Welding a cast iron tool (Roper-Whitney XX punch)

Sodo · Apr 30, 2015

George, thanks for your reply. I am quite interested in the process to repair "cast" and will remember the process you generously outlined above. If this was a valuable, and irreplaceable tractor part, I would follow your every word!

My method must be possible with the tools I have. I don't have a mill, no reamers, no way to thread a bush to match the punch die thread. And no oven. Furthermore this tool is not worth much. I'm repairing it for the sport of it, and because,,,,,,, well I just have to do it

its in my blood to try. I generally achieve more success in metal "repairs" than I do in my garden, for example.

Also I have this notion that other members are interested and/or inspired by the discussion and learning (failure or success). Like a "reality TV show"

. Your reply is a genuine pearl and I bet many members will put it in their bag of tricks.

Vee-ing it out to a point in the center is certainly the way to do a complete repair, but I doubt it requires much strength at the chosen cut location (near the end). It's a "hand tool". At this point I think I have to do it as Piloon described above, the most important task being to achieve and retain alignment.

Do you think MIG tacks will stick well enough to hold alignment - such that I can braze it in-place? And do you think the alignment can change during brazing or cooling?

george md · Apr 30, 2015

Mig is an arc weld , it will like any other arc weld , create a hard and brittle zone next to the weld.
that requires the normalizing process to soften it.It is caused by the rapid cooling around the
weld . There is no such thing as cold welding with an arc as it is extremely hot and the surrounding
metal is cold and chills the fusion zone .

Vee it to the center and braze it from both sides to keep it reasonably straight .

I do quite a bit of cast iron welding , a few things are posted in the image event file.

george

muddstopper · May 1, 2015

George, got to ask. After looking at some of your repairs to manifolds, it appears you where not using brass, What kind of rods where you using? Also got to say for some of those repairs, you have much more patience than I have.

Sodo · May 1, 2015

I'm using my Jawhorse with the "welding attachment". First time using the "welding attachment" since last November. I was a little worried it would be one of those accessories that never gets used, but this time it really fits the bill, holding the cut end in position.

I had to reef on it and tack on place, it changed with each tack. I had to bust it off once and start over but I feel like I may have outsmarted it because it's centered nicely at the moment. But it may get the best of me yet.

Tacked up, it's all I can do to resist the urge to just go ahead and weld it up (with the MIG)

You can see that I v'd it out in case I couldn't resist the MIG. Afraid it would move all over though, seems like brazing is more feasible.

Patience is a virtue.

Shield Arc · May 1, 2015

If you do use your Mig welder, try some Silicon Bronze.
MIG Welding Cast Iron

Sodo · May 1, 2015

Thanks for the MIG link, good reading. I'm sure brazing is the way to go. Gonna just put this thing on the shelf and wait until I get ahold of my O/A rig and the weedburner (for preheat).

Mace Canute · May 1, 2015

Just a reminder...don't forget to remove your punch and die before you start preheating and brazing it.

george md · May 2, 2015

mudstopper,

The rod is cast iron in stick form ,usually 3/16 or 1/4 inch square and most rod now is round

and in the same sizes. 1/8 was available but is scarce now. The best flux I have used is Superior

anti borax , harris welco has a good flux also . Rod comes from harris welco or from Tucker valve

seat co in odessa texas.

I have been welding cast for something over 35 years , slowing down now, don't do as much.

Where in western NC are you , I been to Marion just off I40 many years ago.

george

muddstopper · May 2, 2015

George, you have to go about 140miles further west to get to Murphy NC. Its right on the Tenn/Ga state lines. About as far west as you can go and still be in NC.

I have seen cast iron rods before, but never used them. I have taken a piece of cast iron frying pan and used it to weld a fruit press one time. It wasnt easy. One little trick I did learn from that little experiment, If you want the piece to look like it hasnt been repaired, sand everything smooth and than take some coarse sand paper and wrap the sanded area. Take a small hammer and just start tapping the sand paper. Key word here being tap, not hit. The sandpaper will leave little divets all over the smooth area making it look like the original casting surface. This makes it really hard to tell there has been any repairs made. Ornamental old iron like the old fruit press is about the only cast welding I even try to do. Sort of like Sodo's project, if the weld hold fine, if it doesnt all I have lost is a little time.

jwmorris · May 2, 2015

I use silicon bronze filler and a TIG with good success on cast iron.

I would have bushed and bored it myself though.

It's just a hand tool but develops a lot of force. Go get a paper hole punch and try poking a hole in steel and you will understand there is a lot more force generated than you might think.