Cast Iron repair, my education!

[Baby Grand]

start with practicing your brazing, i was amazed at how good a joint a properly groved and brazed piece of cast will turn out.

Interesting! I never would have thought to braze cast. I've brazed wrought iron to repair a stairway hand rail and that went very well - lasted 8 years so far. Have to check what filler to use for extended high temperature. Thanks for the suggestion.

 

[john_bud]

The most important thing for you to understand is that electric welding on cast iron is actually the very worst decision you could make to attempt to repair your cracked cast iron part. If you want to make a complete mess of your part, go ahead and arc weld it with nickel rod. Cast iron cannot stretch and withstand the contraction and hardening caused by cast welding with preheating below 1200 deg. F. The brand of welding rod does not make a very big difference. It's the heat that causes the changes to the cast iron itself. Sure the nickel weld is machineable but the cast iron will become as hard as a drill bit or tap and therefore will prevent the proper machining that is often required.

This is from the link. I can tell you from experience, it's 100% correct. Even with some "miracle" rods that were supposed to be able to weld the cast like crazy good. Well... not so much. total waste of time, effort and the end result was cast that was still cracked and weld metal with cast iron on both sides of it, but the cast hardened and cracked on cooling.

Thanks for posting it up!

 

[ptgdigger]

I love the look of the stitched and lock repairs, very interesting site.

Ray

 

[Rodiron]

-Hey john_bud, good morning to you sir and thanks for the section you sent me from the link and what I had to say about repairing cast iron as I said was "my" and mine alone thoughts on the matter. All I was saying is that I agree with the procedure and the correctness of it, but, I'm not going to invest money into somthing that I might use once a year, if that often. I was stating what I do in the moment to repair cast. I would never attempt to repair a piece that needed machined anyway. But I can say this about the Miracle rods, I repaired a one row corn planter 3yrs ago that someone had brazed before and it is still working fine, and the skillet that I mig welded, I am still using. As a 40+yr. pipe welder and retired I really don't give a rats rear of the correct way to repair cast iron, I was just stating what probably 90% of those that post on here already knew, not everything has to be done by the book. Have a great day.

 

[npalen]

Good stuff! I worked for a company back in the 60's by the name of Swick-Guth in McPherson, KS. Their business was welding and remachining large castings ranging from cylinder heads for earthmoving equipment to rear end housings for road graders etc. I was just a machine operator at the time but was very interested in understanding their process. They had no electric heat blankets that I was aware of but used large torches mounted around the casting to apply the heat before, during and after the welding process. Each operator was in a booth that had large fans attempting to keep him/her cool which was next to impossible. Castings along with MOST of their broken pieces would be shipped in from around the world for repair. One of my jobs was drilling out injector port holes in engine heads so that a large cast slug could be welded in and then faced, drilled and tapped. Their were no large fancy machining centers to remachine the large flanges and drill/tap new holes. Most of the machining was done on very large radial heads using Wohlhaupter facing heads. I hope that I'm reporting the facts correctly here as this entry job was nearly fifty years ago.

 

[yomax4]

Boy did I get an education! I thought I had a clue, come to find out I was clue less.
Here are a couple pictures I snagged off his website that I thought were very interesting.

The Pic on the left is Harris Kast-Weld 111. made of cast iron and the flux is optional. It does help on problem castings. It actually works best when you wrap it with copper wire like speaker wire. This puts some of the copper back in the cast that gets burnt out when heating red hot. ( I used to be a Rep for Harris ) The pic on the right is spray powder torch set up. I have posted about them several times. It is still the best repair for cast. Like stated in this thread. When you hit cast with a bazillion volts, It scatters the atoms all over the place causing stress. That's why you peen after welding. With spray powder you only get the cast burgandy hot or a little hotter. After drilling a holes at each end of the crack you can quickly do the repair.. I have fixed Corvette engine blocks hundreds of manifolds and joined antique tractor brake and clutch pedals. Now if you get into 2-3" cast you will want to choose a different method such as Kast-Weld 111 or stick welding with Ni rod. I like the synthetic nickel rods better than the actual 55-65-99% etc. Brazing will fix some cast jobs but it expands and contracts at a different rate than the cast and will often let go over time if heat is an issue. The Spray Powder torch in the above pic looks like a Eutectic brand and costs about $1200.00. You can get one from Victor with powder for $380.00 and is very durable. Another application for the powder is hard surfacing. Stoody offeres a dozen recipes with varying amounts of carbide. You can put it on thick or thin. Spray the back side of your lawn mower blades and they remain sharp forever or until you hit a rock. lots of cool products out there and they make repairs enjoyable.

 

[Shield Arc]

The Pic on the left is Harris Kast-Weld 111.

Yomax4 do you have any on line sources to purchase cast welding rod like in the picture on the left.
George recommended this site, but it's been down for a week or so.
http://www.tuckervalveseat.com/


This is the only site I've found so far, but I can't figure out if that price is for 1-pound, or how much.
TM Technologies - Cast Iron Flux and Filler Metals

 

[Bladehauler]

Shield arc,
Tm technologies is for 1 pound, ( I just clicked add to cart and it showed 1 pound )

Good Luck

 

[yomax4]

When Lincoln Electric Bought JW Harris, They discontinued many specialty products and 111 was one of them. If you call Airgas, Praxair, Matheson etc. I bet they have some on the shelf yet. I mention these 3 only because they have large networks and can look on the computer to see if anyone in the country has it. Matheson ( Linweld ) in Omaha used to stock 2-300# at all times.
Also, I sent a note to the Harris buyer who is an old friend and he will send me the manufactures name who he said will sell to anyone. More later.

 

[CDN Farm Boy]

Cast Iron or Cast Steel? Is there a difference in the welding/machining process?

From my limited understanding, they are quite different materials but often the name is used interchangeably. How do you tell them apart?