Hi I'm attempting my first rocket mass heater based off the 3rd edition of ianto Evans book. We we're unable to do the brickwork in a 7 inch by 7 inch square or 6 by 8 rectangle without breaking lots of fire brick. We got close (6 and 1/2 by 9 in) and decided to roll with it and it works. The other questionable thing was the mortar, maybe I used too much sand, it was hard to apply and didn't seem to seal the gaps very well between the bricks although I stuffed as much in as I could. For the insulation container we cuth lath and attached with bailing wire, but this expanded buy an inch and a half once filled with perlite and vermiculite thus leaving approximately .75 in space between barrel and insulation. also its a bit wonky and has to touch the barrel in some places. however when fired the smoke still came down like it should, smoking out the bottom of the barrel. should i rebuild, partial rebuild or go forth? thanks
