Cast Iron welding

I've got large cast iron part that has been cracked and needs to be welded, I know that welding cast is dicey at best but it's a job that has to be done.

I've been doing a lot of reading and many sources suggest using nickel rod and very careful pre and post welding heating.

I also came across This Website that promises not only to end all my cast iron welding troubles forever, but to eliminate the need for a slow cool down period. My first impression that this miracle rod is just some more of the welding snake oil one sees every day, so I'm wondering if anyone has experience with it.

I've got at my disposal MIG and TIG and Stick welders and an oxyacetylene setup and I'm pretty proficient at using any of them. What is your advice on the best way to weld cast iron?

 

Use the nickle rod with the arc welder. It will work fine. I have had good luck and have never pre or post heated just let cool slowly don't quench

 

The Henrob does a great job. It is quick and it is easy.

 

I've tried their rods for pot metal. I had no luck at all and I sent them an email saying so. Mike Muggy wrote back and asked me to send him the part (my badly broken grill) and he'd give it a shot. I did. He did and then sent it back. Of course he only joined it in one place to prove the rods worked. The 2 pieces were solidly joined. Unfortunately he did the repair on the exterior surface and when ground down smooth it fell apart. I tried many times afterward to get the stuff to fill notched joints to no avail. I never was able to find anyone to repair that grill.

 

I,ve successfully welded a couple of cracked blocks using nickel rod.
Both were out of the car so I was able to pre-heat them by pointing a salamander heater a few feet away and warming the blocks for about 20 minutes.
Cracks were cleaned and I vee'd them slightly with a carbide in my die grinder.
Welded about 1" at a time and lightly peened each weld until it was cool enough to touch,then continued on.
After I finished welding I covered the blocks with sheetmetal and old canvas to hold in the heat and slow down the cooling.
Both motors are still in use,never leaked a drop.

 

i have done a lot of cast iron welding over the last 25 years. and as mentioned the nickel rod and stick welder is the way to go.

you didnt mention what the part is so:

1. if it has had oil around it you will need to heat the part to boil out the oil, or alternatively , weld and then grind it out again as the oil will leave lots of pits, and holes.

2. if is is a clean piece then oil may not be a problem.

3. also if it is something with differing thickness's stress may be a problem.

4. if it is thin section it may pose differing set of problems.

would help to know what the part is, and where it is broken.
let us know and i can lend some advice.

i have welded succesfully freeze cracked heads and blocks, manifolds, and bell housings along with assorted winch cases gear teeth, sprockets, etc. all of which have differing setup and concerns for a good and effective repair.

whatcha got there?

bob g
ps. been about a year since i have been on here, hopefully a new intro is not in order, but if so let me know and i will comply .... before germ kicks my ass

 

It is a bellhousing from a old 1973? crane.Thanks

 

hmmmm a bellhousing.. k?

maybe a bit more specifics are in order, where is it broken?
is it missing a bolt ear? or does it have a crack? missing any pieces, one crack or several? and how big a crack, how long etc...

trying to help

bob g

 

if it is a small crack you won't have any problems welding it, if it is a long crack it becomes a bit more of a problem.

clean it well, vee it out, and use 1/8" nickel rod, at around 115 amps or so.

the idea is to weld in short stitches, and use a chisel point chipping hammer to pean the weld.

i usually dont weld over about a half inch at a time, and pean cross wise to the crack to relieve stress in the weld area, pean it well, dont have to beat it to death but you want it well worked out with moderate hits. then weld another half inch and pean again.

dont get the piece too hot, if you do as i suggest and pean well the metal wont get much hotter than you can touch.

if you see any pin holes or blow holes, just continue the welding process and when done grind the weld out, vee it again and repeat the process. the second time you won't have any holes.

bob g

 

The crack is about 6 inches long and goes to an edge of the part. The bell housing is about 1/2" thick.

What do you all think of that Muggy welding rod? Too good to be true, or worth trying?

 

i'd be AWEFUL suspicious of that rod. understanding a little of the metalurgy of welding cast iron i don't see how it could really work that well.
i'd use the nickel rod and "V" the crack like Brutus said. then heat it with a torch til it's nice and red (preheat), weld it up, then pean it, heat it (post heat) and bury it in a bucket of sand to let it cool slowly. the idea is to get all the molecules to flow together so it becomes one piece of metal again. good luck and let us know how it works out.

 

THANKS guys I did what you guys said used the muggy rod.Also tryed it with nickle rod also,didnt see much difference .The muggy rod has more copper color to it.