Thought I'd share my experience with a Speedy Stitcher and some seat belt straps. I was originally going to go with grommets, but 90% of the kits had very light duty grommets. They are very thin and some reviews said that it left an exposed edge and would deform under moderate tension. I picked up a bosch grommet kit from Lowes just to check it out and found out right away that it was not up to task. Some of the grommets were even deformed sitting in the package, these things were paper thin. I then looked for the rolled rim grommets online which had the tooth lock or spur washers, which would be higher quality, and heavier duty, but couldn't find a kit. It was even more confusing when I tried to purchase the punch/die and grommets separately, and found out that the hole/die sizes are different between the different styles of grommets.
I purchased the straps from here
https://www.strapworks.com/Polyester_Seatbelt_Webbing_p/sbpew2ncf.htmA sewing awl can be found for as little as $7 at Harbor Freight.
I also grabbed some black braided poly thread, size 346 Waxed, which is pretty thick.
I opted for the Speedy Stitcher kit for $30, one in particular said that it had two large needles and two thinner needles. Not sure if the thinner needles in this kit would work better, but turns out I either clicked the wrong link or they changed the description, as it only had large needles. The large needles worked fine, and the 346 barely fits through the eye of the larger needles.
I've read that people had pretty good luck with sewing/awning/upholstery shops getting the job done for around $20 or so, but I couldn't find any business locally that could give me an idea on cost, and the couple that did said it would probably be $100 or more.
I would have probably just taken it to a shop to have it done had I known how long it would take to make all of the stitches, but I was already deep into the job when I had come to the realization, so I just kept going. I'm also going to be using the awl on a couple other projects, and I got much, much faster once I figured out a few tricks and got into a groove. Hard to say exactly how much time it took me, as I only worked on it here and there throughout the week, but if I had to guess, it took about 6 hours total. If I were to do it a 2nd time after what I've learned, probably half that time.
The fabrication....
At the front of the straps, I made a 1/2" loops so that I could run some line though to strap items onto the boat, the straps were stitched to the tramp at the same location as the oem stitching, utilizing the reinforcement material which was still on the underside of the tramp. At the rear end of the strap, I made a 1/2" loop but did not stitch the strap to the tramp, but instead just stitched the strap layers together so that I could use line to adjust the tension of the straps which will run through the loop and tie to the rear grommet holes. I then stitched a retention strap in the center of the tramp which will hold the strap down, but allows it to move freely. For the retention strap stitching, I stitched two lines with a zig zag pattern between on these, for the other connections, I used a box stitch
https://www.youtube.com/watch?v=wf6buu7PqT4&t=276s.
I will provide some photos later, I think it turned out pretty good, I guess time will tell how well they hold up.