Need to weld a part that is cast....something

[txfireguy2003]

Yesterday, I was at the old man's house and he asked me to try to repair the table on his drill press. The collar that clamps around the upright post of the drill press has the clamp tab broken off on one side. I know the part is cast, but not sure if it's cast iron or cast steel. It's an older Craftsman unit, so I'm assuming probably cast iron, but how do I figure out for sure? Secondly, any recommendations on procedure, electrode etc, considering that I have only an AC stick welder with max output of 140 amps? Thanks in advance guys.

[ShieldArc]

Yesterday, I was at the old man's house and he asked me to try to repair the table on his drill press. The collar that clamps around the upright post of the drill press has the clamp tab broken off on one side. I know the part is cast, but not sure if it's cast iron or cast steel. It's an older Craftsman unit, so I'm assuming probably cast iron, but how do I figure out for sure? Secondly, any recommendations on procedure, electrode etc, considering that I have only an AC stick welder with max output of 140 amps? Thanks in advance guys.

Just braze it.

[Rocky D]

First, do a grind test on it to see if it's steel or iron...my guess is it would be steel....steel sparks are yellow...iron are red.
Then if steel weld it with what ever you have...6013 would be OK or if iron, that's more involved, but do-able

[atlantafab]

This look anything like the craftsman part you're thinking about fixing?

[txfireguy2003]

This look anything like the craftsman part you're thinking about fixing?

Slightly different design, and there is no damage to the ring, just the "Tab". But, yeah, it's the same basic part. I'm thinking the one I'm looking at is probably a little newer than that one, probably made in the last 30-40 years or so.

Thanks Rocky, you've made it much easier. I've read all about the grinder spark test and it all just too dang confusing to me. Yellow=steel, red=iron....pretty simple! So, assuming it's steel, I would still have to preheat and post heat the part, right? Since it's cast?

[Zrexxer]

With all due respect to Rocky I'd almost guarantee that's not steel. Sears used plain old cheap gray cast iron for all that stuff. You can usually look at the fracture and tell too; cast iron exhibits a brittle fracture with a rough dull surface that looks sandy. You're going to have a challenge repairing that part in that location so that it stays fixed.

[txfireguy2003]

With all due respect to Rocky I'd almost guarantee that's not steel. Sears used plain old cheap gray cast iron for all that stuff. You can usually look at the fracture and tell too; cast iron exhibits a brittle fracture with a rough dull surface that looks sandy. You're going to have a challenge repairing that part in that location so that it stays fixed.

Yeah, I figured it would be difficult, but thought I would give it a try. Surely he can buy a new one if he has to, but I figured I'd at least give it a shot.

[Rocky D]

OK, if it's gray cast, then you would need a ni rod that will run on AC, (I'm not familiar with any, I always used Certanium 889, in TIG mode), then to keep your alignment you put the part together before any grinding, so thet you use the fracture irregularity to align the part...then tack opposite ends/sides to hold it while you grind a sufficient groove to get your weld in, then preheat to take the chill out, and weld it while it's still hot, if you can, grind the tacks, and weld, but if you can't no problem, just emerse the hot part into kitty litter, or wrap in fire blanket, Kaowool, to keep the heat in, and let it set till it's cool. Your alignment will be right on, with this method.

[txfireguy2003]

OK, if it's gray cast, then you would need a ni rod that will run on AC, (I'm not familiar with any, I always used Certanium 889, in TIG mode), then to keep your alignment you put the part together before any grinding, so thet you use the fracture irregularity to align the part...then tack opposite ends/sides to hold it while you grind a sufficient groove to get your weld in, then preheat to take the chill out, and weld it while it's still hot, if you can, grind the tacks, and weld, but if you can't no problem, just emerse the hot part into kitty litter, or wrap in fire blanket, Kaowool, to keep the heat in, and let it set till it's cool. Your alignment will be right on, with this method.

Thanks Rocky, I probably would have never thought of tacking the ends to hold it in alignment! I would have been clamping and all sorts of other junk. So just enough preheat to knock the chill out of it is all I need huh? And you don't know of any Ni rods that run on AC, or you're just not familiar enough with stick welding on cast to know for sure? Wow, that sounds like you don't know what you're talking about...rest assured, I didn't intend for it to sound like that, I just couldn't think of a better way to word it at 0130! Anyway, thanks again, I'll have to go to the LWS in the morning to get gas for the torch anyway, so I'll just ask them about a Ni rod that runs on AC... assuming I need one that is, hopefully it's cast steel, but not sure yet.

