Concrete challenge 3, the bookend
Day two of concrete week, and this time something for indoors.
Yesterday’s concrete was for the garden. Today’s is for a shelf, because I would rather make things that have a job than things that only have a look, and what I actually needed was a bookend.
The letter B does three jobs at once here: books, böcker, and my own initial.
The mould
A plastic Ferrero Rocher tub. A shape that is otherwise entirely useless and happens to be exactly a bookend: two flat faces meeting at a right angle.
The MDF letter came out of a craft swap about a year ago and had been waiting for a purpose.
Oil the inside of a rigid mould. Vegetable oil, brushed on, everywhere the concrete will touch. I still ended up breaking the tub to get the bookend out, and I am fairly sure it would have been worse without it.
Casting
The letter goes face down in the bottom of the lid, and the mix goes into both sides of the container around it.
Then 24 hours in the garage. Not outside in the sun, it dries too fast out there and cures weak.
After that, break the mould off and dig the piece out. Some concrete had crept under the edges of the letter, so it needed a bit of scraping to bring the B properly out of the face. Then spray with water several times over the following day to keep the cure going.
The letter got painted white afterwards, and the underside got felt pads so it does not drag across the shelf.
About the bubbles
If you are wondering about the air bubbles: I like them, and I am not going to pretend otherwise.
But there is a real pattern in them, and it took a weekend of making several of these to notice. The pieces cast in closed containers came out with far more bubbles than the ones cast in open moulds. The reason is obvious once you see it. With an open mould you can tap and shake the air up and out, and with a sealed tub you cannot.
So if you want a clean face, cast open. If you do not mind the texture, either.
Have you tried concrete? It is genuinely messy and genuinely good fun.