How do those idea sound to my fellow netters, Glenn Martin
Glenn, I am with Mark L, lots of time and weight. Sounds like you need to find some honeycomb cores for your wings if you want to go to this much trouble. The honeycomb would accomplish both things for you. The best preference for you in my opinion would be to use 3/16th or 1/4th thick Divinycell foam cores for your wing surfaces. It is light weight, has very high shear strength, and compressive strength compared to urethane foam. You could put a layer of cloth on the interior surface of it but you don't really need to do that with Divinycell foam. I have mentioned this before. I took a piece of urethane foam, Home Depot foam that some have used, and a piece of Divinycell foam that I have used building a Long Eze and a Defiant. I laid up a single layer of bidirectional cloth on all three. The urethane and HomeDepot insulation rigid foam both are extremely weak in shear strength. I was able to take a hold of the edge of the cured glass cloth and rip it right off of the foam with no effort at all. I could not tear the cloth off of the Divinycell foam. The difference in the 3 is MASSIVE!!!!!!!!!!!!!!! It does cost more to purchase Divinycell foam as compared to urethane but it will also cost a lot of money for the carbon fibre you are talking about laying down in the V-grooves. If you are so inclined to try Divinycell as a core for your wing surfaces, Divinycell's HT series was developed for aircraft cores. You could choose their HT50 which is 3.1 lb/ft3.. It has a 100psi compressive strength, 73 psi shear strength etc. You may have figured out by now that I am a huge fan of Divinycell foams. I have used and tested a lot of different kinds of foams in an attempt to find a cheap strong foam but I have given up and submitted to Divinycell, there just is Nothing better right now!! Get a small piece and test it for yourself as compared to other types of foam then you will agree with me. Just my opinion of course. Larry H.
