Dale Farmer wrote:

Then again, we have concrete chairs. And a B12 (12 ga 2x3 U-shape) Unistrut
armchair with webs of closely-spaced struts touching a body and flanges
facing away might be a good heat sink. We might use 150' of strut (about
400 pounds) with lots of 1/2" bolts and right-angle connectors.

...Do you have pictures on the web someplace of these chairs?

Not yet. Picture a 4' vertical piece for a back slice plus a 2' horizontal
piece for a seat slice plus a 2' leg, bolted into an h, with 16 h slices
bolted side-by-side to make the chair, altho the extra legs wouldn't do much
for heat sinking (we might save 2x14x2x2.484 = 139 pounds with 4 vs 32 legs,
at the cost of some stability and theft-prevention and ambience.) Each arm
might be 4 2' pieces, with a 2' piece behind the back and longer front legs
A 600 pound 4'x8' Unistrut table would also be nice, with 12.5 ga high-tensile
wire and rotary fence wire tighteners for bracing. Tractor Supply sells this
200K psi "active" wire in $77 4000' rolls, with $20 spinning jennys to unwind
it and $1 springs to measure the tension. It breaks at about 1650 pounds. The
tighteners cost about $2 each. Unistrut twitch sticks would be an alternative.

Nick