Thank you for the input - I have seen the process you describe and it works great. The problem though is that for now I've only seen it with round tube, not square. The other drawback is that you have to have specially cut and formed tools, which for that process can be somewhat costly. I've spent the last week or so mulling over several different ideas, and I think I've finally arrived at a couple of conclusions regarding this project. One of those is that I should probably stick to something that I know well. While I know aluminum fabrication very well, I know composites even better. So, as of today (03/12/05) it looks like the airplane will be based on a composite structure however, the process to manufacture it will be very different from what we see in the industry today. There's still a few bugs to work out but it looks really promising, and I'm more sure of it working right the first time. The wings will most likely still be aluminum though.