Side draw chimney
I am using a little 10 gallon steel drum as my side draw forge chimney. I rescued the drum and the grain bin steel siding from a near-by dump.
The forge I have been using in the local museum is side-draft as are most of the smith's in the area. I like the side draft style as it leaves the fire unobstructed and actually pulls the smoke in much better than most overhead hoods.
I went cheap inspired by shady grove and really like how the round forge and round hood look together.