Every once in awhile I was seeing some severe heat damage to the lower button, particularly when using the nylon buttons with HPR motors. I began watching the launches closely and discovered something quite fascinating. The flame from the motor was hitting the blast deflector and spreading out. A portion of the flame would hit the rail and actually ride back up the channel! The problem is that most blast deflectors are flat, which isn't a design issue when using rods and is the easiest to engineer. I started raising my standoff distance and that took care of the problem, although it reduced my guidance length.

Not too long ago this topic came up on RMR and I found out I wasn't alone. In fact, some folks were also seeing heat damage to the airframe itself right along the rail slot. Dean Roth submitted a very simple and inexpensive solution to the problem. He was kind enough to pass along these photos which should be pretty self explanatory.