I have found beekeeping dummy boards to be quite expensive, especially if you use 14×12 boxes like me (approx £7). As a result I have often done without, which has on occasion given me grief of brace comb to the wall, or in other cases a whole new piece of comb handing from the roof.
This year I’ve decided I’ve had enough and that I would make some.
I had spare top bars, so I used those – but you could easily use top bars from old frames, just clean and scorch them (or soak in 1:10 bleach or boil in washing soda) to make sure they are disease free.
Drill 3 small holes in each, smaller than the screws you are about to be using
Add a line of glue
Cut some sheets of plywood to fit – I lined it up with a brood frame to check the height and the box for the width. Don’t forget the top bar adds a little height (like I did before cutting)
I used 12mm which is a bit overkill, but was what I had to hand – 9mm is probably best, with rigidity and ability to drill into from above. 3mm will glue on / nail on, but in previous experiments has been very flimsy / prone to damage and warping in practice. more than 12mm will protrude and may not sit flat with the weight. I used marine ply, which will probably last better in the humidity of a beehive .
I cut it with a mini circular saw, which left me with a bit of a messy edge, a rasp soon sorted this out.
Attach the top bar to the ply wood, using the glue and holding it tightly in place while screwing in. When not pre-drilling the holes in the top bar it easily splits (from experience)