How thick of a refractory cement lining in a coal forge?

[Craig Stebbins]

I recently picked up complete Buffalo #3 boilermaker forge  and have found some info stating that it should be lined with refractory clay or refractory cement.

Where can one get these refractory materials, locally in the PNW?

How thick of a layer is needed?

Should the cement be formed around the tuyere to create a fire pot?

Here's some pictures:

 

[NathanM]

May be a long shot, but did you ever come up with an answer?

[Charles R. Stevens]

this may have slipped threw the cracks because we see this or a variation of this question so often. 
All clays are refractory, some are more resistant to heat than others. 
almost any clay you dig up, find in a road cut, River bank or other formation where you can see the stratification of the soil will work. 
you can also go to a building supply and buy a bag of fire clay and a bag of builders sand. Mix 2 parts powdered clay to one part sand (there are other grogs that will work well such as ground fire brick, grog from a pottery supply, volcanic ash and diatomic earth to name a few) the sand cuts down on cracks. Wet it, and trow it in a bucket or tub. You want it stuff but evenly moist. It shouldn’t stick to your hands. 
now fill the forge with clay to with in 2” of the top. This is the hearth. Dig out a bowl about the size of your two fists (cereal bowl) over the tuyere and form a 1” rim around it. 
mince dry (or close) fill the forge with coal to level. The 2” shallow space holds extra fuel. Now pull the extra fuel in to form a mound over the bowl as you need as much fuel over the material as you do under it. 
understand that is is for coal, charcoal is a different animal and takes a different hearth shape as the extra fuel will all light. 
a watering can is recommended to dampen the coal to keep the fire from growing to large and help stick the coke together. 
hope that helped. 
refractory cements are expensive and slag sticks like glue to it. 
man alternative is to fill the forge with fly ash (coal ash) and clinker  and reform the bowl as needed. You will still want to keep the ash about 2” below the rim (you will have to remove some ash from time to time to as you form more in the forge. 
clinker will stick to citified clay as well cut a little wood ash creeps that to a minimum. 

[NathanM]

3 hours ago, Charles R. Stevens said:

All clays are refractory, some are more resistant to heat than others. 
almost any clay you dig up, find in a road cut, River bank or other formation where you can see the stratification of the soil will work. Mix 2 parts powdered clay to one part sand (there are other grogs that will work well such as ground fire brick, grog from a pottery supply, volcanic ash and diatomic earth to name a few) the sand cuts down on cracks. 

thank you for the reply. do you have any examples? like pictures? I will try this and post a picture when I can. I'm new to coal forges. I could not pass up bring this old girl back to life. its a antique buffalo forge.  the last photo is my best guess as to what it used to look like.

I have been using propane for a few years now. its time to expand my knowledge a little bit and have a bit more freedom on stock sizes.

 

[Frosty]

Neat old forge. I'd brush the loose rust dust out of the pan an ram it with clayey sand, my preference is 1-2 pts sand to 1 pt clay but that's just MY preference, not the "right" mix. I'd fill it till the clay just covered the hump for the blower and dish it down over the air grate like Charles says but bring the clay level with the air grate flange. 

Rebuilding the mechanics will be fun project times.

Frosty The Lucky.

[NathanM]

Charles R. Stevens,

Thank you. Your comment is very descriptive. i wish i had read the forms a little more before posting. but, im glad i found the this forum any how!

Frosty, 

Thank you as well. I will post some updated pictures when I can. I found the blower blades to be in pretty poor shape. I'm going to replace them. Then try to clay line the forge. Any idea where I can find another blower grate? This one is in very poor shape.

[Goods]

They are still sold from the larger blacksmith supply companies. I purchased one myself (from centaur forge?) for a small rivet forge. Many blacksmiths just fabricate their own. Just a 3/8~1/2” round bar grate and clay them in place.

Keep it fun,

David