Both
Jalousie windows on my
Boler leaked. And boy was it subtle. You couldnt see it, but my bed cushions were getting damp. Then one day I noticed, more out of the corner of my eye, one droplet of water running down from one corner of the window frame inside. I jacked the trailer out of level to the back, and watched as several droplets formed and ran down.
The plywood inserts into which the window unit was fastened were acting like a sponge....they were soaking wet, and half rotten. Out the
windows came, in went new plywood inserts (made of treated PWF this time) and back the windows went with new Butyl. No more damp cushions.
The belly band is not an issue, or at least on my egg. The shell halves were glassed together quite well, and the band itself seems to play only a minor role in keeping the top half fastened on.