Douglas Cooke wrote: >I thought that's the foam we're supposed to be using....the (formerly) blue >(now green) extruded polystyrene insulation sheets that come in 1" or 2" >thick sheets from Lowes. > Am I wrong?
Without searching through the plans and citing exact statements, I can say that urethane foam is certainly the expectation, and the parts list that came with my plans calls out urethane foam panels of various thicknesses. Page 10 of the KR2 plans certainly calls out urethane foam in the only sentence under the heading of "SHAPING FOAM". That's not to say that you can't use other foams, as long as you consider the foam-eating effects of chemicals, gasolines, and even some epoxies. But as was mentioned, there's nothing wrong with using polystyrene other than it's a seriously larger effort to sand it, and it'll weigh a little more. Of course the canard guys have demonstrated that polystyrene is easy to hot-wire, and works well for aircraft use. Another upside is that I'll bet it's a lot less likely to develop skin bubbles, due to an improved tensile strength of the surface, making the glue bond stronger. The tensile strength of urethane foam far lower. You'll be OK, and I'll bet your biceps are getting bigger by the day... Mark Langford ML at N56ML.com website at http://www.N56ML.com --------------------------------------------------------
