Step 1: Marking Your Wood.
The bottom is 12-18mm thick and the sides are thinner to save on wood cost. I wouldn't go thinner than 6mm though.
The measurements for the sides are in the pictures. Measure twice before you cut because mistakes cost money.
Step 2: Once Cut, Build It Up.
Make sure you use glue along the edges. Wood glue gives a huge amount of extra strength and you can mix a simple wood filler if you have any gaps. Mix saw dust with wood glue and fill any gaps because you want the bottom to be water proof.
Step 3: Prep for Painting
Step 4: Painting
It is water based but sets like a resin. It's a two part paint so mix small batches at a time because it actually goes a long way. I have built two large grow beds for a large aquaponic system (Pictured above) and a few other bits and I still have about half a tin left.
You will need to seal the wood with the first coat then, once it is dry, sand it down lightly and apply a second coat. Once you are finished painting you can clean up with water.
Step 5: Finishing Touches
Now mix a tiny bit of paint and paint the strips and the hole. I used my excess to paint the front of the box but that's not needed.
Lastly you need to place a small hook under the hole you made. You will hand a small bucket under the hole which will be half full of flour. The maggots then fall from the hole and into the bucket. The flour dries the maggots out which stops them from climbing our of the bucket. When you want to collect your maggots you just put the flour through a sieve that leaves you with just maggots to feed to your fish or other pets.
You can also make a lid for the box to make sure that the maggots all go up the ramp. It also helps because maggots don't like light.
I hope you enjoy building the fly Box and keep an eye out for my next project which is a fly breeding cage that allows you to breed Black Soldier Flies in the UK even in winter. It is a much bigger job but I hope that it will make sense in the long run in savings on fish food and cutting down your carbon footprint while not relying on the sea for fish protein.
Any questions, just ask.