Bubblewrap Trough

I liked the round bubblewrap planter so much that I cast a rectangular one also.

I used my regular (favorite) mold, but wrapped each exterior piece with bubblewrap.  The collapsible  inner core of the mold is not shown in this photo.

Detail of the interior corner of the mold.  The blue pieces in the bottom of the mold are 2" rigid foam wrapped in shrink-wrap.

The trough as it came out of the mold.  I didn't do much to it except soften the rim with a wire brush.

Bubblewrap Planter

Three-footed round planter with bubblewrap surface texture that I cast in July.

The mold is a 24" diameter chunk of thick sonotube, lined with bubblewrap, with a piece of 2" rigid foam in the bottom.

No inner core, I just keep the hypertufa mix dry enough to not slump.  I have a belt clamp around the tube because I'd already cut it vertically with a jigsaw to guarantee that I'd wouldn't have to destroy the mold to release the planter.