Lee Sauder

Hey everyone- Last month, we posted our bloomery smelting movie from 2012 on youtube. Now here's the one we made a few years later, about converting iron to steel by 4 different ancient methods. This one is a little more directly "how-to" than the bloomery movie. Some of these methods have subsequently been covered here in this community, some less so. But I think you'll all get a little something from it--- PS the preview picture may look like a colonoscopy, but it's a view of quenching from the bottom of the slack tub!

Back in 2011 and 2012, my friends and I made this movie about bloomery smelting, and sold 'em as DVD's. That format being now pretty obsolete, we've decided to put it on YouTube so you can see it for free, if you ain't seen it yet. IMHO, it's the best video on the topic! Hope you all enjoy it: https://www.youtube.com/watch?v=2M4FZn7xwcg Lee

Just a few quick notes, having browsed by here for the first time in a while. I see a lot of wrong statements in the above posts. I have spent many years working to understand the role of P in bloom iron. It has many beneficial properties, and of course has some negative ones when you get over say 0.5%.... just like carbon has negative properties when it's over 2%. It's just a matter of appropriate use of the appropriate alloy, with P or C. P does not make iron hot short, high P iron forges great. Alan, there must have been something else wrong with the iron you tried. It can make the iron cold short if the P is high enough, but it can also make it work harden by cold hammering, enough so to make a serviceable blade. P actually can make the iron softer and more malleable at forging temperatures, and can make forge welding easier. I'm just finishing up a paper on managing and exploiting phosphorus in bloom iron and I'll let y'all know when I publish it somehow.

Looks great, man!

Will- yes you can remelt it in your evenstad hearth, or a little aristotle size furnace, to reclaim any metal that has already been reduced, but couldn't get into a bloom. You just need a decent avenue to keep draining the slag away until you've got enough bloom there.

The iron crust is the stuff you're looking for! Don't worry about mixing it, just smelt it.

Antoine- I was just sitting down to reply to your email, and saw that you asked here as well- so I'll just answer here where it might help someone else too. I've got quite a few suggestions: Ore: As Jesus suggested, unless you've got decent ore you're going nowhere regardless of anything else. The bloomery process requires ore that is over 50% iron (70% iron oxide) That is the iron content of fayalite, and you only get the amount of iron above that as bloom. I'm not sure why you weren't able to get the dumpling crucible hot, unless you just got impatient. If you can get the outside white hot and keep it there, it's just a matter of time before the inside reaches that temperature. It usually takes me about 20 minutes to get heat to the inside, and I try to hold it at that heat for 15 or 20 minutes after that. You can also get an idea of how much iron vs sand is in your ore by grinding a given amount of ore, and dissolving out the iron oxide with muriatic acid, and measuring how much sand remains. This will take several days and repeated changes of the acid, until just the clean quartz remains. Furnace:The cinder block is a poor choice- you should at least line it with clay- but I bet it will fall to pieces once you get this furnace as hot as it should be. You want clay-based materials, not cement based materials. The iron pipe as a tuyere will rapidly burn up. You can cover it with good refractory clay, or make an all clay tuyere, or you can make a copper tuyere : https://www.youtube.com/watch?v=zjE6WFSWglc Air rate/ burn time: I'm guessing your 5 liter/min is a typo- that's off by a factor of about 200 from what you want. The 1:1 ore to charcoal rate is fine, but 1 lb in 10 minutes is way too slow. In a 10" round furnace, I would consume 4 lbs ore and 4 lbs charcoal every 10 minutes. The 10" square would be even faster. A good consumption target is .35 grams of charcoal per minute per square centimeter of furnace cross section. Total input: Even if everything was right, you'd get nothing with only 10 lbs of ore. That's not even enough to get the furnace hot and start building a slag bowl. You need to run at least 60 or 70 lbs of ore through a 10" round furnace to be effective. Good luck, hope that helps- Lee

So to really make this a retort, you need to funnel the off-gases into the burn chamber to fuel it. I find a retort that is uninsulated needs to have flame wrapping all the way around it- so an outer shell will help you here, to contain that flame. I also find long pieces take a lot longer, so chopping them short will help. Handiest thing in charcoal making is a little cheap infrared pyrometer- I don't find a good complete charring unless I've seen 600 to 700 degrees F on the exposed surfaces of my retort.

