A couple of years ago, I spoke with Fred Keller by phone. He is the one that drew the plans for the Defiant. He told me that he used the Dow floatation billets for his wings. However, I have found that if you call Dow and ask questions DO NOT use say anything about planes, or they will hang up on you. They don't want the liability. I haven't been able to build yet due to my daughter still in college so I can't say how this foam performs, however unless there is concrete evidence that it is dangerous to use, I plan on using it. If Bert and Fred used it on the Defiant, then it must be ok.
Steve
