We constructed 2 prototype rocket stoves (using just mud, stones and tin cans) before remodeling the original stove in the kitchen into the third and final rocket stove. On the last one we also used a bit of portland cement, mixed with crushed glass and regular sugar for heat resistance.
The first prototype, heated up fine but produced too much smoke (which shouldn't happen in rocket stoves):
The second prototype, build in three hours, worked perfect, we've been using it ever since:
The final one, 4 pits heater with 2 ovens, took us 4 days:
