Why is 6x2 square tubing so dang hard to find? Never seen anyone here use 2x4 for bumper building. Channel is strong but I want to build a bumper off PWagon plans. I feel at times banging my head on the wall cause I do not want to spend $170 for 20 ft stick of 6x2 and have over 12 foot left taking valuable space up and rusting away. So anything I can do to over come this problem?