Formwork, the woodwork you throw away

interesting…hope I get to sit in it someday.

-- Dan, Sterling Alaska, Before you criticise some one, walk a mile in their shoes...then you will be a mile away and you have their shoes!

In my youth I worked with a guy building forms for boat hulls. First you built a very heavy duty hull out of wood – the plug as I recall. Then that was sanded and waxed to death – mine. Next the plug was sprayed with gel-coat and layered with fiberglass and steel bracing to make the final mold. The plugs could actually be sold to build a all wood boat. My father and I built a work boat out of one. Not quite the scale of an amphitheater though.

-- -- Chuck S.

this took an eight man crew working a ton of OT roughly two months. they were awesome.

-- measure once, keep cuttin' til it fits

What happens to all that lumber? I don’t imagine that is high grade stuff and has a lot of nails and other issues… but still…

-- -- Chuck S.

the 16’ 2×4 waler pieces get saved, the rest goes into the wood recycle dumpster. the 1/2” mdo is $50-60 a sheet, but once you bend it and pour against it, it kinda laminates it into that shape permanently. so unless you’ve got another 85 foot radius wall/bench to do it’s done.

-- measure once, keep cuttin' til it fits

Cool looking project. I dare say most of us don’t work on that sort of scale.

-- Bob www.singularengineering.com - A sideline, not how I earn a living

My wonderful father-in-law and his brother worked, shaped and installed thousands of wood forms for concrete pours; from extreme below ground freeze to 50-story buildings.
One sage of advice was never re-reuse cement-smeared forms.

Naturally, being inquisitive as well as stubborn, had to experiment.
Within 20-seconds each on a grinder, then a ROS, the cloud of dust was impressive …and dangerous.
The dust cloud traveled some 75-100 feet.