The Armour Archive

I've got an old harbor freight 50 lb. anvil, probably cast iron the way it's held up to hot work (the face has chipped at the edges). The face measures 3.5" x 9".

I've found a piece of 1.5" thick 4140, 4" x 9.5", which is about 1/4" longer than three of the four sides of the anvil face. I'd like to mig weld it on at those bottom edges, hoping to make this a decent small anvil.

I'm wondering what the best Rc hardness should be, and I'm concerned about welding 4140 to cast iron, as in I'm thinking it might need pre-heating, or the weld might get brittle and break... or there are probably tons of things I'm not thinking about.

Thoughts?

you cant mig weld cast iron and it will not be any good just fixed round the edge.
you might be able to put a single piece of 5/16 or 3/8 round from end to end on it and then clamp it to the anvil so you can stick weld with cast rods each side of the round alternately so you get the entire area welded but cast rods are expensive.
if your block was larger it would make a good block anvil

I stick welded a crack in a cast iron frying pan earlier this year. It did not go according to the initial plan.
I got specialty stick for cast iron. When I stick weld I like to spitball the amps (mine is infinitely variable) but I always spitball it low and dial up as necessary. I don't remember what I tried initially but my 1/8" electrode blew a 3/8" hole right through it. I had to dial it way, way down, like to 40 amps, to cool off the spark to the point where I could work with it. And then it felt like I was welding a kitchen sponge. It just wanted to fall apart.

So without even getting into whether it's a good idea, just based on my limited cast iron welding experience, I'm not at all sure how I would go about it. The materials behave very differently under a spark (well a stick spark, anyway).

I hear Fischer perfected the welding of a tool steel surface to cast iron, but the way they did it was to heat up the plate of tool steel to welding temperature, flux it, and then pour the molten cast iron on top of it. I haven't heard of another successful method. I think the problem with your plan is going to be welding the middle of the plate. I've read about using hard facing rod to stick weld a whole hardened surface on old anvils, but I'm pretty sure we're not talking about cast iron in that case. Plus it's generally regarded as one of the more pain in the ass methods to get a working anvil.

If I was you, I'd look for a larger chunk of 4140 (2" or more thick) and use that mig welder to weld feet to it, then bolt it to a stump and use it. Come to think of it, 1.5" would probably work out fine for smaller work. If you can secure it to something heavy it would be fine - there are a lot of treadle hammer and tire hammer "anvils" (in the form of dies) that are around 1.5" and are used to form some really thick stock... but the trick with those is they're well secured to something else that makes up the mass.

fisher use cast steel not cast iron for the body of their anvils

Its doable but your throwing good time/money on an ASO.
Look for a real anvil or a piece of structural steel/rail track.
Some of the maintenance rod will work for transitions between dissimilar metals.
6013 has done well for me in the past welding stuff to tractor weights and other found objects.
Cut a V groove and run it like a butt joint. 6013 root and use multipass to fill things and file flush.
Any voids or inclusions can really weaken the joint.

I promise that ANYTHING you try to do to join those pieces of metal will be a losing battle. You're either going to spend more than a steel anvil would cost just in electricity/propane/coal and welding rods/wire, OR you're going to spend someone's else's money that they don't realize yet if you're welding this at someone's shop. Either way, you're still going to make something that will be disappointing. To even approach getting a solid full face weld, tou'd need to bevel edged until the two pieces met like the letter K [with the anvil on its side and the plate as the straight line of the K] and FILL those triangles with perfect weld.

If you tried to do it the RIGHT WAY, you have to do what Fischer did, which means melting the cast iron anvil, doing the magic to make cast iron into cast steel, making a mold with your hot 4140 plate in the bottom, and pouring the cast steel in. And when it fails, you have to try it again. No one man or small shop is equipped to do this SAFELY and COST EFFECTIVE. If you don't die, you'll still have spent more $$ than a new anvil with a high chance of getting a dud.

I only know this because I didn't believe the blacksmiths I asked 15 years ago, so asked my father [mechanical engineer] if his employer [specialty space stuff] could quote it? They asked for $25K and a "no fault" clause if it sucked when they were done. Then my dad worked out the math and showed me the electricity costs. Insane.

On the other hand, you can spend that time calling fork lift companies and asking for a broken fork. At today's gas prices, you can afford to drive pretty far to get it and still spend a fraction of what you'll spend trying to weld a face on a cast iron block.


Call scrap yards and ask for a bent/damaged fork lift tine. With an angle grinder to cut part of the foot off, you get a far superior anvil. Pay for a good welding job at the local fabricating shop, and you've got two.

http://marco-borromei.com/fork.html

NO Fisher used cast iron---get a copy of Anvils in America and read the patents! It's also why Fishers don't ring; but they are a good anvil anyway. My main shop anvil is a 515# Fisher. (The owner of the Fisher Museum hangs out over at iforgeiron.com you can double check with him if you wish. NJAnvilman IIRC)

Best way to fasten 4140 to a cast iron ASO? Sell the ASO as a garden ornament and buy a heavy chunk of STEEL with the money and then do a full penetration weld on it---space it off the surface of the chunk and weld up the entire joint from the middle of it to the outer edges. Pre heat of course... Now if it is the Russian cast steel one you might have a chance. Spark test or drilling on the bottom will show which. Generally cheaper to just buy a bigger chunk to start with and avoid welding.

The general advice boils down to "don't".

Since most armour work doesn't actually need, or use an anvil, it is not bad advice.

You have a very nice lump of steel. Which could be used for power anvil hammers or anvils. Or small flat anvil surfaces... or lots of tooling.

I used 2 pieces of 1 1/2 x 4 x4 to make a power hammer "hammer" and a dishing anvil. I don't actually use the dishing anvil, but the hammer is perfect. I use the flat anvil instead. You could make one of those easily. It doesn't need to be as big as the plate you have now.

Wade