One of the small projects I was working on today, was an older Spyder that a local customer had gotten cheap/free because the previous owner attempted to do a "trigger job" to it- apparently with a bench grinder.
Now, this is actually a pretty easy fix. Here's a trick; music wire works great as a sort of hardfacing rod. It's fairly high-carbon, and because a small button-weld/tack-weld cools very quickly (even on a small part like a sear) it pretty much self-quenches, leaving a fairly hard surface.
I usually dunk it in water immediately after welding, to help it along. It's almost impossible to get it so hard it's brittle, but with a bit of luck, you can get a fresh surface that's too hard to file.
After that, just shape and dress with a grinder/Dremel and some stones, and you're back in business. Assuming you already have a TIG in the shop, it's way faster than trying to order a replacement sear, or find a "parts" gun to strip.
Anyway, as I was doing this one today, I reflected that it'd be nice if I could do the same thing to my anvil.
My anvil is a very good-quality Peter Wright that's very likely a little over a century old. (Roughly 1885 to no later than 1910.) The face is so hard it flattens a centerpunch that can put a dent in a new Nicholson file. I'm guessing somewhere around Rockwell 70C, but that's no more than a guess.
However, as good as it is, it's been used hard for much of that intervening century, and is now badly chipped, slightly swaybacked, worn down, rounded over and blunted. There is nothing even close to a sharp corner anywhere on the working face. The best spot still has no less than a 1/4" radius.
I've heavily researched methods of fixing it, mainly looking at hardfacing rods for stick welders. I went so far as to buy over $100 in rods, only to find out they didn't work for beans.
Doing another one of these sears got me thinking; hardfacing TIG rod, while much slower, might work where the stick rod failed. If I worked on a very small area at a time, and made very small and short beads, I suspected that I might just be able to build up the corners- and just the corners- with some steel that, while not as hard as the main face, would at least be much harder than plain MIG wire, and probably somewhat harder than even good hardfacing rod.
So as an experiment, I tried it, working from one of the back corners. Here's what I started with:
I ground out most of the rust...
And tried a little bit with some 1/16" music wire. It worked, albeit being slow. I kept a wet rag on hand to "quench" the welds even further- or at least to keep any residual heat from drawing a temper out- and I ended up with beads that were for the most part too hard to file.
Hardness varied a bit, though, as there were definitely spots soft enough to file, but even this would be acceptable, if no other options were available, simply to get a usable square corner or two.
But that made me think- what if I had an even higher-carbon-content filler rod? Something that'd land file-hard if you so much as looked at it funny. So I started thinking, what do I have that would be a very-high-carbon steel, but close enough to "filler rod" size that I could actually weld with it?
After pondering that one for a few more hours, it finally hit me:
Needle bearings! These are the "loose" needles out of an old truck universal joint spider, a little over 1/16" in diameter and roughly 3/8" long. I know bearing steels have a lot more in them than just carbon, but I also know they come very, very hard.
So after making a reservation for a nice, padded room over the weekend, I sat down to try and weld a 140-pound anvil with filler rods three-eighths of an inch long.
It was actually pretty easy, just time-consuming. I'd take a moment to tack up six or seven short rods, each with a bearing on both ends:
... Which was a simple tap-and-tack with the TIG.
I'd make a bead of about one bearing long, and immediately quench it with a wet rag. I stopped frequently to let the anvil cool- it never got "hot", but I wanted it as cool as possible for maximum quench on the welds.
I was just experimenting, so I was only doing a small section. It still took a while, but eventually I had a decent build-up:
And, with a little grinding and sanding, I have a corner again:
It's not perfect. There's definitely a few softish spots, but the bulk of it is too hard to file. The "seam" between the weld and the rest of the face is shallow, and only there because the top face is "domed" slightly. I don't (yet) want to grind it down to meet flush, in order to preserve as much original face as possible.
It's also horrifically slow, and very costly in shield gas.
But, all that said, if I do it a little at a time, and take my time, I think I can restore most of the corners to a useful state, as well as repair other damage like that spalled crater seen in the pics, aft of the hardy hole. (The hardy will probably also get it's corners built back up, as well as filling in that chip in the pritchel hole.)
Of course, while I had the big heavy lump up on the welding table, I figured I'd take care of at least one other thing that's been bugging me. The nose, or horn, has lost at least half an inch, and was thus badly blunted:
This ones' easy, though. The horn, like the bulk of the main body, is mostly pure wrought iron, which meant I needed nothing more sophisticated than a good MIG to patch it.
First, clean off the rust:
Then just squirt some hot steel on...
The just grind to shape and sand smooth.
Took perhaps ten minutes, all told. Easy and quick, and not only restores some needed functionality (like for these) but also makes it look better. More complete. Not a big thing, but hey, I'm the guy that polished and gun-blued his hammer, okay?