Lining for coal forge

[Caballo bueno]

Hello! I continue with my research on lateral blast forges and my question is if there is any clay or sand that repels the slag and does not stick to it.

Greetings

[Charles R. Stevens]

Neither. Slag sticks to vitrified clay like glue, and sand melts and forms slag.the combination of about 1/3 clay and about 2/3 sand ( it’s actually dependent of on the type of clay and the amount of silt) is much better. Wood or coal ash added to the mix is the real magic ingredient.
now that said, charcoal produces very little slag if it’s clean and you font burn up a lot of steel (old nails from palette wood is an issue) . And coal usually has a hearth an inch or two lower with coal piled up, the accumulated ash on top of the clay prevents the slag from sticking. The real problem comes in using a forge optimized for charcoal with coal. 

[Frosty]

We've answered this to our best ability already, the answer hasn't changed. Slag is largely silicates and sticks to darned near everything including the inside of cast iron fire pots. 

One of the reasons to use a compacted earth forge is they let you rake out the contaminated clay and throw it back in the ditch you got it from. 

You are looking for sure answers in a craft that has very few.

Frosty The Lucky.

[Caballo bueno]

I understand... I mean, do I use ashes and the charcoal powder from the mixture? Does the clay that I mix with the sand have to be refractory? What about the cat litter?

[Frosty]

No, it doesn't need to be special at all, any mineral soil that will pack reasonably hard with just a LITTLE moisture works just fine. If you mix wood ash, NOT charcoal, ash with soil it clinker will stick less. 

If you know of a puddle or ditch that forms cracks when it dries, that soil will work just fine, especially if you mix wood ash with it. And no, I can't tell you how much ash to mix in. If you add so much the soil won't compact, add a little more soil. This is a by feel thing, just like blacksmithing.

Frosty The Lucky.

[TWISTEDWILLOW]

I think the last forge I lined I used two coffee cans of wood ash out of the stove three crushed an pulverized fire bricks, and 20-25 pounds of red dirt clay outta the driveway,

[Caballo bueno]

Okay. What if I mix it with lime? How do I protect the tube from burning without using a water tank behind it?

[Frosty]

Make 50 - 100mm of the end near the fire easy to replace.

Frosty The Lucky.

[Charles R. Stevens]

Lime and clay make cement, heat breaks it back down. Use ash. 
lit you wrap a sheet of paper  around the tuyere and then make it flush with the dirt it’s easy to replace but protected. 

[Caballo bueno]

With which biker could I wrap the nozzle so that it doesn't burn?

[Frosty]

I'm going to wait for your reply Charles, I just gotta hear this one. My brain lives in the puniverse and I don't see a connection but what the hey I don't know what what you said means in Spanish either.

Frosty The Lucky.

[TWISTEDWILLOW]

Steady on there Jerry!

[Frosty]

I marked this thread to follow Billy. I don't want to miss anything.

Frosty The Lucky.

[TWISTEDWILLOW]

lol 

[Charles R. Stevens]

Adaptive text is not my friend. I can look like an idiot with out Apple’s help. But I must say, if you have already succeeded in wrapping a biker around your tuyere, I don’t want to be an your “not my friend” list! 
But seriously, it doesn’t matter. The idea behind the paper is that you can remove and replace or simply push the tuyere in if the tip burns up. In truth, the clay will vitrify and form its own tunnel even if the tuyere burns up. If you are worried it will spin just leave off the paper.

[Caballo bueno]

Is silica sand essential? What mix would you use your Charles?

 

[Charles R. Stevens]

No it isn’t, pure clay or clay/silt is fine. Simply put, think adobe brick. 

[Caballo bueno]

but the clay can get very hard and the slag when sticking will not take a good piece?

[Frosty]

Mi amigo, you are asking questions we can't possibly answer. A dirt forge where you are is as different from a dirt forge where I live or Charles lives as fish in different oceans. As you've been told several times YOU have to try it yourself and see how your soil reacts to slag  IF you produce slag at all. A charcoal fire rarely produces enough slag to be a problem. 

Nobody's angry but you are asking the same question over and over and ignoring our answers. If you keep doing that people will stop responding to you at all. Well, maybe if you ask something new but I know I'm done talking about dirt forges with you. Does that make sense? 

What you need to do is make a forge, build a fire and start forging. We WILL be happy to help you learn the craft but you have to be willing to listen and try suggestions or we are wasting our time. 

So please build a forge, fire and start hitting steel with a hammer.

Frosty The Lucky.

[Charles R. Stevens]

I realize that their is a language barrier, and Google translate is iffy and literal. I will try to explain.

pure clay will work, just damp and rammed in place, it will vitrify. Clay can be cut with sand buy about 1/3 and still vitrify like pottery. 

simpler is to use an adobe soil or mix. Adobe can be from 10-33%clay, 50-66% sand and the remainder silt. Simply put non organic soil in a jar, say 1/3-1/2 full and fill with water and shake. Let sit until until it settles. Sand will be on the bottom, silt in the middle and clay on top.  Pretty much anything will work but can be adjusted closer to ideal. 
With adobe one can make brick or cob, one may mix chopped straw or cow/horse manure , sometimes the liquid from cooked cactus or cooked wheat flour paste (gravy) to make up for low to poor clay and high silt levels. 
A good dose 10% or so of wood or coal ash will help stabilize and shed slag.

Adobe will still partly vitrify but will not be as water/erosion resistant and high clay, low silt mixes. 

this “ideal” but not needed, any mineral soil will work, tho more or less maintenance may be needed and the ash formed in working generally acts as a flux to keep slag from sticking to bad.

 

 

[Caballo bueno]

if I say it because of the slag that sticks and you take half a forge if the mortar is not good...

[Frosty]

You are imagining problems that are NOT that bad, clinker sticking to the dirt will NOT take half away when you rake it out. Just compact damp dirt in your forge and keep the clinker cleaned out as you work. If the compacted soil gets thin compact more in. 

This is really easy, it's not as hard as making sand castles on the beach. 

Frosty The Lucky.

[Fly]

Sounds like the tower of babble on ? 
 

            Fly
  

[Frosty]

Babble on? Is that a shot? Do we know each other or something? You're off to a good start already. 

Frosty The Lucky.

[ThomasPowers]

Yes Frosty; but you yourself are a tower of punditry.