Second remelt, WIP

[Joshua States]

I tried another steel remelt last weekend using a short stack furnace. I think the results were a little better this time than last time, but the jury is still deliberating. This was done with 3 pounds of 4d cut nails, (1.5" long) using some of my pine charcoal.

Here is the short stack furnace with the pre-heat burning.

And running the melt

At first I couldn't find anything in the furnace digging around with my tongs, so I let it cool down a bit and finally pulled something solid out of the very bottom. Here is the puck, blob thingy.

This thing was incredibly hard to forge. I had to do most of it very carefully with the press. I cut it into two pieces and wound up with three short bars about 3/4" square.

I might not  get back to this for a while. We are planning on moving May 18th.

[Alan Longmire]

Looks good!  I bet it's very high carbon.

[Ron Benson]

I am new here, so please forgive the noob question, but what was the yield, (or is that even important)? You started with 4 lbs - what did you wind up with?

[Joshua States]

1 hour ago, RonB said:

I am new here, so please forgive the noob question, but what was the yield, (or is that even important)? You started with 4 lbs - what did you wind up with?

Welcome Ron. Not a noob question at all, maximizing yield is one of the targets for this endeavor. The three bars weigh very close to 3 pounds. There are a couple of smaller pieces that I haven't tried to forge yet that weigh an additional half pound.

[Joshua States]

2 hours ago, Alan Longmire said:

Looks good!  I bet it's very high carbon.

I don't know how good it looks. It looks like a mess to me.... I'm no expert at spark testing either, but here is a photo of cutting the puck with an angle grinder

[Will Wilcox]

Looks like pretty high carbon. Quench and break test a little piece, maybe? 

[Alan Longmire]

That's the thing about hearth steel, it's always ugly right out of the fire, and always a bit crumbly during reconsolidation.  That puck looks high enough carbon that the several welding heats it'll take to make it sound won't decarb it too far to be high carbon at the end.

[Zeb Camper]

Cool! Good luck on all the folding and stuff. I'm real interested in seeing how it turns out. 

[Joshua States]

13 hours ago, Alan Longmire said:

That's the thing about hearth steel, it's always ugly right out of the fire, and always a bit crumbly during reconsolidation.  That puck looks high enough carbon that the several welding heats it'll take to make it sound won't decarb it too far to be high carbon at the end.

I hope you know what I'm doing, because I don't have a clue........

Edited April 13, 2018 by Joshua States

[Alan Longmire]

14 hours ago, Joshua States said:

I hope you know what I'm doing, because I don't have a clue........

...  I know just enough to be dangerous, and possibly to help you get something usable out of it.  Emiliano and Daniel Cauble can really help you dial it in.  What you have now is a wad of gigantic-grained, cracked, almost cast iron-like steel, which is the normal result of this process.  A couple of normalizations will reduce the grain, then you're gonna have to weld it into itself a few times to close up the cracks.  Always draw it in one direction only, don't try to spread it around.  Oh, and after the welding up, pretend it's wootz.  Don't work too hot, don't work too cold, don't hit it too hard.  Unfortunately, the only way to know if you're doing any of those is when it falls apart on you.  

[Joshua States]

10 hours ago, Alan Longmire said:

What you have now is a wad of gigantic-grained, cracked, almost cast iron-like steel

Yep. That's an accurate description

10 hours ago, Alan Longmire said:

which is the normal result of this process. 

That's a relief.

10 hours ago, Alan Longmire said:

Don't work too hot, don't work too cold, don't hit it too hard.  Unfortunately, the only way to know if you're doing any of those is when it falls apart on you.

How the heck did Snorri Oglafson ever figure this stuff out? Trial and error? Pig headed determination?

[Alan Longmire]

7 hours ago, Joshua States said:

Trial and error? Pig headed determination?

Both are required in great quantity.    Don't be afraid to flux the heck out of it during the welding heats.  

[justin carnecchia]

Fun stuff! I tried making my own once, finally got a decent chunk of steel but blade took three tries to harden and on that try cracked severely. Hoping to try again soon.

What are your plans for the steel if you're able to get it condensed into a billet? Historic or modern?

Best luck, Justin

[Joshua States]

On ‎4‎/‎18‎/‎2018 at 9:57 PM, justin carnecchia said:

Fun stuff! I tried making my own once, finally got a decent chunk of steel but blade took three tries to harden and on that try cracked severely. Hoping to try again soon.

