When welding cast iron, the filler metal is usually an alloy of mostly (90+ percent)
nickel and other stuff. Lots of people use Ni99 filler others use NiCu7 and there are others.

I am not familiar with what you have, what alloy is it?

 

Burnit,
Actually you are right and wrong. The mostly nickel rods came out as a cheap easy way to "braze" cast iron, its not a true fusion weld. Fusion welding using a filler material of cast iron with a few percent silicon in it is traditional and still considered the professional and produces a result of the highest quality. Cast iron manifolds and blocks/heads for high end vintage car restorations, as well as industrial diesel engine castings are quite often fusion welded where the questionable repair done with an electric arc cant be tolerated.The nickel rods are popular with the Ag crowd, and other areas where diasassembly is impractical. Bronze welding can often be used in the same situations, without the same thermal shock as the arc can cause. Thermal spray welding (brazing) of cast iron is also popular, and is generally a higher quality repair vs. the arc. even though similiar alloys are used.

The Traditional cast iron fillers are sold by Harris as KastWeld 111, and by Aufhauser as "Cast Iron Rod" , Both companies offer matching fluxes. These are the fillers for the OA process that has been used for over 100 years.

 

Don't have a clue.... 3/4# loose rods...... I thought it was solid CI rod like those used with a Henrob torch to weld CI. I was given a Henrob torch a few weeks ago and the film of the CI manifold repair interested me the most.

I live in farm country & tractors and misc. motorized equipment always seems to be cracking manifolds. I've had others "attempt" to fix mine in the past with sorry results. At the time I didn't think their methods were correct,but after doing research I'm positive they were shine-in' me on about knowing what they were doing.

Once you are aware of correct methods of doing anything it becomes really hard to swallow BS about repairs to your stuff... $150 hard to swallow for the last tractor manifold I had to replace when the "do-fus" layed a huge Ni bead on a cold manifold with added melted holes in it.

I really believe that old saying..."If you want it done right...Do it yourself" Now more than ever.

I think this alloy rod would be fine to repair some CI applications..perhaps any that might require machining afterwards...it seems like a soft alloy(like pewter almost) with a galvanized like coating on the rods. I hope the seller can/will give more in depth info on it's qualities/usage.

I really didn't expect to have trouble finding info on it....I usually just look it up and bingo...there it is,but like I say...It wasn't what I thought it was.

Thanks,Dave

 

Makoman,

I respectfully beg to differ, Lincoln's NI99 rods are in fact welding rods, and do produce fusion with the base metal. We have large cast iron tooling plates that often get overtightened, and crack through 2" thick. We bevel out the crack from both sides, leaving about a 3/32 web, break out the buzzbox, and go to town. Preheating is not necessary. I understand the OA process has been around a lot longer than the electric arc, but it doesn't negate the ability to produce a weld, not a brazement, with the NI99 rods.

FYI, when we need to do a quick TIG weld, we knock the flux off the rods, give them a quick lick with some sandpaper, and they work fine for that, too. It's the one rod I always make sure I have at least one pound of in my toolbox.

Best regards, Kbnit

 

Kbnit,
I know where your coming from, and it depends on the alloy of the Iron but consider this:
-Gray Iron ( typical automotive grade) has in the neighborhood of .5-10% Nickel
-Melting Temperature is about 2800-3200 F depending on the alloy
-Nickel 99 (basicly pure nickel) filler melts at about 2642 F
-We use that same almost pure nickel, in powder fluxed form, for thermal spray work, it fuses to the base metal without melting the base cast iron.

