LancelowDowell

Well, the spruce is only 1/8". For the loads I'm going to be putting on this plane, that alone wouldn't have been enough, hence the carbon fiber. From my guesses, 5 g's would be a normal load for some moves, at worse case the airplane will weigh 20 lbs, so I need to be able to support 100 lbs roughly. For spruce alone, I would need a pretty hefty spar, which adds weight. That is the whole problem with the current wing. By cutting down the amount of spruce and adding cf, I just chopped a load of weight off. Whether a balsa/cf spar could support the weight of the plane the same as spruce... I dunno. I talked with several of the more experienced builders in my club and they all recommended going with a thinner spruce spar layered in cf. I guess if I get bored one day, I'll build up a second wing and use a balsa/cf spar to see if it makes any difference. My other biggest concern with the wing would be having it twist on me. I was hoping that using the bi-directional cf it would help reduce the twist at the spar, and it worked too. Whether it will help to keep the entire wing from twisting, I'll have to wait and find out.

But as for epoxy, how else are you going to do it? CA becomes brittle after time, I didn't want to spend the money nor risk my plane because of a bad ca bond. Epoxy, when done correctly, will hardly add any weight, and will give a stronger bond then ca can. We've had a few local guys come in to our club meetings and do vacuum bag wings that are fiberglass reinforced use the west system epoxy, and the result is incredible. Very light wings that are incredibly stiff. I also have a few guys in my club that build their planes with nothing but epoxy, and they are as light, if not lighter, then the guys using ca. It's all in how you use it....