Andrew W

Alan recommended the burners from anvilfire.com ( https://www.anvilfire.com/21centbs/products/P-75/ ) the last time this thread came up, and I have only good things to say about them. They've made forge welding effortless, and they're relatively inexpensive. I lined my forge with 2" of inswool and 1/4" of kastolite, with some extra bubble alumina on the floor since I tend to throw a lot of corrosive things into my forge (lots of borax and slag from bloomery iron). I bought all these from hightemptools.com ; not the absolute cheapest supplier, but they had everything I wanted in one place and I didn't have to worry about accidentally buying the wrong product.

Thanks! It's 475mm long and 286g.

I recently finished a reproduction of an Anglo-Saxon spearhead, made from bloomery iron and hearth steel. The spearhead is based on an original from Flixton (Suffolk, UK), and dates to the sixth century. For my raw material, I used a mix of bloomery iron and hearth steel. Mark Green gave me the bloomery iron last winter, and I made the hearth steel from some bloomery iron I bought from Lee Sauder. I took a lot of progress pictures--enjoy! The finished spearhead. The original, from Flixton grave 37. It's a Swanton type H3, if you're a typology geek. This is the bloomery iron Mark Green gave me, which he smelted himself from NC ore. It's been through his press once to shape it into a bar, but otherwise it's completely unprocessed. Folding Mark's iron a few times to homogenize it. Welding the third fold. This is bloomery iron that I bought from Lee Sauder. It's less processed than Mark's--basically just chopped off the bloom and flattened a little bit. I broke it up into smaller chunks which I ran through a charcoal hearth to add carbon. The charcoal hearth--adding carbon to the bloomery iron, making steel. This is what I pulled out of the charcoal hearth once it had cooled. Lots of carbon now! Hearth steel in the center, bloomery iron on the outsides. This san mai-type construction was pretty common on the longer type H3 spearheads that have been analyzed in a lab, so I chose to make my reproduction this way. The bars are welded together, and I'm drawing them out into a billet. Roughed out the blade shape, now I'm starting the socket. Anglo-Saxon spearheads have open split sockets. I'm starting the cleft with a chisel. Fanning out the socket. The wrought bloomery iron will split if I try to fan the bottom of the base too wide, so I've left it round for now. I'll cut it flat later (some originals, including the one I'm copying, have flat bases--others left the base round). Just about ready to fold over. I don't bother with a mandrel for this step--carefully hammering works just fine for me. The socket's taking shape! After the first rough grind. I did not quench harden this spearhead. Instead, I let it rapidly air cool. Most of the spearheads from this period that we've analyzed in a lab had a pearlitic rather than martensitic structure. Even unquenched like this, the steel adds a lot of hardness to the blade compared to plain bloomery iron. All cleaned up! Lots of slag and a bit of trapped scale--some of the things that make bloomery iron such a beautiful mess to play with. And finally, a comparison of my reproduction to the original. Turned out alright.

I do it outside, preferably somewhere with a breeze! But no, it never goes away.

It’s one of those sensations that you never forget... Incidentally, I finished this up in a new forge with the Black Beauty burners you recommended to me. They weld bloom effortlessly. Thank you for putting them on my radar.

A copy of 6th century English archaeological finds, staring from ore. The finished blade. Heterogeneous bloomery steel blade, horn handle (drilled + burned in hidden tang). A closeup of the other side of the blade. This billet is only 18 layers--I wanted to maintain the messy metallurgy we see on so many of the originals. I smelted the iron back in March. Unlike my first half-successful try, this smelt went well. I got a nice, steely 14lb bloom. (This photo’s from the preheat, just before I switched from wood to charcoal.) Obligatory photo of the slag tap, near the end of the smelt. The 14lb bloom of new iron, birthed (via c-section) from the side of the furnace. The bloom was steely already, but I decided to do a hearth melt with some of the scraps that fluffed off it while I was compacting the main part. I tossed those scraps into a charcoal hearth, and got a nice lump of much more consolidated steel from it. The smaller bloom from the hearth melt, and the billet into which I forged 1/2 of it. I forged that billet into a blade! Polished and etched. I love the textures of bloomery steel.

Thanks! Two it is. Is there a particular refractory formula that holds up to borax and bloomery slag? I was leaning toward brick for easy of replacement, but am happy to adjust if that's a bad plan. (Either way, I'm planning on laying down a sacrificial kiln shelf.)

If I could piggyback off this (helpful!) discussion-- I'm in the process of building a propane forge with a flat hard brick base, arched top lined with 2" of wool + refractory and reflective coating, volume of about 330 in³. I had been planning on getting a t-rex burner, but I hadn't seen the black beauty burners before. I want to do a lot of welding. It sounds like I would be fine getting the BB burner instead of the t-rex? Can I get just one, or should I buy two to be sure welding is easy? I don't want to waste fuel, but I also don't want to have to fight to get the heat I'll need. [Edit: I see, in the thread you just linked Alan, that Brian used two for about 475in³?]

Next, I took all the fluff that came off these three smelts and ran it through a hearth. This is about 3lb of scraps. Some of it's cutoffs from the knives I made from smelt #1, some of it's cast iron, and the rest is crumbly bits that flaked off the bloom while we were compacting it. I tossed it all into the hearth. And I got a lovely lump of steel! That's half the steel right after I folded it to 18 layers.

My second and third tries went well! Smelt #2 gave me a nice big bloom! So I fired up the furnace again the next day. And made another :). We managed to hammer this one thinner and cut it in half. 14lb and 8lb, including the fluff. I used less ore on the second smelt, so I'm happy with the lower yield. The copper tuyere made the difference. No airflow problems, no rogue hot spots, and the blooms formed exactly where they were supposed to. The second, smaller bloom is a bit dry. I turned my back for 5 minutes and the tuyere backed up. I tapped the slag and saved it in time, but I think I overcompensated. My goal is to strike a better balance on attempt #4.

What kind of firebrick are you using? I've found that some of the cheap, thin ones from Amazon aren't good to forgewelding heats (despite any claims on their packaging). A proper hard brick should hold up better.

Here are three of them! Horn handles, as per the early Anglo-Saxon period originals on which they're based.

The steel I made in this smelt has worked up very nicely. (The welded-on edge of the longest blade is hearth steel I made from scrap metal from the shop floor—everything else is bloomery steel from this smelt).

Checked the mail tonight and found this waiting for me. Ready for round 2

It's in Malim, T. and Hines, J., (1998). The Anglo-Saxon cemetery at Edix Hill (Barrington A), Cambridgeshire: excavations 1989--1991 and a summary catalogue of material from 19th century interventions. This has now been put online as a (legal) pdf, which you can download here: https://archaeologydataservice.ac.uk/library/browse/issue.xhtml?recordId=1075286&recordType=MonographSeries The metallurgy analysis of the spearheads starts on page 250. There are some great line drawings of the blade cross-sections, and a detailed discussion.