Forbidden Answers to Newbie questions of uncertain merit

[ThomasPowers]

Forge welding different types of steel is sort of the definition of pattern welded steel...  Now throw in Ti and things start getting weird.  Might stroll through Tylecote's Solid Phase Welding of Metals"  and remember that explosive welding is considered a solid phase weld...

Taconite, especially the preprocessed balls of it is not a great ore to try to use IMNSHO; I much prefer magnetite.  (the balls will generally need to be crushed and contain fluxing for a blast furnace that generally causes you to get iron soup instead of a bloom when we have used them.  Having your bloom splash while you are trying to consolidate it is a sad sad thing.)   Also "The Mastery and Uses of Fire in Antiquity" Rehder, contains plans for a "foolproof" bloomery in the appendixes.  I have not tried it as we do Y1K smelting.

[Frosty]

Thomas: Do you have drawings or diagrams of the bloomery you use? Photos are nice but nothing beats a dimensioned drawing and diagrams to build with.

Frosty The Lucky.

[ThomasPowers]

squamous centripetal Arghs! 

[ThomasPowers]

Well it was generally 2/3 to 3/4 Hugins tall and the bore was formed around a 5 gallon bucket that was moved up as the cob was formed around it.  Out cob recipe was: 3 shovelfuls of sandy silty dirt, two head sized bundles of chopped straw and one shovelful of dried powdered clay add just enough water to barely make it workable and mix by hand.  We generally added in a fire brick door so we didn't have to knock it over to get the bloom out but we've done it the old way too.  (Hugin was a short friend of ours...)

After forming it we then would let it sit overnight with the "door" open and  with a slow fire in it to dry it out; then start building up the fire next day to finish drying it out and start a charcoal pile in it.  When the walls started to glow then it was seal up the door, hook up the air supply, (we've done it with bellows; but a hand crank is MUCH easier!!!!) and load the bore with charcoal and start blowing.  When the WHOOSH happens and flame leap into the sky over it then we start adding ore and charcoal 1:2 by weight and keep the cranking after up to 6 hours we would then let it coast and burn down till we recovered enough to go hunt for a bloom.  we were getting 15# blooms with this method---done on a campout every year for over a decade.

[Frosty]

Thanks Thomas, I think this sounds a LOT more doable than a tatara and a perfect camp out project for a river bar a long way from the forest. I'm a little jumpy about forest fires right now. A hand crank blower like a Champ 400? I've been picking up 12v "inflate all" blowers when I see them at yard sales for years now.

Now I'm wondering how much iron dust in is one of our glacial rivers. They carry frighteningly large quantities of material, I'll bet they pack a LOT of black sand. Common wisdom for rafting the Matanuska, Knik, Susitna, Talkeetna (local) rivers is if you go in the water get OUT of your clothes fast Fast FAST or the river WILL fill them with sand and silt and sink you floatation or not.

Anyway, I'll bet at least one of them carry a LOT of black sand and it'd sure be a LOT easier than driving to Iron Mountain just outside Hoona on the Haines highway to pick up magnetite.

I wonder which one of my eager to try it cohorts I could talk into making half a ton of charcoal?

Frosty The Lucky.

[DanielC]

A 36-38" tall furnace that is 8" in diameter should only consume about 120# of charcoal and produce a bloomery recovery rate of about 25-40%, depending on the ore used. Usually on that size, using 40-60# of ore, we get 12-16# blooms. Our magnetite after magnetically cleaning is still sitting near 55-60% FeO3, Our motherload lifetime supply of limonite ores test around 90% or more. They usually make the best iron I have ever worked with.

A tatara is in the plans in my neck of the woods, but it must be accepted that a Tatara, even a very scaled down version is expensive to run and may not result it what you desire. Adding a greater deal of variables (Such as several sources of air supply) can complicate things really quickly.

 

Even increasing the diameter of a round furnace to 10-12" can easily double the charcoal consumption, for a marginally larger bloom in my experience.

Our next smelt we plan on running a team of 5-6 guys to run bellows as this will be a smelt for the local SCA.

[ThomasPowers]

I was a bellows thrall for Flaxey and Steve's bloomery at Pennsic for a decade.

[DanielC]

Awesome. I am not part of the SCA, but a guest with Baron Mark Green for the smelt and partying tgat follows.

