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New furnace: Bigger bloom.


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Yes Chris. By "cement" I mean portland.

 

The mortar between bricks is furnace cement.

 

Niko, I am not sure what would happen if I made the lower part of the furnace bigger. I would think that if we did that then I would go for an overall rectangular design and do without the cylindrical part altogether. Basically making something like the Shimane tatara.

 

Now, that is a thought. I would love to give that kind of huge rectangular tatara a try but it will require cooperation from many people. That would not be something that Walter and I could built together and run in one morning. It will require a certain infrastructure. First of all a location big enough and where a bunch of people will be willing to get together and help. Making bricks, chopping charcoal, providing enough ore and it would probably run for 2 days non-stop. Any takers?

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Any takers?

 

 

If I was closer I would be all over this Jesus, but I am financially challenged at the moment. Maybe next year if you want to offer that again, I sure would love to be part of one of yours and Walter's smelts.

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Ohhh, you're tempting me man. I ended up missing Bowie's this year and I'm itching to make more steel. Part of me wants to go it alone, but another part of me wants to do something big like this. If you can find a place (I doubt my suburban D.C. backyard is sufficient) and a time, I'd certainly lobby the family budget for it hard. I'm in make-knives-for-shop-money-mode right now, so perhaps time is the only barrier. Got enough ore, or do we need one of our northern bretheren to bring a load down? Or should we seek to use some local Appalachian stuff instead?

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Don't get me wrong. I am not thinking about next week or next month. This will take time to prepare and will need the collaboration of many people who I'm sure have other priorities in their list besides making steel. Some coordination will be needed and what I had in mind was next Spring to allow for enough time to gather all the materials and volunteers. It would be great if the Mid-West gang could join in. After all they have the "good" ore and the brains. ;) Maybe Harley's could be a meeting point. Just tossing ideas...

Edited by Jesus Hernandez
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Remember that magnetite I had at Harley's? There's only a mountain of it a few miles down the road from me... ;) Where the crushing mill sat there's at least an acre of black sand, too. :ph34r:

 

I think you should build it in Harley's front yard the week before the hammerin, that way it'd be ready to roll by the time all the "helpers" showed up. :lol:

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I'm game. We have several acres on the state park, 3 power hammers, 4 screw press and plenty of camping space. Also local motel/hotels for those (like me ) that hate bad weather sleeping.

 

We purchased the church building next to our house for a studio and it is complete with a comercial kitchen, bathrooms and parking lot.

 

Deker and I have already been talking about this for late winter early spring. It just cant get too late into the spring as we become too busy with the show season. The biggest issue is he and I are both crazy busy and can't do everything without some organizing help.

 

You can check the church website and it lists accomodations http://www.fireandbrimstone.com

 

It lists shop tools at the church for class only, our sword shop is separate....

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I'm sure we can consider adding in a big bronze pour at the same time. We pour as often as possible anyway for sword parts.

 

Rain is the only limiting factor as we now melt outside.

 

mpour1a.JPG

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Allright, in the interest of generating enthusiasm, I finally cut down the footage I have of the 2006 smelt at Harley's and put it on YouTube. Runs 9 minutes (originally 40+...) and hits the highlights.

 

Edited by Christopher Price
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A couple of notes, since I haven't weighed in yet.

 

First, the disappointing aspect of this smelt. I welded up a chunk of the bloom this weekend, folded it into a 16,000 layer billet and it turned out to be hot short. Without a lab analysis it will be unclear what the cause is. Sulphur would be the obvious culprit...though we'd have to pin down the source. I hope, however, that we simply over-shot on our carbon content. Even after all that time at welding heat, the billet still sparked like crazy. Further investigation to follow.

 

Second, Chris mentioned suburban backyards being suboptimal locations for smelting. True. But, for those of you who are thinking about trying this, Jesus and I have both been doing our smelts in suburban backyards -- thus far without being arrested or attacked by mobs of angry neighbors. Helps to have friendly neighbors...but the footprint is quite small and there's less smoke than with a barbecue grill, so the freaky neighbor factor is arguably lower for smelting than for bladesmithing.

 

Third, doing a smelt in Maryland sounds like a great idea to me.

 

A final general note here: if you want to do smelting, be prepared to be in it for the long haul. It's not just a notion. Jesus and I have each staged around ten smelts apiece and we have yet to do one that came out dead on the money. We've gotten workable steel from many of them, but we're still trying to dial in that perfect jewel steel. You have to get comfortable with interesting and instructive failure. There are a ton of variables involved here. You can't isolate all of them independently (unless you have the budget of the Manhattan Project), so you have to kind of pick one or two to adjust each time and hope you're moving in the right general direction.

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A final general note here: if you want to do smelting, be prepared to be in it for the long haul. It's not just a notion. Jesus and I have each staged around ten smelts apiece and we have yet to do one that came out dead on the money. We've gotten workable steel from many of them, but we're still trying to dial in that perfect jewel steel. You have to get comfortable with interesting and instructive failure. There are a ton of variables involved here. You can't isolate all of them independently (unless you have the budget of the Manhattan Project), so you have to kind of pick one or two to adjust each time and hope you're moving in the right general direction.