Technicly, true welding uses a filler metal of near identical, or identical components as the base material, so you can see if you looked as the cross section of the finished "weld", you would go from Iron based, to almost pure nickel, and back to Iron based. I know its done, but I still dont like the thermal shock of electric welding on Cast Iron, reguardless of filler material. In a similiar point, think of it this way, using 4043, or 4047 filler on 6061 aluminum.....is actually brazing. With the torch you can control the temperature so well you can literally "sweat" 6061 parts together without melting them, using 4043 or 4047 filler. Electric welding blasts the 2 together. I think thsts maybe where the confusion comes in, most of these materials were developed in the torch days....where you could control the heat well enough to actually braze material soo close in melting temp, now with electric welding, you lose that control, so everything melts together, and its thought of as a fusion weld.

 

If you melt the 'parent' materials, it's a weld.

If your filler metal melts above 840F but you don't melt the parent metal, it is brazing.

If your filler metal below 840F and you don't melt the parent metal, it is soldering.

Depending on the specific filler(s) and parent material(s), you could solder or braze or weld the same/similar materials.

So a lot depends on exactly how you get all the different metals to dance together.

Arc welding cast iron using a nickel rod is welding. The arc is hot enough to melt the parent materials (cast iron) and also deposit molten nickel alloy. The molten mix then cools and solidifies.

If you use a heat source to get the cast iron hot enough hot melt the nickel but not melt the cast iron, then you would be brazing. (temperature above 840F but not melting the parent materials)

etc, etc

Yup, taking some aluminum with a higher melting point and some filler with a lower melting point (but above 840F), and carefully heating things so the filler melts but the parent aluminum doesn't and you are brazing the aluminum together. Get things hotter and melt the filler -and- the parent aluminum, and you are welding.

As to the OP mudbugone, product names don't always tell the whole story by themselves. A data sheet, or the AWS classification, will tell you more. A data sheet and a property sheet and a usage/parameter sheet tells more.

I have no idea what the particular rods you have are.

 

As to the OP mudbugone, product names don't always tell the whole story by themselves. A data sheet, or the AWS classification, will tell you more. A data sheet and a property sheet and a usage/parameter sheet tells more.

I have no idea what the particular rods you have are.

These are points I'm finding out--I was thinking someone here might be familiar with the brand rod if not it's composition....I'm still trying to get a response from the seller on them.

I went back to the original listing & it states "Cast Iron Rods" but goes on to say in the description they are an alloy & have a low melting point to fill cracks in Cast Iron. That wording leads me to think these are for non-structural cosmetic sealing of CI cracks rather than welding CI in any form. I read into the listing what I thought I saw listed,but obviously just didn't study the description close enough to understand the rods themselves were not cast iron.

I appreciate the help and Please continue the conversation on the different processes--- If I can't learn one thing at least I can learn other things with the discussions--- I'm enjoying the knowledge and I'm sure others will as well.

Thanks,Dave

 

As I understand things, when the nickel rod's arc melts some of the cast iron, the carbon goes into solution in the high-nickel alloy but again precipitates as the alloy cools. This decreases the shrinkage so that fewer stresses are set up, and the alloy is also more malleable so will deform somewhat to relieve those that are.
As such, I would agree that this is a true weld, not brazing. My opinion is based on reading books and catalogs, not AWS definitions or specs., and as I see it, it's really a matter of semantics here. Nobody is arguing basic facts.

I was just looking through the current Technical Data Book for Castolin Eutectic and don't find any rod called #15. It does show a #157 rod which has a high tin content and some silver and melts at 430*F (both solidus and liquidus). Its shear strength is 15K psi.
It is "suitable for stainless steel assemblies, brass and bronze components, nickel alloys and most carbon steels when used with Eutectic flux #157. "
Their #141 is for fusion welding cast iron as mentioned by Makoman 1860 above.

 

I've had the best luck repairing cracked exhaust manifolds by brazing them with O/A and never had one bust. I have repaired a great many that others had tried to repair using stick electrodes.

