OK then. This tutorial in combination with Lee Sauder's write up from his web site should be all you need.
Here is the new stack I built today. I am using a 12in paper concrete form tube for a form.
These work very well, and you can just burn them as you cure your stack.
It begins by setting it up on whatever you will be using for your plinth/base.
Here we see my new super plinth that is set up on my smelting site in my yard. For demos, 4 solid cinder blocks work just fine.
Yesterday, I made 4 large batched of Sand/peat/crushed stack/clay/water Dragon eggs.
These were made using Lee's formula, plus some of my old stack. The normal formula would be 50lbs sand/equal vol. of peat/mix/add 5 shovels of EPK clay, 1 shovel of ball clay. Mix, add water till sticky, and mailable
Knead it up into balls of 2 fisted size, let them sit in a big bin, or under a tarp overnight. See Lee's page for more info.
Now start building the clay, around whatever form you have made.
I usually break the balls in half, and knead out into a loaf.
I try to keep the wall about 3 in. or so thick here at the base, and thin to 2 in or so near the top.
If you have never worked with clay before(shame on you) go to you tube, and get a clue how to knead it all together.
When you reach your third or forth row. Break out your twine. Tie it around the base, or just stick it in the clay, and start winding it around the stack to hold the clay up. It will want to droop from it's own weight.
Pay attention to be sure you are joining the clay as well as possible.
Do a row at a time. follow with the twine.
I use some bricks to just pinch hold the twine.
And up we go. It was looking like I could make a 40ish in. high stack, with the clay i had prepped. So, that was what i was shooting for.
About 8 in. away from my hight goal now.
It was only 93 deg!
It helps to have some help. (I guess)
Thinning the walls as I get closer to the top. I may have been a bit thin. We will see how it holds up.
I took a break, and outlined the door. I will cut this out once it has cured a bit. The grooves in the plinth is where my removable bricks are. these will come out durring bloom extraction. Allowing the bloom to drop into the lower part of the plinth, which is filled with charcoal fines and ash.
I normally put a piece of pipe where the tuyere will go, but I marked it, and will cut it out durring the cure.
OK then, I made it to my mark with enough clay to do the buttress.
I feel the upper walls may be a bit thin, but the EPK clay is new to me, and I thought I would see how tough it is.
Now with the Buttress around the base.
I will let it air dry till tomorrow eve. then I will get some fire going around and in it to cure the clay.
It is best to fire it right away if you have time.
Get a good fire going outside, until the skin is tough, and pre-cut your door, and tuyere opening.
I have found it is good to have a large bucket of damp clay mixed up to Wash over any cracks that form, and they will.
Not too damp. I just make this mix good for using my hand to wipe it into the outer surface.
Max says," BURN ON", for Sunday!!
After curing in the nice hot sun for a day, I built a good fire around the base. This dried the buttress well, and allowed me to cut the door, and tuyere port.
Once I got the door, and tuyere port cut, I let the fire inside build up to begin fully curing the stack.
The hot sun drying seemed to work quite well. This stack likely cracked less then any I have ever made.
Due to shrinkage, I still felt the walls were a bit thin up top.
After about 3 hrs of good hot fire inside the stack, most everything but the thicker clay on the dragons face had turned a light color. This indicates that it is near dry.
As you can see, I didn't need to fix any cracks.
maybe the only time ever. I guess I had the moisture just about right or something??
In all, the stack shrunk 1.5 in in height, and 1 in in bore.
The walls seem a bit thin to me, but they feel pretty sturdy. We will see, when the real fire starts.
I will do a good preheat on Sunday morning, and then break her in with some easy ore.
This is my tuyere rig.
thick copper about 18 in long.
Copper is best by far.
To get the right angle for your tuyere.
Fold a square paper in half corner to cross lower corner.
you have a 45% angle.
Fold it again. 22.5% That should be close.
Set up the tuyere when your preeheat is near done.
I find it best to be about 2+/- in inside, as close to centered as you can get.
Clay up your door, clay in the tuyere, get the air on, start feeding charcoal.
Have a good bit of wet clay mix standing by for emergencies.
The break in burn went very well. I used my local limonite easy ore. This is the same ore I have already set aside to bring to GW.
Near the end I had a great permanent slag tap going under the bloom.
The new super plinth, based on Lee Sauder's design worked great!
Burning down now.
I have removed the two top bricks from the plinth, in front of the door. I removed the lower half if the door, and started removing the ash, and fines, from below the bloom.
With a bit of nudging, the bloom dropped right out.
Up on the compacting stump. I knocked off all the fluff (very little), and started working it gently at first with a sledge.
It felt very solid, right from the first hits.
Worked it a bit, then got it back into the smelter, for a reheat, and worked it again until it wouldn't move.
Very solid chunk.
The stack came through it very well. There were some superficial outer wall cracks, that I used the wet clay to fix up while it was still hot.
The plinth worked great. I didn't damage the door area at all.
Ready for another burn.
I'm going to the store to buy some beer.
15 lb nugget from 54 lbs of easy ore.
Spark test looks like iron. That was what I was looking for.