Yep, this was definitely one of the coolest experiences of my life to date! Some update: we returned for another season of work in Nov and Dec 2015, and we were able to confirm definitely that we had found the ancient mines. We had a geologist with us this time, and were able to get a good idea of how the ores were formed, and found unexploited site nearby. So we then smelted much more successfully after we found the proper ore. We also re-designed the bellows skins and were able to get about twice the air and better pressure. Then I built a somewhat smaller version of the furnace here at home, (with 4 tuyeres and powered blast calibrated to the pot bellows), and am starting to get pretty reasonable results. When i run this properly, I'm getting a sheet of really nice high carbon steel across the floor of the furnace, and this steel is much easier to work with than most other steel I've made direct in the bloomery. There is a paper in the publication pipeline somewhere....

Oh yes! A very important observation I forgot to mention! The outer chevron is shorter than the inner ones, because of the upset edges-- though the angle doesn't change. I think in this case that effect is particularly dramatic because I mushroomed those edges, but it would be something to look for in the historical blades (which I haven't yet). I think this effect would be lessened if the core was two layers, as they often are.

Ok, it's been a long sporadic trip, but I finally finished a piece by this method. I learned a lot. I have never tried to make a twisted core composite blade before... and the sculptural aspects of this thing ate up the blade aspects. Here's what I made: But now I'll talk about the blade and technical stuff. I made a lot of mistakes, meaning I learned alot-- all of them are preserved in this piece! But all those things might help us see if this matches up to historical stuff. Here's a close up of the blade and "fuller", and then I'll discuss the things I can think off at the moment, concentrating on the screw-ups. Mistake/Experiment #1- The core bars are 7 layers of single refined bloom (that is, bars pulled straight from the bloom.You can see that I have bad inclusions/weld failures in the core bars. I don't know if this was from inattention to my welding, excessively vigorous twisting, or that I should have refined the bars further. Probably all three, but I suspect it's mostly about inadequate refinement. Mistake/Experiment #2- You can see the pretty serious lines at the weld between edge steel and the core. In my old blacksmith training, I was taught to crown matching surfaces to squeeze out the slag. So the edge of the edge bar was mushroomed, rather than just upset with a flat top. I didn't really notice this problem with the mild steel tests, but when I used the same technique with the softer bloom iron, I overdid it. So though those wedls are nice and solid, the very edge at the surface never closed up. Mistake/Experiment #3- I did lots of fooling around with different ways to refine the fuller with just with hammer and anvil. In the course of that, I made some of those weld failures/slag inclusions in the core worse. I found the best way to refine the core right at the edge transition was with a ball end hammer, working right at that transition, with the opposite side lying flat on the anvil. Of course part of the reason I was trying to work on this was trying to close up the gap from mistake # 2. Another thing- I was doing this after the edge bars were welded on, but before I beveled them out to final form. One of the things I was trying to work out was the little wrinkles in the fuller that showed up during the welding, that Jeroen noted above. But after I screwed around with that long enough to mess up some of the welds, I then forged out the bevels. and I found that THE ACT OF FORGING OUT THE BEVELED EDGES TENDED TO STRETCH EVERYTHING OUT, AND PULL OUT MOST OF THE WRINKLES! Maybe I'm dreaming here, but I think I shouldn't have worried about refining the fuller any until I had forged the edge bevels. Anyway, that's about all I've got in me tonight-- but I should say I did heat treat and sharpen this thing. The only reason I think it's not battle-worthy is that I threaded the pommel on, but that's what the sculpture part demanded.

By hammering on the edge with a light hammer, that is, upsetting the edge.