[atlantafab]

Nickel AC Rods?

Hobart's got to have something.
If not, I bought some LEO7230 (99%) AND LEO7233 (55%) 1/8" dia. in the past. You could once get them in 1 pound boxes. Use AC or DC+.

That Drill Press part is definitely red spark/iron. I don't even know why I have mine still. I guess it's in the "sculpture" parts pile. Normally, i stay away from strtuctural cast repairs.

[Rocky D]

...So just enough preheat to knock the chill out of it is all I need huh? And you don't know of any Ni rods that run on AC, or you're just not familiar enough with stick welding on cast to know for sure? Wow, that sounds like you don't know what you're talking about...r....I'll have to go to the LWS in the morning to get gas for the torch anyway, so I'll just ask them about a Ni rod that runs on AC... assuming I need one that is, hopefully it's cast steel, but not sure yet.

Like I said , I've only used Certanium, 889 ...that's a stick rod...for TIG, I wire brush the flux off, and I've never lost a weld with it...for the preheat, you will bring it up to temp by the welding on it...if it were a larger casting, (like 1 inch thick) I would preheat, and post heat. For something small that you can do on the bench, making it cool down slow like what I mentioned above, will work fine.
Momma's oven will work, too...leave it in there at 300° for 6 hours or so, and reduce the heat slowly.
Now, you will also notice I haven't mentioned peening...the reason is, most folks have heard you're supposed to peen to reduce the stresses, which is true, BUT it is an art, you really have to understand how much to peen...I have seen many times guys that peen a weldment and have it break beyond repair...the reason for peening is that the weld metal you add to the part shrinks at a greater rate, that the base metal, so you compress it by peening just enough to combat the shrinkage...it's the "just enough" that is the tricky part.

[smyrna5]

OK. The guy I welded the window box for earlier this year just won't believe I am not a welder, especially since the window box is still holding strong. Another mutual friend had me weld a big gate with his Thunderbolt despite the fact that I had only burned 5 rods with a stick in my life. It was pretty ugly to my eyes, but still holding strong so that didn't bolster my case!

Now this guy wants me to weld a garden bench leg back together. I did the grind test on it, but the sparks look orange to me, so I am not sure if they are red or yellow I'm not sure if its iron or steel, but the fracture looks pretty granular



I told him I would probably have to hit it with the stick, but do I use a steel rod or Ni?

[Hotfoot]

OK. The guy I welded the window box for earlier this year just won't believe I am not a welder, especially since the window box is still holding strong. Another mutual friend had me weld a big gate with his Thunderbolt despite the fact that I had only burned 5 rods with a stick in my life. It was pretty ugly to my eyes, but still holding strong so that didn't bolster my case!

Now this guy wants me to weld a garden bench leg back together. I did the grind test on it, but the sparks look orange to me, so I am not sure if they are red or yellow I'm not sure if its iron or steel, but the fracture looks pretty granular



I told him I would probably have to hit it with the stick, but do I use a steel rod or Ni?

Well, if that legs lets loose, its going to do it right after its been moved, and then when old frail grandma sits down on it. Think about that, Smyrna...might be the one to avoid because its kinda like "nothing that travels on public roads" when you're not sure if it'll take a good weld or not.

[smyrna5]

Well, if that legs lets loose, its going to do it right after its been moved, and then when old frail grandma sits down on it. Think about that, Smyrna...might be the one to avoid because its kinda like "nothing that travels on public roads" when you're not sure if it'll take a good weld or not.

Good point.

The guy claims that both the window box and the bench leg were broken by his gardener. The gardener claims he broke the bench leg with a string trimmer lol. That must have been one **** of a string.

[Zrexxer]

Now this guy wants me to weld a garden bench leg back together.

Sometimes even though we have a hammer, not every problem is a nail. If there's enough straight area on that bench leg, it looks like you could simply make mild steel flat bar bolted-through fish plates spanning the break. It might not be as cosmetically pleasing but with care it probably wouldn't be noticeable and it would be strong.