by Bobwieser » Tue Mar 31, 2015 10:44 am
Matt, thanks for the complement on my castings. It' all new for me and I'm learning a lot along the way.
That Bucky ball (geodesic dome) came as a result of Thickstrings and you in one of his posts. I had lots of short scraps of 1/2" EMT and wanted a shed, greenhouse, jungle jim for the grandkids.
I fired up the new core with the riser sitting on top. It started nice and went smoke free quickly. After a while I could hear occasional pinging from inside.
I think it was from trapped moisture in the refractory.
There is a specific heating curve for proper firing of the material. I just mixed the feed tube with green twigs and damp sticks that were starting to poke out of the snow.
That stopped the pinging so I continued to burn with a mix of dry and wet wood to keep it hot for 4 or 5 hours. Nothing impressive since I didn't want to ruin it.
I looked inside the next day and see only ashes and a nice white surface in the core.
I did see that pulse mode video of Peters, I'll put a drum on mine to see if it will do the same. I think Peter likened it to an expansion chamber for a 2 cycle engine exhaust system and it needs a drum for it to happen.