ORIGINAL: prr6100
Find a friend with a lathe, buy a wooden dowel larger than the inside diameter of the aluminum tube, then ask him to turn it down so that is a tight fit in the tube. Slide or pound the wooden dowel into the tube, this will help staighten and fix the problem
Why would you do this? Yes it would be stronger, but it would also be 4x heavier for very little strength gain. Not needed. If you want to strengthen an aluminum tube then take some 3mm ply wood and rip a piece to fit in the tube, then orient the tub so that the plywood is vertical, bam, way less weight and way more strength along the proper axis. No need to make a carbon tube stronger.