Gary Fisher wrote:Thank you Max for your answers. I appreciate it. Thanks for the link as well.
Just to clarify your answer on barrel gap, for an 8 in riser, you meant the 8 inch gap is the gap between the riser and the edge of the barrel, right?
The other "gap", is the space from the top of the riser to the top of the second barrel. I understood that the riser should go up to about three inches below the top of the first barrel, and then place another barrel on top of that. Did I get that wrong?
Sure enjoying looking at the link you sent. Thanks again
Glenn Herbert wrote:US standard firebricks are 4 1/2" x 9" x 2 1/2" or sometimes 3", so they should almost precisely make up the 17 7/8" height from the chart. I have seen off-brand firebricks with smaller dimensions, maybe 4 1/4" x 8 1/2". Be aware of the possibility if buying firebricks from different sources.
Peter van den Berg wrote:
Robert Dearborn wrote:One feature im unclear on from the sketches and the podcast - is there a heat riser inside the barrel above the heater ? What is its proportion ? Im assuming it doesnt reach to within 2" of the underside of THAT monster barrel !
Your assumption is spot on, there is a riser inside the barrels. It's reaching up to about 3 to 4 inches below the top of the first one, so the top gap is one barrel plus 3". The riser is an 8" ceramic fiber tube, it could be shorter but it is being used as a whole.
The space around the riser and the firebricks is filled in with a perlite/clay slip in order to fix it in place.
The barrels happened to be open-top types. Ernie adviced to fit the lid around the riser and cut open the bottom end of both the stacked drums. It is even possible to extend the tower with yet another barrel. The gap between the riser and the hole in the lid is stuffed with superwool, of course.
When cutting, one inch of the bottom has been left around the perimeter, this way there's a better chance the barrel would stay circular.
Gary Fisher wrote:
This question is for Max or Peter. I asked Max earlier about this top gap, and here it appears that the gap is three inches plus a whole barrel above the riser. I seemed to understand from Max, that the top gap is 8 inches from the top of an 8 in riser. What did I miss in my interpretation?
Gary Fisher wrote:This question is for Max or Peter. I asked Max earlier about this top gap, and here it appears that the gap is three inches plus a whole barrel above the riser. I seemed to understand from Max, that the top gap is 8 inches from the top of an 8 in riser. What did I miss in my interpretation?