I hived a swarm a few weeks ago into my first top bar hive. I had built per Mr. Bush's example and just left a 3/8" space before the first bar to serve an entrance.
All was going well...then the other day I noticed quite a few bee's on the outside near the entrance. As the day wore on the number outside grew larger. That evening I finally went and took a closer look. Upon closer examination I realized that the top bars had swollen because of the humidity and had closed up the opening. The bars had been stored indoors in a nice dry room before being used...I never thought that putting them out in the humidity would result in enough expansion that the entrance would close off. It was tight and had to be pried off. Once I realized what had happened, I removed the spacer that was in place to take up the odd amount of space after the top bars.
All is well now and the girls are back at work. I do enough woodwork that I should have considered the swelling and shrinking of wood due to humidity. Live and learn!
Apart from that little problem, this hive seems to be working great.
Anyone else encounter unforeseen equipment problems like this?