Catalan Smelting Furnace 2015

[DanielC]

Thought I would share our most recent smelt. This time using a smelter style seldom used in the last 100 years. Our furnace is a sizeable fraction of what they historically were.

130lb. Of locally mined by us, limonite ore was used, with 200lb. Of charcoal and around 40 gallons of water. 5 hours of slaving in the 90F sun, and constantly managing the fire we were left with 40lb of bloom steel.

This video was taken at the end of the smelt as we were birthing the bloom. It was in 2 separate chunks, almost as if by design by this furnace. It was too hot to compact like we usually do with our 12-14lb blooms we create in the round style furnace, so not too much hammering. Mark wielded the hammer and shovel, and I with the tongs.

 

Was quite literally the hottest heat source I've worked with to date.

 

Check my YouTube channel for all of our previous smelts of 2014.

 

https://www.youtube.com/watch?v=hYDHFhDlSx0

Edited June 1, 2015 by DanielC

[Frosty]

Daniel: The link says the video is unavailable. <sigh>

Frosty The Lucky.

[DanielC]

I got it fixed. I am using my phone and the new forums style make it hard to post video. Should work now.

[Frosty]

Yes it IS! That looks like a winter project to me. Is it always that much fight to get the bloom out of the furnace? I was cringing watching you shovel coals out and having to work over them like that. It made me think of a BBQ.

Thanks for posting the video. A guy learns a LOT watching experienced folk doing stuff I've never done.

I found myself doing the typical newbe thing and redesigning stuff as I watched. For example. Much longer handled tools and maybe a clam shovel would work better in such close quarters. Perhaps a hole next to the bloomery to rake the coals so I wouldn't have to work directly over a bed.

I'll stop that now. . . Well, talking about it anyway.

Thanks again, I may have to reevaluate my thoughts about trying it. Gotta see what the cohorts think.

Frosty The Lucky.

[DanielC]

yea the removal historically was at the top. The smelters would make a bloom or two a day, and allow another crew to come in and keep going. This style smelter never stopped making bloom. Considering this is scaled down and limited tooling for that kind if removal, the walls are taken down.

I would not recommend this style smelter your first go. It was probably successful due to the amount of knowledgable smelters that poured their heart and ideas, not to mention old books in catalan translated by none other than Jesvs Hernendez, into this smelter. It was ran a few weeks prior by 5 guys. This time just the two of us.

 

A round style furnace with a Lee Sauder style door and plinth is much more realistic for a first smelt. Check out my other vids of bloom extraction by following my username from that video to see.

[DanielC]

Also, it was a fight due to the size of the bloom and for the fact that the furnace design is for a top removal. Being near that much radiant heat and imagining being on top of it, you would agree that we are nowhere near as hardened as the old timers.

 

Mark's hand had blisters on them from the bloom compacting with welding gloves on!

 

Next year we are possibly going to do a full sized catalan. The inside should be 9 times larger than this one, resulting in blooms in the 200lb or more range, and probably 2000lb in charcoal.

Edited June 1, 2015 by DanielC

[Frosty]

I'll tip my cohorts to your videos. Unfortunately all we can do is watch and plan, Alaska is under a red flag fire danger alert right now, almost the whole state and last winter it hardly dropped below orange. It's been really dry for almost two solid years now.

I suppose we could set up on a river sand bar and burn coal but I'm too fat and lazy to go mine a pickup load right now. <sigh> I might see how much ore we could collect with fishing magnets in the Matanuska or Knik River. They carry a huge silt load from the glacier. Maybe pick up a metal detector and look for bog iron.

Okay, you replied while I was writing.

One of the redesigns I made in my head watching you try to get the bloom out was an hour glass shaped furnace chamber so it was larger than the bloom. Then have a guy on the far side with a ram. As soon as it moved it would come free easier. A long handled clam shovel would slip under the bloom far more easily than the spade you were using.

I know I'd be doing a lot of research before seriously considering giving it a try.

Frosty The Lucky.

Edited June 1, 2015 by Frosty

[DanielC]

Believe it or not, but the furnace design can play a major role in the end product. The idea was to build it historically accurate to what they used in Catalan. Strive to get it as close as possible to original design before we were to make major changes. This particular design has allowed steel to be formed rather than Iron. It even plays with the CO levels and not allowing the tuyure to blast away all the carbon. Knowing when and how much slag to tap plays a key role in the end result as well, as a surplus in slag will keep the furnace hotter, yet protect the bloom from the air blast and decarb.