What are your plans for the steel if you're able to get it condensed into a billet? Historic or modern?

Best luck, Justin

Justin! Good to see you back in the forum. What have you been up to?

Definitely historic. Very historic. I've been wanting to semi-recreate this with some pattern welded bars

I'm hoping to get some steel good enough for the edge bar.

Edited April 26, 2018 by Joshua States

[Joshua States]

Well, it's only been 2-1/2 years and I finally got around to forging this thing out some more.

When I last left off, I had made three small bars that were still pretty unstable.

 

 

These got stacked and I attempted to weld them together. After having a bunch of stuff crumble apart and scatter across the floor, the bar broke, and I wound up with two of the ugliest bars of what looked like black pig snot. They sat on the bench for two plus years now. I was doing a bunch of forge welding and decided to give them another whirl. After the pus stopped oozing out of them (there is a glossy lump of slag that now graces the bottom of the welding forge), and the sparks stopped flying out of the forge door, it started to move more like a solid bar. I may do one more stack & weld pass.

 

It's 3/4" square and about 6-1/2" long, not counting the goobers on the ends.

Edited November 17, 2020 by Joshua States

[Alan Longmire]

Still right on track! 

[Gilbert McCann]

Joshua very cool, I have dreams of doing something similar one day. 

[Eric Dennis]

I'm impressed you were able to hammer it up. It looks like on the verge of cast iron. A little sand and an occasional handful of firescale thrown into the remelt will help control the carbon. 

[Joshua States]

3 hours ago, Eric Dennis said:

I'm impressed you were able to hammer it up. It looks like on the verge of cast iron. A little sand and an occasional handful of firescale thrown into the remelt will help control the carbon. 

This round of forging was done in the press with the squaring dies. Just a series of light squeezes.

The whole bottom of the heath is a layer of sand, about 1/2" thick. I don't see how adding fire scale would help reduce carbon in the steel. Fire scale is basically just carbon with some trace elements attached. How does adding more carbon into the hearth help?

[Joshua States]

7 hours ago, Alan Longmire said:

Still right on track! 

That made me chuckle. I went from not having a clue what I'm doing to looking good while doing it!

[Alan Longmire]

26 minutes ago, Joshua States said:

Fire scale is basically just carbon with some trace elements attached. How does adding more carbon into the hearth help?

 

Fire scale is Fe3O4.  Magnetite.  Adding that into the hearth will steal carbon from the steel when it gets into the reduction zone.  As your steel is passing the tuyere it's in oxidation, which steals carbon as well.  Once the semi-molten steel is safe from oxidation below the tuyere, if there's excess scale down there surprise! More oxygen to take carbon is lurking below, being released from its bond with iron in reduction.  Just when you thought it was safe to go back into the fire...

[Brian Dougherty]

5 minutes ago, Alan Longmire said:

 

Fire scale is Fe3O4.  Magnetite.  Adding that into the hearth will steal carbon from the steel when it gets into the reduction zone.  As your steel is passing the tuyere it's in oxidation, which steals carbon as well.  Once the semi-molten steel is safe from oxidation below the tuyere, if there's excess scale down there surprise! More oxygen to take carbon is lurking below, being released from its bond with iron in reduction.  Just when you thought it was safe to go back into the fire...

 

Does that also mean that the iron left behind as the scale reduces joins the bloom?

 

Edit to say:  Dang it, you have me asking smelting questions again...

Edited November 17, 2020 by Brian Dougherty

[Alan Longmire]

1 minute ago, Brian Dougherty said:

 

Does that also mean that the iron left behind as the scale reduces joins the bloom?

 

Edit to say:  Dang it, you have me asking smelting questions again...

 

All part of my nefarious plan, heh heh heh....  And yes, it does.  Alchemy!  Well, just chemistry, but still pretty cool.  

[Brian Dougherty]

Hmm, all this time I've been sweeping my forge scale out the door thinking how cool it will be for some future archeologist to discover it and speculate on the enormous ironworking operations that once existed in my neighborhood.  I'll have to start saving it now.

 

Nice work on the bar Joshua!

 

[Alan Longmire]

At the site of Pigeon Forge (there actually was a bloomery forge there!) the scale buildup was about five inches thick.  It had turned into a giant iron concretion not unlike concrete, in fact.  If the Old Mill Restaurant would let you dig it out, it'd be excellent ore. 

If you do save scale to smelt, let it rust first.  Fe2O3 is much easier to reduce than Fe3O4.