[ThomasPowers]

I joined the SCA in the fall of 1978; never fought though.  Taking a couple of forges to an event next week in Colorado..."Forging in Funny Clothes"  a specialty of mine...

[DanielC]

Yea, Mark was knighted there long ago, and has always been a fierce fighter. Still fighting even. The other reason I go. To watch the fighting! Way cool.

 

On the off days we plan on running an Evenstad hearth, and carborize several pounds of bloom that doesn't want to play nice.

[ThomasPowers]

I once was carburizing some wrought iron in a piece of pipe full of powdered charcoal with the ends flattened and bent over.  I put it in my gas forge along the "cool" side and let it cook wile I was doing my normal smithing.  Kept track of the hours and when I took it out I found that 20 hours at heat was TOO LONG as I had essentially made it into cast iron.

I was also assistant to Ric Furrer at Quad-State one year when he did his 3 ways of making steel demo and was again on the bellows as he was running wrought iron scrap through the forge carburizing it for welding into oroshigane.  (I also was assistant to Al Pendray when he did a demo for Quad-State---best seat in the house and the possibility of asking specific detailed questions to the experts...)

[DanielC]

Mark has carburized full nearly done Iron Age Germanic single edged swords that way. His ingredients were crushed charcoal and another ingredient that I cannot recall that was suggested from some of our European smelter friends in Germany. It worked really well, though there were a few casualties in the learning curve.

 

If you read the Evanstad papers, the process we will be using involves a shallow hearth, and in a process similar to orishigane, the bloom is basically melted, and depending on tuyure height from the floor, will determine how much carbon is in the end product. Along with seperating most of the slag. Very effective and a little bit more control than orishigane, and especially MORE than an aristotle.

[ThomasPowers]

Did you read the Williamsburg smelting attempts with a Catalan forge?  I don't know id the Ironmaster's Conference at Athens OH, USA,  that Flaxy and Steve presented "10 years of short stack scandanavian bloomeries" has been published even though it's been 15 years or so...

[DanielC]

I havent, but wouldn't be surprised if Mark had. We have ran a Catalan twice now, and recently decided to bring it back to life, possibly beginning of next year after we run a tatara this Winter. Jesvs Hernendez helped greatly with the design and running of it. Jesvs is from Spain, and translated some very detailed books from Catalina that really helped with some of the specifics.

Lee Sauder has been running a Catalan ad of late as well with equal success as our own.

We had thought about setting up a full size catalan by scaling it up, we estimate a 200-300# bloom. A little large to handle, though they did it back in the day 24/7 non-stop.

Take a gander here at these writings. The Evanstad papers:

http://www.tf.uni-kiel.de/matwis/amat/def_en/articles/ancient_carburisation/ancient_carburisation.html

[ThomasPowers]

Have your read "The Cementation of Iron and Steel" Giolitti; ?   Lots of fun including discussions of if CO is necessary---experiments done in a vacuum or in an inert gas flushed system;  cementation using diamonds as carbon donors, etc  Great fun in an extremely dry technical work.

[Charlotte]

http://theconversation.com/uk/environment an article on co2 scrubbing in iron/steel production is in the current issue may be of interest to you

[DanielC]

Sounds interesting, though a little high tech for our iron age projects. Will talk to Mark if he has.

[ThomasPowers]

OK how about "The Celtic Sword" Radomir Pleiner?

[DanielC]

Mark owns that one and I have skimmed through it. Haven't had time for educational reading of late.

[ThomasPowers]

Baching it I get to read during meals and in the can.  Both frowned upon when visiting my wife...  Just finished "Hunting Weapons", Blackmore  dealing with their history and evolution even including, brief, sections on boomerangs as well as the more usual spears, crossbows, air guns, ... 

[DanielC]

Heres an analysis of our awesome limonite ore that smelts like driving a cadillac. I think this sample was a mix we make of varying strata, which seems to yield the best composition.

[John McPherson]

Getting to be a fly on the wall at the last smelt was a treat. (Although the wall was getting hot enough that the vinyl siding was starting to melt....) 

I want to thank Mark and Daniel for the invitation, and the free sharing of knowledge. And Mark's wife for a great lunch!

I hope to be able to set up my own small experiments in the near future, probably starting with a small Aristotle furnace.