Plus it is expensive to experiment with drastic changes, keep that in mind. If it doesn't work you have lost that ore and however much charcoal you invested, all of this not including the days and days of prep.

If you are going after magnetite, I suggest triple magnet cleaning it, and mixing with water and corn meal, then baked and broken into chunks. This will allow you to control the rate of drop. Will also have to run it slightly hotter to avoid it freezing in the shaft.

[Frosty]

I understand furnace design effects things but not well enough to know how or what. Rereading your post I see that an hourglass shape wouldn't apply to removing the bloom from the top. And it doesn't take much size change to make removing plugs easy or impossible, a nail header or forge grate for example. Just a slight widening makes it easy to knock clinker out of the grate or pop nails out of the header.

If the plan was to remove the bloom the way you did in this video I'd make the center parallel walled and the next brick out spread maybe 1"-2". As soon as the bloom moved it should just slide or roll out.

I'd have to do a lot more reading before I even got a handle on what you're saying about slag, CO, etc. I have a basic handle on shielding the iron, how CO provides easily accessible carbon to the bloom, etc. but don't know enough to be able to apply it even in conversation.

For example I know the basic difference between a bloomery and a puddling furnace and the bare basics of the differences in process. Talk details at me though and I'm filing them as flags for future reading.

I'm not suggesting you stop though, I'm sponging <grin> up everything you write.

Oh, you might suggest to Mark he NOT use a sledge hammer to consolidate the bloom. A green block for the "anvil" and a spring pole green log treadle hammer worked well for the ancient Norse smiths. A slight cup in the anvil block and foot loops in ropes for the treadle and two men guiding and stomping the hammer. From pictures in a book I read decades ago but don't recall the author or title. Perhaps Thomas has a copy on the shelf where ever he is at the moment.

Frosty The Lucky.

Edited June 1, 2015 by Frosty

[DanielC]

Yea it can get complicated quickly. Though we find it more art than science.

Always open for suggestions though. Spreading the information freely and pinging ideas off one another is how smelters have got this far. A lost art, rediscovered and exploited with present day equipment. Much the same as blacksmithing in general, just much much more niche and harder to acquire material.

My YouTube coupled with Mark's Picasa pages should get you going easily enough. I can link his Picasa page when I find it after this post.

Also a wooden mallet would be fun, but it can be compacted without loss in chunks or cracking with controlled taps with a light sledge. Mark has conducted and experimented with well over 100 smelts using a sledge for compaction. It all in how you tap it. Plus it's only a 6# sledge, very light, and heavy enough to knock the outer cooled layer of slag and wall. Though sometimes it really does take a wooden mallet to keep it from disentigrating due to the area you are hitting with.

At the last Fire and Brimstone at the Baltimore Knife and Sword Co., we conducted a smelt, and the bloom had what we suspect as either copper inclusion or an introduction of phosphorous from the recycled wall we used and the bloom wanted to crack at compaction no matter how gently we squished it. 3 of us, myself included were softly striking on that compaction, and considering the film crew was there, we will probably be on a Man at Arms episode.

Edited June 1, 2015 by DanielC

[DanielC]

Now that I thibk about it, some of our smelting buddies in Europe use wooden mallet exclusively.

Also here is Mark's Picasa pages on smelting. All written info can be found there for a successful smelt, coupled with my YouTube.

https://picasaweb.google.com/m/viewer#albumlist/106800196895572422821

Edited June 1, 2015 by DanielC

[Frosty]

Exactly my point: Mark has done this more than 100 times and I've never done more than read and think about it. . . Well, watch a few videos and comment on some of the things I saw you fighting with in this video.

Do you know how many times I've I've called new comers on doing this very thing? It's not necessarily a bad thing so long as a person is aware of their lack of real world knowledge and experience. Were I to go out to a sand bar and try building and running a bloom I'd be a fool of the first stripe.

On the other hand I like hearing ideas from folk that are unpolluted by knowledge. I've gotten great ideas from 8yr. olds at demos. Wild brainstorm speculation filtered through the eyes of experience can be a good thing.

All I'm getting from the Picasa link is a requirement to log on or open an account.

Frosty The Lucky.

[DanielC]

Weird, I will try to fix it when I get home in front of my comp.

If you plan on smelting, you don't want to miss his Picasa pages.

Also, I have helped with around 10-12 smelts now, and still consider myself wet behind the ears. I finally got my clays from a pottery place to start making my stack at my house though, so it won't be long before I conduct weekly smelts at my place. I have a quarter ton of ore at my house as it is. It won't be long before we go mining again though.

