by Nirky » Thu Oct 23, 2014 9:39 pm
I took all your advice and put a 4" pad of perlite/fire clay/fireplace mortar on the cement floor, then rebuilt the core & riser on top.
Surrounded the core with 2+ inches of perlite.
Before, after several 3 & 4 hr burns, only the top third of the prism developed that blue discoloration.
Now after one 4-hr burn, most all of the prism is blueish, so it seems the temps are considerably higher.
Poured a 4-inch thick wall of concrete around the perimeter of the bricks, so no smoke leaks anymore.
One strange thing, it has a strong draw and the rocket is loud, but at times it will pulsate. Like 4 or 5 pulses per second.
Is that some kind of restriction in the system somewhere? It pulsated at times on the first build also.
Still don't have an insulating blanket around the riser yet, that's the next step.
I don't think I'll ever get over Macho Grande, those wounds run pretty deep.