel-iron mix. Carbon from the boundary layer may even dissolve in the mix,  lessening that iron's carbon content.The carbon concentration of the mix is now less than for the parent iron, and, as the high-nickel mix cools, most of the carbon separates as graphite again, giving a shrinkage rate of the mix which is about the same as the parent iron boundary layer. If multiple layers are used, the reheating of the boundary iron layer will allow the dissolved carbon to redeposit as graphite, reducing the brittle cementite significantly. Thus, correct welding of cast iron involves both good material and using the proper procedure. The fine details of the procedure MG recommends are supposed to be available from them.BTW,  getting 'constantly older' is not 'the proper way to live', but until someone finds a better way, it's better than the alternative.  Even if cloning ever is possible,  that will only involve the body, not the spirit. Not quite the same as with old engines or drills, where recasting missing parts or making copies of entire machines is possible.