 

 

I wholeheartedly support Walter's comment here. There have been discussions in this part of the woods about having a largish smelt sometime. Having a mixture of ores won't be much of a problem as long as we can get them fined down enough after roasting, or magnetically culled to remove the sand. Building a stack won't be a problem either. I have a place in mind, whose owner has exactly the same idea, living in SW Wisconsin.

 

IF, this can be coordinated successfully, we a soup to nuts conference is quite possible. The plus side will be "professional" opinions about the results. I'll start asking some discrete questions to see who we can persuade to attend. But, I'd also like to see international invitations go out. There are a lot of folks who have been working this problem independently and I think it would be pretty cool to pool resources, knowledge and talent to celebrate this interest.

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Second, Chris mentioned suburban backyards being suboptimal locations for smelting. True. But, for those of you who are thinking about trying this, Jesus and I have both been doing our smelts in suburban backyards -- thus far without being arrested or attacked by mobs of angry neighbors. Helps to have friendly neighbors...but the footprint is quite small and there's less smoke than with a barbecue grill, so the freaky neighbor factor is arguably lower for smelting than for bladesmithing.

 

Third, doing a smelt in Maryland sounds like a great idea to me.

We have the advantage here even though we really arent out in the sticks to being bordered on one side by the State Park, 2 sides by a quarry then the third side having only 3 neighbors. 1 is a excavator, 1 is a demolition equiptment operator and one is a acupuncturist, then CSX- Old Main line, the river, then state park again... we are 30 mins from DC, 15 min from baltimore and 20 mins from an international airport (BWI)

 

The acupuncturist is talking about moving, any takers? I could use a nice blacksmith neighbor!

 

It might be nice to have a couple additional demonstrators to show some powerhammer work as it sounds like the smelt is all about babysitting and feeding the fire once its started

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Jesus and Walter, we probably all owe you an apology for hijacking your thread.

 

So, have you tried consolidating any other parts of the bloom yet? Are they also hot-short like the first piece? Will it be at all usable without mixing with low-carbon stuff, or do you think you'll be able to salvage what you've got?

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We are working on it. Walter may be able to get an analysis of the steel. The analysis will really be very helpful in knowing what we are dealing with. I need to try to consolidate my parts of the bloom but like I said earlier they are too big for my gas forge so I will have to build a charcoal forge to reduce the size enough. We'll keep you posted.

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The acupuncturist is talking about moving, any takers? I could use a nice blacksmith neighbor!

 

Which place? Mark is looking for a new house with space for a decent shop...

 

It might be nice to have a couple additional demonstrators to show some powerhammer work as it sounds like the smelt is all about babysitting and feeding the fire once its started

 

We could always make some damascus while we wait. You'd need to get the air hammer vertical and the Beaudry firmly planted though :)

 

I'm game. Keep me posted on plans.

 

-d

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Which place? Mark is looking for a new house with space for a decent shop...

We could always make some damascus while we wait. You'd need to get the air hammer vertical and the Beaudry firmly planted though :)

 

I'm game. Keep me posted on plans.

 

-d

 

O trust me you will know everything that is going on :D I already volunteered you

 

Its not really what Mark is looking for as he wanted bigger garage space for bulk cars.... Second from the river... Course it actually WAS a blacksmiths shop before it was renovated.

 

Not exactly hijacking as you will know soon enough! but perhaps that is for another whole thread.

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Hi,

Walter or Jesus,

is it possible to have picture of the cold bloom please? If you don't mind, what is the interior diameter of the furnace?

 

Thank you very much, this is extremely interesting!!

 

Antoine

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Jesus, Walter-

 

That's a mighty lovely bloom ya got there!

 

If I could pitch in a few comments....

 

Re: Furnace Construction- I'm not sure a thicker brick is necessarily what you want in order to run the smelt longer. In my experience, the furnace wall above the tuyere melts back to where it needs to be to beso it can shed enough heat that it won't melt any more. I bet that wall would now run indefinitely without further melting, if the furnace was still intact.

 

When we run a (clay) furnace, we often get some wall melting on the first smelt, then the following smelts it stops melting, and the yield goes up. If you build the area around the tuyere thinner, you'll minimize the melting.

 

Of course this is all predicated on building a furnace you can reuse, that is, getting the bloom out without taking the furnace apart.

 

I suspect the main reason for the destruction of the tatara furnace is that it's the easiest way to deal with a bloom of several hundred or even several thousand pounds.

 

Re: Refractories- With clay furnaces, Skip and I have had the best luck with kaolin mixed with charcoal fines. I guess this is pretty much the same as using straw, but easier to deal with. Every time you recycle the clay, it will work better. Best luck so far with the kaolin called EPK.

