Welding Cast Iron

FWIW I have never tried but I have seen a 7018 rod used on cast with good results.
 
I am a novice, but have brazed some cast iron successfully. I had a little Jet 1018 woodworking lathe that got pulled off the table last year and the base broke in half. Brazed it with oxy/acetylene and whatever Hobart bronze rod and Hobart brazing flux from Tractor Supply. I believe I pre-heated the parts very slowly and conservatively and burned a lot of extra acetylene in the process! But the brazing worked great and the repair has held.
 
Like some have said Preheat Braze and slow cool .I have used Kitty litter to bury parts in and cooled them that way.
 
braze em' up, you'll be glad you did.
tig is great, but you'll need lots of patience, gas and time if the repairs are going to be extensive.
you can set up and braze it in a very short time.
if you are anything like me, the tig repair process will take exponentially longer to complete.
good luck either road you decide to travel.:)
 
+1 on brino's BBQ grill approach. I used that method when I repaired a cracked coal stove chimney manifold a few years ago. I was pre and post heating with a torch and stick welding it, just like others have said I used short welds and peened it well but it kept cracking. I had welded cast successfully before without too much trouble but that part was real nightmare. As a last attempt, I tossed a bag of charcoal in the Webber grill, fired it up, got the part pre heated and welded all the cracks, put the lid on, closed the air vents and let die out. Part cooled without cracking and is still in use. I don't remember the rod I used but it was bought from McMaster Carr, recommend for cast iron.
 
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The air hammer might be a little to much, but the needle de-scaler might work well. Have always just used a frantic chipping hammer, but if you did a lot of it a shot-peening cabinet would be great for most stuff. Mike
 
I guess you will be the first one here to try it. Apparently that stuff is an internally fluxed blend and has been around for many many years( if we believe what we read on some very unfriendly forums). It looked like it worked for Mr. Tig in the video. Based on searches I have done I think this is the rod http://eureka-china-jining-kaitai.com/upload/products/66/66_20107261444.pdf

I say try the EZ weld filler and let us know. With farm equipment in the family I have the "opportunity" to weld cast fairly regularly and would welcome skipping the pre/post heat hassle.
 
like i stated before i have welded cast iron for 20 years and they say pre heat it but i can count on 1 hand how many times i have done it. Gouge it out real well with a bur, use a small er rod for the root pass, only short wolds let it cool weld some more, follow up on the next pass with a larger rod, (99% nickle) not ni rod. Put it in lime or sand to cool. If it is a crack you are welding drill the end of the crack so it won't run further and last of all fill the drilled holes. There is nothing wrong with brazing i have done both just prefer ark.
 
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