I just completed building a Mark Aspery style Side Blast Forge with a Supper Sucker Hood. the chimney is 10: diameter and terminates 4" above the roof peak. The Top Hat is 15" sq. and 11" above the end of the pipe. (The Chimney pipe is from a damaged grain auger ). The Hearth is lined with fire brick, sides and bottom. The interior is filled with wet Wood Ashes tamped down wet. The Hearth is 24" x 23" x 9" deep. The Tuyere is cooked with old antifreeze as the forge is in ab unheated building. The Bosh is a separate tank that connects to the Tuyere thru top and bottom hoses.. This system appears to work perfectly.

Test Fire had the hot spot of the fire against the air tube,Tuyere.  .My Hearth is full to the brim with wood ashes. Can anyone detail where the Duck's Nest should be made in relationship to the . I am burning coal, not charcoal or coke. 

What type of coal are you burning? Size?

For the test burn, a bed of cedar strips was laid and then Tractor Supply Anthracite Nut coal over the kindling. The Anthracite coal was also an experiment. I have Blacksmith coal, stoker coal, and very large chunk coal (baseball to football size).  I bought about 700 # of "basement coal" that consists of 50% fines that pass thru a 1/2" mesh screen and 50% 1/2" to 3/4: size pieces. This will be the coal of choice after the fines are sifted out. The Anthracite coal burned with few clinkers,  The forge easily  heated a 1/2 test rod. 

I didn't like the location of my  hot spot which was directly in front of the Tuyere's air outlet.  I will pile the coal much higher for the next test.

I also moved the area for the fire closer to the hood opening. This was done by sliding the forge forward. My Super Sucker Hood.

Next test fire will reshape the Duck's Nest closer to what is pictured above,  especially the long slope up to the hood entrance..   

I will be taking pictures of the forge next firing when it warms up.

 

Not just to ressurect an old topic, but a sincere thanks for this.  It answered the question that I had before I could ask it.  for anyone who cares, the suggestion to google and add the condition "site:iforgeiron.com" is brilliant.  It's one of those little tricks that has been around but not a lot of people know about it.