Aahh, I could not see that in the photos. But if you can't get it to work as designed, the smolder can still be your ace in the hole.

To make charcoal in a kiln by direct smolder, you typically want the fire to travel against the draft. This way the wood that has burnt to charcoal will not burn further, as all the oxygen is depleted behind the smoldering fire front. So to use this design, I would take out the bottom grate, and light the fire at the chimney end. When the fire gets to the intake, you're done. It's probably going to take a long time- when I do a single vertical barrel it takes about 6 hrs.

I can't go myself, but If anyone near me (Lexington VA), or someone driving nearby (I-81) is going, I have some hammer dies that need to get up there to Rusty Griffin. If anyone is willing to take them, please PM me.

And the mystery tool seems to work pretty well as a scraper:

Two quick pics, because I should be doing something else... here's a detail of the pattern, and you can see that the outer twist ended up narrower than the centers from the upset, though the pattern didn't particularly seem to distort. The narrowing of that outer band of chevron might not be truly diagnostic, it might have more to do with my earlier screw-ups (which I haven't described yet), but still is of interest.

A little less than 2 lbs, it's a cast steel head I got from someone at an ABANA conference, but I put it on an extra handle I had that Tom he gave me with the big 5 1/2 pounder he made for me.

The heat treat came out great- it hardened very nicely in canola oil:

I did a test knife out of the edge steel last night, and am encouraged, so I will probably go for it. Either way, it will be a sculpture, question is whether it's a sculpture that holds an edge ;-)

So I bit off an awful lot at once, and whether I brave a heat treat or just proceed as sculpture is still up in the air. But I want to show you where I've got to. This is all forged to shape, now I'll pickle and start subtractive work. This is the first time I've ever tried a "fullered" blade, the first time I've ever done a twisted iron core and a steel edge. And I wanted to explore a shaped fuller instead of a straight one, by simply shaping the core. And the edge steel is direct bloomery steel from new smelting techinique, and the core is bloomery iron as well. I'll come back later to share the details of my mistakes, but for now I just want to show you how this worked out so far. The blade length is 360mm, it's 52mm wide at the wide spots, it's 5 to 6 mm thick at the peak of the bevel, and 3 mm thick in the center of the fuller.

Wrought is sometimes a little porous, especially if you've etched in Ferric Chloride, which eats the slag stringers as well as the iron. So it takes a little more neutralizing. I would just scrub it with dampened baking soda, (and I usually let it soak in soda solution for some time), then rinse, warm it enough to dry, and then hose it down with WD-40. Let that soak awhile, then clean and and oil or wax.

Hi Jeroen- I just saw this. A few additions to what's already been pointed out. If the iron is really high in phosphorus it will show the big grains and brittleness mentioned above. It will also be really buttery soft when hot, and often gets longitudinal cracks propogating from the corner of a square bar when you work it down small, which would show up as an X if you saw through the bar. But that's for very high P, the moderate phosphorus contents are a little more difficult to recognize. Besides the corrosion resistance, I think probably the most useful shop test would be cold hammering, to see how hard it gets. P iron gets much much harder by cold hammering than low P iron does, and makes a decent knife that way. I think that might be the most obvious thing for the ancient smith. Come to think of it, wow, maybe that's why the P iron got included in sword cores in the first place, could they have stiffened the core a bit by cold-hammering? Hmmmmm.

I've been wondering about this one too. Thijs van Manaker has a nice idea of a stirrup shaped bar over a wood block, with a wedge to tighten the workpiece down, so that could be used for twisting as well as filing. There are pictures on his Facebook page somewhere.

So this past Friday I worked on this again (i'll show pictures later, but I probably can't get back to it until this coming Friday)--- and interestingly enough, the one other tool I found helpful for refining the fuller was a ball pein 3 cm in diameter, that weighs 740 grams. A ball or bick underneath didn't help, it seemed. Since most of where I need to work was right at the edge where the core meets the edge bar, it was most stable lying flat on the anvil. Later- Lee