I shopped around, the typical RC shops stock Aluminum wing tubes in various sizes and lengths, but are pricey. I found an alternative by searching for thin walled aluminum tubing and found Onlinemetals.com. I ordered last Thursday and received them today. I ordered a .750 x.035, 1.00x.049 and 1.25x.035, all in 3 foot lengths and they are perfect. I test fitted them all after deburring the ends, and they all fit perfectly.

The one thing you can't get there are the sleeves, so you can either buy them from some other place or make your own if you need them.

The difference in cost was roughly $30, and that was with various lengths from the RC store, so they actually cost more than that when you do it by inch.

One other thing, for those who want to skin their plane with metal, they sell aluminum tape, 1000 series adhesive tape in .002 thickness on a 6" x 100' roll for $53. They also have stainless steel tape if you have a need for it.

If I bought the tubes from an RC shop it would have cost $73 plus shipping, for less than 36" pieces, mostly 24 - 32" in length, and for 3 pieces all 36" in length, with shipping spent just over $61.

http://www.onlinemetals.com/