Here's some ideas on making a roll bar, and yes you can make your own.
If you’ve ever wished that your buggy had a roll bar and wondered how hard it might be to build one, I thought I’d share my recent experiences on fabricating my first. I’ve had a long time dream of building a Deserter GS ever since I was 18 or so, or a really long time ago. After finding an affordable, although very rough GS chassis that was structurally inadequate although pretty straight, I decided to take on a complete chassis rebuild and that includes the pretty uniquely shaped roll bar for this car.
The good news is that the only special tool required was the pipe bender. These are readily available from many places including Harbor Freight and will cost you about $100 to get it to your door. The one I used was a 10 ton version and it handled the 1 ¼ in pipe I sourced from a local railing company with ease. The pipe was 0.120 in. wall thickness and the OD measured around 1 5/8 of an inch, just about perfect for the look I was after. Oh, by the way, you’ll need about 12 feet of this stuff to make one simple hoop style roll bar with no extra cross bracing.
Just so you know, there is a difference between “pipe” and “tubing”. I’m no expert, but a pipe bender works fine on pipe and will just ruin tubing. It has to do with the OD or outside diameters not being the same, or something like that. Anyway, the pipe benders have the correct parts to fit “pipe” and “tubing” is different and will just kink. I’d guess that you’d need a tubing bender or something if you went that route.
Now, there are many reasons to have a roll bar and extra protection is only one, but if that is at least part of your goal, I’d recommend using something heavier than a muffler gauge of steel and stick with something substantial. Since I would be using paint on mine, raw steel was fine. Another good choice would be starting with stainless steel, but I have no idea where to get that.
After a couple practice bends on some scrap pieces, I noticed that the bender would leave two dimples on the outside of the bend where the two rollers made contact! Since that would ruin the whole look, I needed a solution. It turned out to be pretty easy one also. I cut out a section of 1 ¾ inch plastic pipe to protect the roll bar at the contact points with the rollers. (see photos for an idea). As it turned out, this worked perfectly.