Maybe I am all fingers and thumbs but one area I have had a problem with in the past was inserting a small piece of foundation into Apidea frames. I melted wax and poured some along the top bar, and the piece of wax looked fine and secure. That is until the bees clustered on it. Then several of them fell down. The bees were then free to build as they wished, and they did not always respect the frames. Then, I discovered a far quicker and easier way of doing the job. Simply use a squeeze of PVA glue along the top bar between the two ridges. Insert the wax and leave it to dry. No melting and possible spilling of wax. The glue dries to an almost invisible line, and the bees have no objection to it. Later, when it comes to salvaging the comb, the thread of PVA will just pull off from the wax or the frame. It is far quicker and involves much less mess than using melted wax.