Atomic77 wrote:Sounds like you are going the aluminum route, so this opinion probably doesn't matter, but...
I used Filon on my build. I got it from an RV surplus shop in a roll. I didn't know if I should float it or glue it. The opinions around here were pretty much 50/50 so I flipped a coin and floating won. For mine, it didn't work. As soon as it warmed up out in the sun it warped like mad. My guess is the amount of linear feet had something to do with it and it compounded with every inch. So, round two... I bought red glue, a contact adhesive made specifically for Filon and sprayed both surfaces with a throw away Harbor Freight gun. Should have done it the first time because it is flat and beautiful. I've had it in the sun with 125 degrees on a point and shoot thermometer and it's great. Check out my build if you're interested in the Filon debacle.
I looked into filon and my only sources cost more the aluminum sheets considering I was able to find 4x8 and 4x10 for 30ish and 40ish dollars with free delivery from the neighboring city. Thanks for sharing your experiences. You address some interesting questions. Because at some point products do have to be supported and since Filon is much thinner than FRP and NRP panels I would think you would definitely need some support in the middle of long runs. I am thinking that glues have made some improvements over the past few years and stuff is just plain better in terms of flexibility, elasticity, and fun stuff like that. Even the tapes that are available now are pretty interesting. I used some 3M flashing tape as a backup backer to my riveted seams (still put butyl between the sheets) and that stuff is cool. Supper rubbery, super sticky, and puncture resistant like you wouldn't believe.
Did you just use a flush cut router bit to trim the edges to shape or did you mark and cut separately? I would think that filon would route nicely if the blade was sharp and speed was kept consistent. Either that or it melts and binds up and does weird stuff.
I will be sure to poke around your build!