By the way, if you plan on making lots of hoops, make yourself a hoop-forming template, then just go into fast manufacturing. Probably 3 minutes a hoop if you wish to have lots of them for many trucks. Or if perfect symmetry is important to you.
This is probably not worth the effort if you are only making hoops for one truck bed.
Note: it is recommended to finish with the compressed end of a top rail section. Then you can save the cut off the end and use that piecs on other projects and both ends of your finished hoop will be the same diameter.
This is probably not worth the effort if you are only making hoops for one truck bed.
- Make 2 identical hoops, weld them together, side by side. These need to be made to the right size to form the inside curvature size of the final product.
- Make another hoop slightly smaller, and weld it to the inside of the first two. TRICKY: if this isn't the right shape, you will not be able to change it much! I recommend a slightly smaller width at the ends than on the corners of the curve. After all, that metal is going to spring back to a slightly bigger shape just a little bit when you release the "forming" pressure.
- Weld a tube on the base of one leg, slightly larger than the diameter of your top rail. This becomes the anchor point for future hoops to be formed.
- Add a strut/brace across the two ends, just to make sure it doesn't flex too much.
- Anchor your new hoop-maker to something substantial. A truck bed with stake pockets works pretty well.
- Make new (but identical) hoops by dropping one end of a 21-foot top rail into the anchor point. Pull the other end around your hoop-form until you reach the other side.
- Cut off the excess length on the finishing side.
Note: it is recommended to finish with the compressed end of a top rail section. Then you can save the cut off the end and use that piecs on other projects and both ends of your finished hoop will be the same diameter.