Steve (The Drone) wrote: ↑27 Oct 2018, 20:00
There are plenty of websites out there that will supply Perspex cut to size ( ie 18” squared). Don’t buy any less than 5mm thick as it’s too flexible. Now screw on 7x15 mm strip pine round one side and 10x15mm on t’other. This means that it’s nice and rigid. Now for the hole. You can use a hole cutter and cut it central- ok for big syrup feeders. But!...if you want to feed fondant in winter or during a famine period then cut the hole off centre.
There are a couple of websites with information on how to make Perspex (acrylic) crownboards. Dave Cushman is simple:
http://www.dave-cushman.net/bee/ratquilt.html but as always The Apiarist
http://theapiarist.org/perspex-crownboards/ is rather more comprehensive, covering design, construction, use and cleaning. From my own experience I would agree with not having a hole in the board (see how he uses them to understand)
If you have acess to a router, or even better a router table, there is a simpler, safer, and dare I suggest, a more elegant solution. I order online sheets of Perspex 430 x 430 x 4mm. I then get a couple of metres of planed timber 25 x 50mm (finished size 20x44mm) and run a 4mm wide groove 15mm deep the length of the wood, one beespace (~8mm) from one edge. I then cut the wood into four pieces (exact length depending on what sort of corner joint you want. I am pretentious, cut them to 460mm length and use finger joints) and then slot the four pieces around the Perspex, glue and clamp. I have tried using 5mm and 6mm thick Perspex, but have found 4mm is perfectly adequate.
As long as you have decent lump of PIR insulation (Kingspan, Celotex) above the Perspex there are no significant issues of condensation on the Perspex.