The New Steel Frame
I redesigned the new frame to save a future owner the same troubles the original had caused, and added enough length to the tongue to prevent those nasty dents caused by turning too sharply.
The old frame was made from two "c" sections of steel spot welded together, okay for strength, but a poor design that held moisture.
The new frame was wire wheeled,cleaned well with solvent, and received 4 coats of paint.
I had a friend who is a certified welder build the frame, taking much care in leaving no openings for moisture to get in.
The old frame also relied on a 2 x 4 for the outside support, we went with the same plan, but added an 1/8" plate around the outside for extra rigidity, then bolted a treated, and well painted 2 x 4 to the plate.