Those tests were likely done with the sun directly overhead. Unless you live in the tropics you won't get the same results.
https://sites.google.com/site/mykr2stretch/ https://sites.google.com/site/mykr2stretch/parts-for-sale On Nov 3, 2013 6:56 AM, "Mark Langford" <ml at n56ml.com> wrote: > Tim Witmer wrote: > > Good info to have in my builders note books. Unfortunately I cannot get my >> printer to copy it. It is too dark. Where did this information originate? >> > > It's page 116 of the KR2 plans. But just because it's printed, doesn't > mean it necessarily applies to this conversation. We don't know anything > about the test conditions or the intent of the chart. I suspect it may > have > come from a standard military test where the test specimen is subjected to > some standard number of watts of heat per square foot on the outside and > then temperatures are measured on the inside. This represents the worst > case that military equipment will ever be stored at, in world's hottest > desert on the equator at 2PM or something similar. I doubt anybody on this > list will ever see these kinds of temperatures on the surface of a KR, > mainly because the outside of your KR is air-cooled, and there's insulating > foam just beneath them. > > I did some testing when I added my wing tips a couple of summers ago. The > ambient temps were right at 100F. It was 108F in my hangar with the giant > door open. I was curing the dark red paint on the bottom of the wings out > in the sun because I was in a hurry to finish up the plane for the > Airventure Cup Race the following weekend. Just for kicks I checked the > temperature of the skin with a non-contact thermometer, and the number I > got > off my paint was 158F, which is a far cry from that chart, which predicts > about 205F (see enclosed photo). Context of the chart matters. I leave a > thermometer inside of my dark red car during the summer and the highest > it's > ever seen was 135F, with windows rolled up tight. I also checked the > carbon > fiber tips while it was out in the sun curing (before primer and paint), > and > it was only 165F, again a long way from that chart's 240 degree prediction. > > The stuff I do with my time... > > Mark Langford > ML at N56ML.com > website at http://www.N56ML.com > -------------------------------------------------------- > _______________________________________________ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options > >
