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

[ruffdog]

I've got the Roper Whitney #5 and it works great and says "made in usa" on the side.

 

[RedNeckGeek]

If I remember correctly, you'll need a high nickle rod to weld cast iron, and also preheat and post weld heat treat to avoid creating a brittle microstructure in the heat affected zone around the weld. It's also going to shrink like crazy as it cools, so the alignment for the punches would probably be destroyed. Welding would be my method of last resort. In my shop, I'd use the vertical mill to bore out the lower hole and install a bush. If there's not enough meat there, your idea of cutting could work, but I'd use silver solder for reassembly. You're going to have to keep the punches cool during brazing or they'll lose their temper and go soft, and that thick section of cast iron is really going to take a lot of heat. Might be worth while turning up an appropriately sized rod to act as an alignment pin and use that instead of the punches.

Years ago I bought a used HF three-in-one sheet metal machine on which one of the half moon shaped arms had broken. It was also cast iron, and the two pieces fit well together across the break. I cleaned it all up on a wire wheel, fit the ends together on a big fire brick, then went after it with a rose bud tip in the oxy-acetylene torch. Used lots of Handy flux and just kept feeding in the silver solder until I saw it wet out the other side of the crack. Let it all cool down nice and slow, and that repair is still going strong.

Backing up, ask yourself how the punches came to be misaligned in the first place. Is the frame so soft that it bent from just the hand pressure on the handles, or are there marks that show someone put them in a vise or used a hammer? If the former, brazing sure isn't going to do anything to help make it stronger, and I'd sure be pi$$ed when it bent again after spending all that time to fix it. What do the reviews at the HF web site say? Do they all bend like that?

 

[LD1]

I wonder if it is actually cast iron if it got out of alignment without cracking already. Maybe cast steel?

I might try a little heat and squeeze it together a tad in a vice?

 

[Leejohn]

I sure like the heat ideal 1st then my ideal with the screws 2nd.

 

[Sodo]

My 3 in one shear/brake/roller broke same as yours but across one of the holes. I thought of brazing it but never got a round tuit. It sat broken for 8 years then I went to HF & they sold me a new curved part for $18 which was easy enough.

This punch is new, never used (its not usable). Its not shown on the HF site. I suppose somebody bought a lot of reject tools somewhere and was eBaying, hoping for the best. The bores appear to be "misaligned parallel" as best as I can tell. Due to the "C" shape I doubt the bores would remain aligned if squeezed.

My current plan, unless something better comes up is to tack it in-place with an arc-welder, remove the die, then braze. Under that plan, how would I cut it? Have a Sawzall, grinder, cold cut saw -yikes (carbide), a diamond type blade that I use for tile,,,,,. I have never cut cast iron but have "ground" it and it grinds like a rock. How would I know if its cast steel and what difference is that?

 

[Shield Arc]

How would I know if its cast steel

Spark test.

 

[Sodo]

This cut took 5 minutes with the angle grinder, it was "easy". As easy as it was, with 20/20 hindsight I would have increased the angle (made a longer cut).

I suspect it's cast steel. It grinds more like steel than like a rock. Here's a pic of a centerpunch mark, it looks to be a little bit ductile. If I could just Vee it out, preheat it and weld the circumference that would be pretty darn quick. I know the concern of welding cast ---- is a crack growing along the weld juncture (as it cools). Where the weld easily separates from the base metal. Can anyone offer genuine experience that relates --->specifically<--- to this project?

The outcome I would like is learning and success, but keep in mind I am doing this for sport (and I prefer to win). One hour shop time and able to withstand as hard as I can squeeze on the handles is a "win". I don't consider the internet time to be shop time (,,,,keeps me off the streets ).

 

[RedNeckGeek]

This cut took 5 minutes with the angle grinder, it was "easy". As easy as it was, with 20/20 hindsight I would have increased the angle (made a longer cut).

I suspect it's cast steel. It grinds more like steel than like a rock. Here's a pic of a centerpunch mark, it looks to be a little bit ductile. If I could just Vee it out, preheat it and weld the circumference that would be pretty darn quick. I know the concern welding cast - is a crack growing along the weld juncture as it cools. Can anyone offer genuine experience that relates specifically to this project?

The outcome I would like is learning and success, but keep in mind I am doing this for sport (and I prefer to win). One hour shop time and able to withstand as hard as I can squeeze on the handles is a "win". I don't consider the internet time to be shop time it keeps me off the streets.

Many years ago I earned a Welding Engineering degree from Ohio State, and though I haven't applied it specifically to welding cast iron, I've related what was taught there and believe it to be true.

Regardless, your use of a cutoff wheel has left you with a gap too wide to bridge with braze metal. To continue in that direction, you'll need to find a piece of shim stock, low carbon steel will do, the width of that gap and braze both sides of it to your two pieces. It could be done with one application of heat, ideally with foil shaped braze metal to form a sandwich.

As far as how much carbon is in the material you're dealing with, you could melt a small spot in a non-stressed area (out on the web at the end of the lower leg opposite the punch hole would do), then try to cut it with a file or drill bit. If the tool skates off the surface, you're dealing with something that will harden in the weld heat affected zone. If it doesn't crack on cooling, it would likely do so the first time it was dropped, or when you tried to use one of the larger dies on an age hardened piece of aluminum. If the melted spot stays soft, you could try welding, but then you're going to have to find a way to keep the two bores aligned. You might get away with it if you created a v-groove symmetrical about the center line, then applied the weld beads so as to balance their application evenly from side to side. Or you could try scabbing pieces of steel onto the sides, but again you'd have to be careful to apply the beads evenly to end up with anything close to workable. Even then, it would be a guess as to how much to allow for weld shrinkage that would tend to move the two pieces closer together.

I guess is that the good news is that at this point you've got nothing to lose but your time and a little elbow grease. However it turns out, let us know, OK?

 

[Sodo]

If this tool was dropped, a die could be ruined. I don't intend to drop it.

Will try the melt & file test.

I was thinking that if I could tack it in position with a wire feed, then fill the gap with brass. You're saying I can't fill that gap with brass? The sandwich filler makes sense too but are the braze temps & flux compatible (betw mild steel and cast steel)? I can't recall seeing mild steel brazed to cast iron in other construction, but maybe it's done.

 

[Shield Arc]

Member here George Miller does cast iron repair for a living.
4437 Prospect Rd ,Whiteford ,Md 21160
I think it was George who recommended these products.:confused2:
TM Technologies - Cast Iron Flux and Filler Metals