Induction forger


#1

Is the induction forge up and running? Is there any special training required, or have we moved any tools back into the metal shop? My son is dying to forge a blade, and I’ve got railroad spikes ready to go. I live a good distance away or I’d just go look for myself.


#2

It is up and running. I think training is recommended; not sure about “required”. Also not sure on tools. Chuck is willing to show folks how to use it if he is available & asked nicely. I am reasonably sure others will, too. David K., I think?
Hell, ya know what?
I really just wanted to show off some really cool product by @HankCowdog:


Interested in the other answers you get; hopefully more helpful than my own…


#3

Its up and running. There is tongs and hammers next to the anvil. You should be good to go! Training is not officially required. Its not complicated and “training” takes all of 5 minutes. If you ask around im sure you can find someone to help you out


#4

Cool! I have an antique file I want to soften up and make a knife from. :grinning:


#5

FWIW, based on the little bit that I’ve played with the induction forge, I’m not sure knife making is its best use case.

Generally, you’ll want to heat the entire length of the knife’s blade, which would require constantly moving the blade forward and backward through the small coil. It’ll be difficult to get an even, hot heat along the length of the blade, and differential heat is an invitation to introduce stress into the metal.

You might be able to do the initial annealing in a gas or coal forge, work the annealed metal in the induction forge to shape it, then go back to a gas or coal forge to heat for quenching/hardening.

Also, FWIW, railroad spikes don’t have enough carbon in them to harden well enough to make a knife. You can make a KSO (knife shaped object) but it won’t hold an edge.

Since files are high carbon, they can make nice knives. You can incorporate the file texture into the finished knife if you are careful in the forging.


#6

image

Right?


#7

Excellent. I’m not scared of it, and I can work a gas forge, just wanted
to make sure I don’t get my hand slapped. That sounds like a ton of fun.
Any idea what width and length it can accommodate for flat stock?

Is there any problems with quenching (hardening) in the metal shop?
Assuming oil not water.


#8

Luke’s example shows an interesting and valuable point: You can adapt the coils to you own special needs. Basically you just need copper tubing and the compression fittings.

I believe someone is adapting a coil so fit around a small crucible, it will taper to follow the conic shape.

So you knife makers need to get together and make up some special coils.


#9

I did not know that. I thought that it was the opposite. I’d been reading about people making knives from railroad spikes because they were hardened, and had high carbon content. I admit I have very little practical knowledge so I must have been confused.

Anything that requires the gas forge will require bringing the trailer back, and I was hoping to avoid that.


#10

That is an excellent idea. I would not mind doing that and leaving it there as an interchangeable part. The electric forges I’ve seen before were more of a tunnel that you stuck the metal into rather than two tubes. Technically it was tubes wrapped in a circle around a length. I’ll look into options.

https://www.youtube.com/watch?v=lt-g-xYc98k


#11

Hopefully, at next space we can put in venting for the gas forges. They can safely be opertaed inside as long as vented.


#12

Yep. Railroad spikes are listed as high carbon, but not high enough for knife making. Guess I’ll be finding a file.

http://www.cartercrafts.com/carbon_myth.htm


#13

So there is documentation on what length to make the coils. Also they are a metric flare fitting as well. I don’t know if the flare is a standard 45* or some other chineesium degree angle. :rofl:


#14

Spikes probably work fine if using a coke fired forge as you will be introducing more carbon into it.


#15

Good point. I’m not sure it could make up the difference though. They would need 3-5 X the amount of carbon as it already in the spike. Also not sure how deep that penetrates.


#16

It usually occurs when the metal is folded over enough times that your arms are ready to fall off. It incrementally introduces carbon more uniformly.


#17

A coil like Luke’s “coil” would probably work much better than the one currently on the the induction furnace.


#18

When heated in a coal forge, carbon gets introduced into the metal through folding. Heated in the induction forge, there’s no source for carbon, so oxides (aka “scale”) will form and will tend to get folded in instead unless a lot of flux is used. Even in a coal/coke forge, LOTS of folding and layering is needed to increase the carbon content more than simply case hardening the surfaces.

One usually wants a reduction heat (as opposed to an oxidizing heat with excess free oxygen) to allow the metal to heat without creating scale. Scale will prevent the layers from fusing together properly. Reduction heat is more easily obtained in a coal/coke forge than a gas forge, and impossible to obtain in an induction forge without adding a shielding gas (which we are not set up to do) or shielding flux.

“HC” (high carbon) railroad spikes are relatively high carbon, as compared to non HC spikes. With only about a third of what one would desire for holding an edge, they are not high carbon from a knife- or tool-maker’s perspective.

Coil and leaf springs, as well as files and rasps, all have enough carbon % and can be acquired relatively cheaply at junk yards and/or flea markets/garage sales. I have several farriers rasps from our hourse trimmer if someone would like one to play around with.


#19

I’ve seen enough Man at Arms to confirm that spring steel is apparently the ideal material for making various blades without incurring significant materials cost.

It is quite cheap- often free if you know where to look, so it definitely has that going for it.


#20

@Photomancer Where’s the next space going to be? And when?