[Frosty]

I don't really plan on doing a smelt unless someone else wants to do a LOT of the work. However if one of my cohorts or just someone around here wants to give it a slash I'll be happy to . . .

Uh, what kind of clays? . . . Uh, clays? What are clays for?

Just because I REALLY enjoyed your video and like brainstorming what little I can see and understand doesn't mean  I . . . Uh . . . Oh CRAP I might be hooked!!!

Curse YOU!

Frosty The Lucky.

[DanielC]

We use a ratio of EPK Kaolin to Ball Clay, then mix with a ratio of peat and sand. EDITED for correctness.

I've also seen dung and straw on one of our Facebook groups.

 

Smelting IS enjoyable.

Edited June 1, 2015 by DanielC

[Frosty]

Uh, Kaolin IS an aluminum silicate clay. Al₂Si₂O₅(OH)₄ (Gotta love the internet )

Pat, one of out club members is primarily a bronze caster, and runs the iron pours around here and he uses bentonite for plugging and patching the cupola melter and in his green sand and resin bonded casting sands.

He uses a commercially available castable refractory for the liner in the cupola and such. I used a different "3,500f" castable refractory in my new forge. If we can access good high end refractories in Alaska you shouldn't have to make home brews in NC.

The erosion in the cupola is primarily from thermal cycling and mechanical from chipping slag that sticks to it.

Frosty The Lucky.

[DanielC]

Perhaps I read it wrong or there is a different type? I would have to consult some of the other guys about that, because that is part of the whole process. Keeping impurities out =)

 

We have castable refractories like that, but you actually want the walls to melt somewhat towards the bottom.

The actual composition of the furnace is a little muddy in my mind as I haven't yet had to keep up with my own. I've helped build a furnace with him from the ground up, but to my understanding these mixtures are widely used by Lee Sauder and a slew of other big smelters. Wish a few of them were members here to chime in!

[DanielC]

Yea I just looked it up to make sure and it's alumina content is high. Which throws that statement out of the door. Makes one wonder why regular fire clay wouldn't work in substitution. It's what I was told! Lol.

 

Even 10 smelts in and am still learning. It's a long process to reach the level of those guys

Edited June 1, 2015 by DanielC

[Frosty]

If the guys who do this successfully use that recipe then it's good. I've just been trying to get an affordable version of kiln wash to work and been looking into something other than kaolin to mix with zircopax. ITC-100 uses kaolin and it doesn't fuse like I thought it did.

Anyway, just because I recalled kaolin is an al/si clay and googled it doesn't mean it's significant in your application. What the local caster uses in his cupola is what works for him.

I'm too far out of my field for any specific opinion of mine to mean much. So, don't get too excited about what I THINK, my opinion is unpolluted by knowledge.

Frosty The Lucky.

[DanielC]

Reading a little further, I would use this mixture because Lee Sauder says too, lol. Though I am sure there are more ways to skin a cat. If it adfordable, I don't see why not. I saw that tatara smelt with Ric Furrer using mostly fire brick.

[Frosty]

Ric used brick for the wootze/Viking(?) melter taped for discovery and PBS too. If anyone up here does it successfully I'm pretty sure THAT'S the way to do it. I may tinker with things that work but I don't believe in fixing things that ain't broke.

Frosty The Lucky.

[DanielC]

Yea, the round style furnace as seen in my vids are really good furnaces to use for success. Plus the style has been used and proven a lot in the present.

[ianinsa]

Looks like fun and a whole heap of charcoal.  Nice retort you got there , I put a grid halfway (flat/horizontal) across the 'feed' tube and then strips of old chip/particle/shutter board  feed in nicely and 'extra' air goes in underneath.

[Frosty]

I watched the, "War of the Wings 2014 iron smelt," video and have a question. Is there a reason he spent so much time breaking the bloom out of the furnace?

Breaking it out of the Catalan furnace evidently was because normally he would take it from the top rather than breaking the end out.

Thanks,

Frosty The Lucky.

[DanielC]

That one was being a bugger because it was a new stack. New stacks are still rough on the inside, so the bloom like to adhere somewhat to the walls. The cylindrical design allows the bloom to suspend itself from the shaft once the bottom door is removed and the ash and charcoal fines are removed.

 

A furnace after several runs starts to glassify on the inside, creating a smooth wall. If you watch some of the others you can tell the ease.

 

Honestly though that's about as easy as it gets. Prior to that door design by Lee Sauder, people were knocking their stacks down every single time and extracting the bloom. With the plinth and door set-up, we are able to keep using the same stack over and over. 10 runs is the record I think at Marks.