Rain Bags

The market for a decent glider rain bag seems to be either word-of-mouth underground-ish or they cost a small fortune and either don't have a zipper or leak profusely. With a 22+ hour drive to Florida coming up I set out to tackle making my own rain bag for my Sport. I ordered the vinyl, waterproof zipper and parts, and the cement to fuse the zipper to said vinyl. I flatter myself to think I have the skills since I've been quilting and making bags and such for years. Whether my little quilting machine is up to the task is another story.

Sail loft

 I certainly have the room for it upstairs, the loft is perfect at 24' long with a nice flat floor to work on and outlets out the wazoo for the machine and heat gun. The first order of business was to cut down the 18'x54" roll of vinyl that I ordered. I figured I'd make it easy and steal WW's measurements off the glider bag and add an inch for room.. wrong. I discovered they taper their bags thicker in the middle and smaller on each end. Not an option to cut the material down the same, it would pucker the zipper.

Cut to size

I ended up cutting a rectangular piece, and will have to get creative heat welding and try to take in the material on each side afterwards. I would rather the zipper go on flat.. which brings me to my next issue..

The ultimate PITA with any sewing project.. zippers. And not just any zippers, a waterproof, rubber coated, 16' long zipper..

..The zipper. Ah, yes. The biggest PITA of any sewing project. Per the hanggliding.org post I was following, I had to rough the rubber coating off both sides in order for the cement to adhere it to the vinyl securely, which was painstaking. It was an hour with the Dremel to rough it up. And that's about the end of where any of the instructions applied. It took me an hour to get one side glued and pressed on. And I'm not super happy with it, keeping an exact 1/8" of spacing up the entire run was damn near impossible. The next course of action is to cement the other side on, give it an hour or so to dry, and run both through the sewing machine for more strength. This will be introducing holes into the waterproof fabric, so another layer of cement or vinyl melted tape inside the bag is needed to seal it back up. But as far as structural integrity, I'd much rather have it sewn together than glued. Necessary? Probably not. But I'm an enginere... enginneer...uh..  I'm good a math. The heat-welding-only isn't an option with higher grade backed marine vinyl, which is what I'm using, because it only melts the face together. It scorches the backside of the material so it'll only weld if it's face-to-face. I haven't attempted to heat weld vinyl, ever. So that should be interesting. It'll either work gloriously and seal the ends together or I'll end up with melted blobs of crap on my nice oak floors. We'll see..
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The Conclusion:

It took me three days of crawling around on the floor but the bag is finished! Some hard lessons were learned after having to rip 16ft of threads out one by one. I tried just stitching the zipper on one side to save a few minutes rather than cementing it like the other- the zip ended up getting bunched and was 6" shorter on one side so the bag zipped in a spiral. No good, over an hour of 'ctrl+alt+del'. This was the prototype and I learned quite a bit though for future rain bags.

Zipper re-do with cement and presser

I prettied the ends up and still need to heat-weld the seams together to permanently fuse it. I will also go over all of the stitch holes with cement and vinyl melt tape to seal it up and add handles at the CG point.

Besides adding the handles and sealing the ends up, the bag is done!

The amount of waterproofing remains to be seen. The vinyl is 100% waterproof marine-grade, the zipper is 'water resistant' and doesn't perform well when it gets bent heavily. The tie down spots may be an issue so to remedy that I may end up putting a storm flap inside the next bags, although that would create it's own issues. I ordered materials to make two more bags for another Sport 135 and Ilya's Sport 155 (guinea pig #2). With the amount of requests I've had from pilots to have bags made, I may end up having to get the 'spensive industrial sewing machine I've been eyeing. My poor little quilting machine isn't happy..