Interesting thought. Not jumping in on either side of this discussion but those that know me know that I usually run off to find the nearest expert to get the facts when a discussion like this comes up. In this case I headed for my library. I don't think much of Martin Hollman but in this case he is just reporting facts from reputable sources. In his book "Modern Aircraft Design Volume 2" he lists some temperatures that were measured by embedded thermocouples in the Red Lancair 320 factory demonstrator.
A surface temperature of 153F was measured on the top surface of the wing on a 95F ambient day at Oshkosh. A surface temperature of 180F was measured on a 104F ambient day. On the same type of surface but painted white a surface temperature of 126F was measured on a 95F ambient day. The glass transition temperature for Safe-T-Poxy With room temperature cure is 151F but when post cured at a temperature of 200F the glass transition temperature goes up to 196F. I wonder if sitting out on a hot asphalt ramp would result in a post cure that would actually increase the glass transition temperature. Just don't think I would want to launch into the wild blue immediately after the first environmental post cure before the surfaces had a chance to return to normal temperatures. :-) Just the facts mam. Now on Dana's black RV-7 I think the only thing he should be concerned with it the glass transition temperature of his posterior :-) Steve Eberhart Ameet Savant wrote: > Okay, > > I am not totally convinced with this argument. > > If the heat radiating from a really hot asphalt > parking spot happens to delaminate your airfoil skin > over and over again. The birds flights also impose > repeated stresses on the delaminated skins. then > eventually the skin might depart from the structure. I > don't think an aircraft can fly only on it's "wood > spars". > > You give the anology of the steel structure with > fabric on it. well I don;t think the plane can fly > with the fabric torn in many places. I am talking > about the wing only... The fueslage might be ok. > However, I wouldn't want to reskin my fuselage every > few years. > > The pain looks great!... but I have concerns that it > is an unneccesary risk for an otherwise beautiful job! > > my 2ยข > > Ameet Savant > > >>I'm surprised that nobody's pointed out that >>the manual says to >>paint the thing white yet. My argument is that the >>structure of this plane >>is wood, not composite. All the composite stuff >>does while on the ground is >>help the airfoils and decks retain their shape >>(kinda like fabric on a steel >>tube plane). The spar and landing gear take the 1g >>loads while sitting on >>the ground. When flying, the skin temperature will >>be down to ambient about >>100 yards down the runway on takeoff, if not while >>taxiing, so it's not a >>factor. > > >>Mark Langford, Huntsville, AL > > > > __________________________________ > Do you Yahoo!? > The New Yahoo! Shopping - with improved product search > http://shopping.yahoo.com > > _______________________________________________ > see KRnet list details at http://www.krnet.org/instructions.html >
