Last pour! We might be getting there.
This time I used a plaster based setting drywall compound.
The sink mold, just before installation:
The plaster, combined with the use of hot melt glue, cut production time significantly, despite the extra details. It was a lot of fun.
That is, until stripping time...
See those hardwood wedges under the hammer? Custom made chisels. The plaster stuck just as hard to the concrete as it did to itself. Metal chisels can scratch the cement. Wooden chisels were OK.
You're thinking of water, aren't you? Yes, I tried it. Two messes instead of one.
Note: the plaster got painted with polyurethane as a sealer a few days before the cement was poured. Umm... remind me... what is the main ingredient in all those sticky things like spray-in foam, gorilla glue and PL-400? It wasn't... by any chance...
polyurethane?
Nevertheless, it only added a day or so to the process, so I'm still way
ahead of schedule. Next time, though, we find a better release agent!
On to filling all those holes and polishing!