BHMC , Just my thoughts ? Pros -no cost .Cons -Unless the field stone is heavly insulated and fire bricked (and even than?)May get hot ! crack and blow apart !.Concret blocks ( heavly insulated and fire bricked ) even crack sometimes ,but work well and are easy to frame with angle iron /front door /rear stack .
However ,Iv'e seen a many a thing work, if a little thought is put into it ...So if all u gots is field stone ? Wear football gear an helmet ? lol .
But it dose sound like u got a nice start with the pans ! Good luck tappin !
2009 50 taps,outside barrow stove, 2 1/2 gals
2010 75 taps 12x12 w/upstairs Scrap made sugar shack,barrow stove 4 1/2 gals
2011 200+ taps,tubeing gravty feed shack,scrap oil/wood furnace homemade into a 2x6 arch upstairs holding tank and a new pump(thanks to my son Brian)Sap&wood hauler-4 g-kids model A front end,fram, spoked rims, and a tractor trailer rearend (just don't get in her way), lol, speaking of that,she now thinks "I've gone over the edge",that is (otherhaft) Total 35 gals.