I have been stuck with a similar problem on my stub wings. As my gear retracts into the stubs like a lancair and comes up very close to the top surface I need to make the top skins both strong for stepping on and thin (1/4" max). I have come up with the following plan. The areas ahead and aft of the spars will be standard but the area between the spars gets a special treatment. A foam core will be hotwired very accurately that fits between the spars. This core will be covered with cling wrap and then a layer of peelply with its edges taped to the sides of the core that will be in contact with the spars. After laying up the stubs in the conventional manner, the core is removed and the peelply carefully peeled away. A layer of 3mm coremat is then cut to fit the area between the spars and an extra layer or two of glass laid over that. This should be strong enough and probably no heavier than using the standard method. I might even do the outer wings like this. Regards Dene Collett KR2SRT builder South africa Whisper assembler See: www.whisperaircraft.com mailto: av...@telkomsa.net ----- Original Message ----- From: "Mark Langford" <n5...@hiwaay.net> To: "KRnet" <kr...@mylist.net> Sent: Saturday, January 06, 2007 02:32 Subject: Re: KR> balsa instead of foam
> Pete wrote: > > > I think you make those wings too heavy, as you will have to make it > > quite thick, or you will not be able to sand it to shape.