 

My current "permanent" furnace is built of steel lined with about 3/4" of rammable (Harbison Walker Plastech 85), and she totally rocks with no wall erosion.

 

Anyway, I guess I'm trying to say the whole furnace design thing is about balancing insulation (to save fuel) and conduction (to save the furnace wall), all variable according to materials.

 

That's a lot of blather for a forum, I guess. I don't mean to be a jerky pontificator, I just got excited to see someone really doing it. Way to go-

 

Lee

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Antoine,

 

These are pictures of two of the chunks from the bloom from different angles.

 

IMG_1786.jpg

 

IMG_1790.jpg

 

IMG_1791.jpg

 

Lee,

 

I appreciate your comments. I have had the same experience with this time of furnace before. It seems like the walls erode to a degree and then it stops. For me that happens at a thickeness of about 1 inch. Of course when the wall gets so thin there is going to be more heat loss but I don't suspect that if we kept the furnace going it would have caused the furnace to collapse. The wall becomes glass-like and fuses together making it more "solid" structurally.

I have tried ash and fireclay in the mix of the refractory for the walls before. They all seemed to perform similarly. Although I have never used kaolin.

The great thing about this forum is the sharing of ideas and experiences. We could keep going by ourselves with this trial and error process and continue to post the results and so forth. It would be great to have an opportunity to get as many of us interested in this stuff together in one place and share what we know in order to move ahead further. It would be even better as Mike pointed out if we could convince someone like Mr. Kihara to return to the States for a show and tell. I suspect that will require some sponsorship or the influence of a university.

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And here I was ready to make me some four inch thick bricks...

 

Our experience this last may was with a combination of bricks and ball clay, and some mizzou castable refractory. The clay and castable got chewed up pretty quick, but the bricks underneath held out allright. I was thinking, when I make my bricks, of doing some special purpose ones to get a more slanted angle at the base of the pit, much like Mike and Randall's in 2006 at Harley's... hoping that it would melt away partially, giving room for the bloom to grow.

 

I don't mind making a one-time-use furnace, it will be small anyway, and I'd have a tough time leaving it up long term. And, I only have so much ore to start with. But I did see some videos on YouTube that showed permanant furnaces, and guys having a heck of a time digging the bloom out of them without hurting the structure. While wasteful, the tear-down design sure seems a lot easier to me.

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...

Of course this is all predicated on building a furnace you can reuse, that is, getting the bloom out without taking the furnace apart.

 

I suspect the main reason for the destruction of the tatara furnace is that it's the easiest way to deal with a bloom of several hundred or even several thousand pounds.

...

Anyway, I guess I'm trying to say the whole furnace design thing is about balancing insulation (to save fuel) and conduction (to save the furnace wall), all variable according to materials.

 

I'd agree with all of the above. While it would be really nice to have a reusable furnace that never eroded, I don't think that should be more than a goal. If erosion occurs, or is planned for, the bloom will always exceed the external diameter of any port available for extraction.

 

The other item is balancing heat produced against heat lost. In that equation, the two end points that Lee & Company and myself/Jesus and others are different. These stacks, that I learned to build and Jesus/Walter have varied, are not intended to produce iron, but steel, and ultra high carbon steel at that. IMO, given my limited experience, which includes observation of the murage at work, thin walls and high radiation negatively affect the atmosphere desired for steel production. This may not be the case for iron production. Basically this process of producing enough heat and controlling the heat lost are critical for either end point but differ in the application.

Edited by Mike Blue
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Jesus, Walter-

 

When I wrote the earlier reply I hadn't noticed the two following pages of stuff (duh).

 

I wonder if the elevated carbon problem(if that's what it is) is connected to your refractory recipe. The portland is mostly calcium, the vermiculite has magnesia and alumina, all those are bad things for the slag, reduce the slag's potential for decarburization.

 

I disagree with Mike's idea that making iron and steel are really different. I think the stack reduction in any bloomery produces a high carbon product, and then is decarburized in the hearth. How much it's decarburized depends on how much slag you keep in there, and what the chemistry of that slag is. Iron in the slag decarburizes the bloom, other stuff in it doesn't.

 

That's why, to make lower carbon stuff, we try to keep wall erosion out of the equation. I think one reason the tatara makes steelier stuff is because it continually adds the eroding sand/clay mix to the slag (the bottom sacrificial section is mostly sand.) Seems like if you want to approximate that process, with wall erosion contributing to the slag, you ought to try to make sure the slag you're making is chemically similar, or you could chase down a lot of dead end roads.

 

I avoided clay for a long time too, but I think if you try it a couple of times you'll find it's actually a lot less hassle than what you're building. Plus cheap and infinitely recyclable.

 

One last related idea- if the other chunks seem to be too high carbon too, and you've got to cobble up a little charcoal forge anyway, you could try tossing fresh ore on it as you reheat it.

 

Sorry for more gratuitous advice, but your smelt is what I entertained my brain with while I sat on the deer stand this evening.

 

Rock on-

 

Lee

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