Don't count out the brazing process strength wise for cast iron repairs. I have used brazing alloys that had 110,000 psi tensile strength. It is used frequently in the oilfield for repairing busted and cracked bearing and gearbox housings. I have used it on castings so big I had to use a #12 Victor rosebud to get it hot enough and keep it there for brazing. I've brazed broken off flange corners on gearboxes up to 650s (they attach using the flange) A 650 means it generates 650 tons per foot of torque that's 1,300,000 ft/lbs of torque. Healthy loading by anyones standards. My experience has been that about 90% of a good cast iron repair is proper preparation. Without that it doesn't matter what process you use it won't be a sound repair. It isn't such a problem on modern castings but the older the casting is the more difficult they can be to be repaired. Some of them can't be repaired. They just will not take metal.

I didn't find anything at Castolin Eutectic's website concerning anything called 15. There is a 16 and an 18 brazing alloy.

The only actual cast iron filler I have ever used was for tig. I do not know what it was or the composition. I was handed one by my boss and told to do it. It looked and felt like gray cast iron. It formed a puddle very similar to mild steel and looked very similar to a tig weld on mild steel when finished and was readily machineable. It was a cracked out bolt boss on a pump housing that had to be drilled, tapped and resurfaced for a gasket seal when I was done. We worked with a lot of stuff that wasn't the norm for the area in that shop such as Monel, Inconel, Titanium, and lot's of cast iron. Great place to work and very interesting as long as you didn't mind starving.

I use Allstate's Corecast 8600 gas shielded flux core wire for joining cast iron to steel as well as repairing antique (100+ years) iron castings. The .045 needs about 200 amps to burn and is strictly spray transfer. It was over 40 bucks a pound last January and I have no idea how high it is now. The smallest spool I have found is 10lbs so there is no cheap way of using it, lol. I've never tried it on exhaust manifolds, but brazing is so much cheaper and I know how well it works. My business partners brother (industrial machinist) has been using it for 20 years for building up crankshafts for industrial engines and natural gas compressor shafts.

I have never seen a filler for the actual welding of cast iron using O/A.

 

JR,
Harris Kastweld 111, and Aufhauser "Cast Iron Rod" are both OA filler rods for fusion welding. Ill give you guys a little hint, parts of the issue with a nickel "weld" in cast iron, is the difference in thermal expansion between the 2 materials if used in a hot environment. I have seen manu exhaust manifolds that we make, repaired by the ni99 rods, they look and work fine....for a while...but eventually stresses and corrosion cracks start forming alongside the "weld". On water cooled manifolds its not much of an issue, but on air cooled ones...different story. From a metalurgists point of view....not a good thing. And actually using the OA process is quite easy, and the results are really nice....give it a try!

 

I should have known if I bought it..it'd be unusual and hard to ID.

Here's the listing which may help somewhat and may give a better idea of the material...
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180276107853&ssPageName=ADEM:XRTQ:US:1123

Thanks to everyone for the input.

 

I will post pics tomorrow, but I just welded up a bunch of cracks in a cast iron manifold using NI99. I definitely melted the base metal- I ran 1" at a time, waiting until it was cool to the touch before welding another 1". Did not try to crack when cooling AT ALL. I'm super happy with the results!!!!

I'd braze a manifold for a normally aspirated engine but this is a turbo manifold so I was worried about the temps.

 

I used pure cast iron rods with a red flux you dip em into and OA. It works, but I preheat the whole thing first. When using brazing rod, I have to be sure NOT to melt the cast (base metal) or it won't stick.

David

 

I used pure cast iron rods with a red flux you dip em into and OA.
David

That's what I was going for since they were listed as 'cast iron rods' I wanted to practice using a Henrob torch ---the welds looked better in the DHC 2000 videos than any CI repair I've seen done.

 

Thanks makoman. I am going to make a note of those and put them in my book. When it comes to cast iron you can never have enough alternatives.

That's why I use brazing on CI exhaust manifolds. Every one of the ones I have repaired where nickel based electrodes were used failed because it cracked out. I think the corecast might actually work well for it, but as I said it's pretty expensive to play around with and I already know brazing works well at least for me.