Well...thanks Lili...always a pleasure... Jon.. A DIY Pro.. I'll go visit.. Becky...well thanks..
the foam is your standard building foam like @ homedepot.. and Lowes.. it's the 2" foam here..for insulation.. but I also use the 1 1/2" and 1" for things also.. the 2" has great rigidity and strength and provides lots of surface area for connections..
I've got another couch base for inside planned.. I made a king size thermopedic bed into a queen sized bed for a client.. that was moving... and didn't want to spend another two grand for his favorite bed in a queen size..which was the biggest he could use in the new place... I took the cutoff.. about an 18" x 80" hunk of the highend foam about 14" thick.. I'll work this into something.. outside I'm sure it would hold enough water to always stay wet.. outside that might be a cooling seat for someone without a pool..like a sponge chair..
OH Jon.. my cutting tool of choice... for the rigid foam.. as well as the thermopedic soft mattress foam is the standard old Japanese style pull saw..
picture is of the cool room... before it became the sectional