Re: Newbie - Rocket Mass Heater Build
Posted: Thu Jun 14, 2012 6:53 pm
Figured i'd better post an update...
Took some pictures but haven't pulled them off the digital camera yet...I made a feed/ burn tunnel like Matt did for his house, using 85% Vermiculite mixed with 15% Clay, 3" around/ under/ over the burn tunnel. It sat inside for two days while i mixed/ cast the heat riser. I used 6"x34" stovepipe inside a 14" diameter grease drum for the heat riser.
After re-reading Matt's thread i figured he let his burn tunnel dry for two days before gently firing it. Last night was at least two days so i fired mine. Within 10 minutes the tripwire and part of the ceiling collapsed. Just looked at the casting a bit ago and it's dry and crumbles easily...maybe they sold me the wrong type of clay? Dunno...
I've got vinyl sign work to do today for customers...$$...But tonight i'll try to build another with ceramic tile above and below the burn tunnel and storebought firebrick comprising the sides of the burn tunnel, re-using the vermiculite all around for insulation. The tile may crack from thermal shock but we'll see.
While it was working last night a friend came over. We noticed just with a temp 6" duct heat riser almost no smoke was making it out, it burned it all up.
Took some pictures but haven't pulled them off the digital camera yet...I made a feed/ burn tunnel like Matt did for his house, using 85% Vermiculite mixed with 15% Clay, 3" around/ under/ over the burn tunnel. It sat inside for two days while i mixed/ cast the heat riser. I used 6"x34" stovepipe inside a 14" diameter grease drum for the heat riser.
After re-reading Matt's thread i figured he let his burn tunnel dry for two days before gently firing it. Last night was at least two days so i fired mine. Within 10 minutes the tripwire and part of the ceiling collapsed. Just looked at the casting a bit ago and it's dry and crumbles easily...maybe they sold me the wrong type of clay? Dunno...
I've got vinyl sign work to do today for customers...$$...But tonight i'll try to build another with ceramic tile above and below the burn tunnel and storebought firebrick comprising the sides of the burn tunnel, re-using the vermiculite all around for insulation. The tile may crack from thermal shock but we'll see.
While it was working last night a friend came over. We noticed just with a temp 6" duct heat riser almost no smoke was making it out, it burned it all up.