The following instructions are for Modified Commercial hives but will fit National equally well. Other hives will need to adapt the dimensions to the size of their brood boxes.
Using some board (MDF, ply, fibre-board etc) about 16mm thick (this is not critical but it should not be too thin) which will not be affected by getting a little damp, cut out a section 1.02m * 0.46m. Save spare bits as some will be needed later.
Use batten to edge the timber – see photo 1. I used some 18mm * 34mm * 2.1m batten as this was laying around spare but any spare timber of similar size and thickness will do, it just has to allow for a bee space. Screw this into place leaving about a 5-6 cm gap for the entrance to the brood side, marked with a B in the photo below.
Now to put the divider and its cover between the area for the brood box and the stack of supers. Measure and mark a point 18 1/4″ from the left hand side of the top batten and mark this point. Repeat this for the bottom batten. Do the same for the right hand side (where the arrow is). This will make the area you have to cover between the brood and supers very obvious. In the picture above this space has blocks marked with masking tape filling it, leaving a 10cm gap between them for the bees to get to the supers.
Until now all this woodwork has been on one level. Now, you need to have a section of board that covers this strip between the two blocks you have just fitted. This needs to achieve a bee tight fit between the brood and supers being stacked on it. The finished board should look like that below.
This board is purely for drying extracted supers. While the standard recommendation is to place wet supers back on the hive they came from (to prevent disease spread), if you have several hives it is simpler to work on an apiary basis rather than hive. You will also need to have a stand capable of supporting a double-width floor-board.
1. Check the supporting stand can hold the double floor-board.
2. Exchange the current floor-board for the double one around mid-day and block the passage way to the super area with a wet sponge
3. During the evening (after flying has ceased), remove the wet sponge, add an empty super with a queen excluder on the top of it to the (arrowed) super side of the floor-board.
4. Add the wet supers over the queen excluder and cover with a secure (bee tight) crown board and a roof.
5. Add some weight to the top of both roofs if in a windy position to ensure they do not get blown off.
The limit on number of supers is your height and the amount of supers you think will stay on the floor, I tended to leave it at 6-8 and add weights to the roof over the supers.
How long do you leave these? Well this depends on temperature, if it is comfortable wearing shorts and T shirts, then 2-3 days should be more than enough as the bees will rob most of the residue overnight. Check before removing.
When the supers are removed you will find a lot of residue, wax etc on the floor of the Super area of the double floor board, please remove this asap even if you intend to use the floor for a second or third set of supers as wax moth can invade this wax and cause problems later.
That’s all there is to it,