There is a bit of an art to it
This is how I use a knife
Dont leave it on or the honey will burn, switch it on to get it hot and use the on off switch to regulate the heat. The latest ones seem to have better heat regulation then the early ones
Get a piece of wood and put a nail through the middle so that the point sticks upwards. Get a large tray and fasten the wood with the nail sticking upwards across the corner. Take a frame and balance one end of the top bar on the nail with the top bar towards you and presuming you are right handed tilt the frame forwards. With the hot knife start at the bottom and with a slight sawing action, using the top bar as a guide, move the knife upwards, the cappings will come off in a big sheet and because you have tilted the frame they will hang clear of it u til you reach the top at which point the whole lot drops into your tray. Change the frame so the other end of the top bar is on the nail and repeat for the other side. Turn the knife off while preparing the next frame or the honey left on it will burn.
If you are using a heat gun, a paint stripper gun will work although I use one intended for making models, or buy a pucker one, then use the same set up with the nail. This time you need to swing the nozel of the gun from side to side starting at the top. Dont leave it pointing in one direction or you will melt a hole the whole way through. The cappings will start to pop open unless they are soaked in honey in which case a hot gun will not work. The reason for starting at the top is that you follow the melting cappings down the frame rather than them sealing up the cells you have just opened. There will be no sticky honey or cappings. They just pop open. The cells will look a bit thick on the outside when you have finished but the bees sort them out when they get them the following year. You need paper down as the popping wax can go on your floor!
I always use a hot air gun now. It is so much easier than a knife but the knife does work and does give you nice wax cappings for using.
Hope this is helpful, others will have other methods but this is the way I do it!!
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