I've Brazed Cast Iron, successfully. The handle to raise and lower the table on a Bridgeport style milling machine is easily broken when moving stuff. Used a Cutting Torch, to create lots of heat, so it would cool slowly. Bevel the edges to ensure penetration. Done a couple, no problem.
Von Rigg Fink is right You can weld cast iron You need to preheat.An oven works good for this. Plus boils out contaminates .Around 450 pull out hot and weld let cool.
Yes, cast iron can be welded to steel. It can also be brazed but I prefer welding. Like others have said, PREHEAT and POSTHEAT. Acetylene is a good easy way to preheat. A nickel rod makes a good weld, also certanium. Go slow and always keep it warm. After welding for post heat I have thrown the part in the wood stove. I have also put the part in a steel bucket and filled it with embers or coals from a wood fire. A two day cool down would not be too fast. My first hotrod was a '54 Ford Skyliner with a 302 chevy engine. I had home made fenderwell headers where I welded 2 1/2" steel pipe to ramhorn manifolds. I have a picture of the car on my website but no closeups of the exhausts, dammit.
http://www.lincolnelectric.com/knowledge/articles/content/castironpreheat.asp These guys should know what they are talking about.
[QI have heard that story many times and have fixed several Mopar moter home manifolds and never had a comeback after years. One doubter even bought another set for when it broke. About 5 years later he came into the shop curseing me for makeing me wast a few hundred $$ by buying a set of manifolds he never needed. He gave them to me. Pre heat- post heat good Nickle rod and clean and the com back rate may be 10%. GEORGE!! UOTE=kustomizingkid;4450636]Like I said I put every cast iron anything weld at a 90% failure rate... it will hold together for a while... but most stuff eventually breaks, just have to hope if it breaks that it is easy to get to and reweld That method has gotten me the BEST results out of any method...[/QUOTE]
I've had a lot of success welding cast iron in the past. I have an oven in the shop for preheating things. I usually go to 400 degrees or so, and make sure its very clean. Exhaust manifolds have always been difficult because they are dirty inside and out. I've used hot solvent to wash them out as best I could. I've had better luck cleaning it with 40 grit sand paper, files, steel wool, carbide bits, and stainless wire brushes. When welding cast to cast I use N99 or N55 rod. Whenever I stop welding I "ping" the end of the weld, which is essentially tapping it with a hammer as it cools. I've never been sure on how effective this is too prevent cracks at the weld, but it was a tip handed down to me by an old time welding instructor. When joining cast iron to a dissimilar material, I use the same methods above with a Stainless 312 filler. It's expensive, but it has a higher nickel content and a higher tensile strength. I've had decent luck with it. None of the cast to cast jobs have broken, and the cast to dissimilar are probably 75% success. I would still lean towards a pair of headers. It will probably be less of a headache in the future.
Dude its done all the time... The guys that say it cant be done have never done it and their a bunch of sheeple following the m***es I have a rockcrawling background and have seen countless applications of linked tabs on D-60s running 40plus tires getting full throttle via LS1's and it;'s all good. I recently did a D60, 4 link coilover swap on my D-max using a 79 ford F350 D60 front and I had to weld a link tab to the PIG. heres what you do - hit the cast with some torch heat ( not cherry red ) - stick weld it using DC reverse polarity high heat 1/8 rod - Ni-99 rod ( spendy but worth it ) - s***ch weld at about 2" lengths - throw your wleding jacket over the area for 10 mintues repeat Heh, this process has held up on my 8,000 lb DMAX so to the haters
Yupp ,thier all right,I fix,mix andweld cast iron all the time ,and the new Ni rod will weld without pre heating to most cast iron under 1/4" thickness,Ive mig welded cast iron and sealed it with good old fashion silver solder to make it air and water tight. and drop the cast iron piece in hot sand and let it cool slow. and brazing will work too thats what the old timers used on early indy car front suspenson components.
Hit the wall at Arlington (Minnesota) race track about 8 years ago and broke the motor mount "ears" off of one side of the hemi in my avatar. I'm not much of a welder, so I took it to a friend of mine who is a union pipefitter for a sprinkler company and a real welding freak. I found 2 of the three ears that had broken off on the track after the race, but the third was lost. He went out into the field behind his house with a big hammer, found what he liked on a piece of junk farm equipment, hit it just right, and had the third "ear". I had to do all the "hard" work, which consisted of slowly preheating the block and "ears" with a torch (it took about half an hour). He ground bevels on the ears and welded them on using an arc welder and nickel rod. I then got to hold the torch on and about the welds for about another half hour (it seemed like a lot longer than that). End result? It worked great, I've probably run 20 races on it on some pretty rough tracks, and everything looks real good. That motor mount is one of he first things I check before I run. In my book, if you get someone who realy knows what they're doing, no problem.
I MIG welded up several split manifolds for straight 6's . I have even cut some rams horns SBC manifolds down so the ex . didn't drag the ground or look ****py from under the car. Keep it super clean- muratic acid works wonders. Preheating is also needed. Cool slowly after the fact .I have never had one fail
This question's about as loaded as "which brand carburetor is the best?". I have both brazed and arc welded cast iron with no problems. Yes, the cleaner the better for both methods, and I wouldn't even attempt to arc weld it without high nickel rod.
I have a old vette motor that has a weld and looks like its been there for a very long time not really sure why its welded but it looks like it has held up
I use a new rod for dirty cast iron. I get it from my Miller dealer but i am not sure who makes it. It comes in a blue square tube and has appaently some copper in it. It works very well. It is machinable and almost undetectable when welded. It isnt cheap but that seems to be not important since it works. Don
Pre heat in an oven for a few hours ,Brazing is the simplest .I n my opinion .Vonn rig Fink is right nickel rod and preheat ......
I welded a cracked (cast Iron) steering box All I did was groove out the crack and used a Nicle rod with black flux coating and stick welded it. just let air cool. lasted for years.
The Jalopy Journal
