: Just some tests. i ran a few pieces of 12 gauge, as I recall,
: through the sewing machine at my usual 2 or 2.5mm stitch length,
: (10 to 12 stitches per inch) same as I use for light fabric. No
: tearing problems at all. The stuff is not brittle like acetate,
: and the punctures don't seem to act as starting points for
: tearing. Now this was fresh material. I know that as vinyl ages
: it will get brittle, and the holes will eventually become the
: spots where rips and tears will start--but that is how things
: age. For thick materials I'd still go with a wider stitch, so it
: doesn't weaken the material too much, like perforations.

: I have not made any significant projects from sewn vinyl. All the
: things I've wanted were glued so they would be either airtight,
: or waterproof. I do see a lot of sewn vinyl pouches for shop
: tickets in truck shops. I'd make one, but I never needed a vinyl
: pouch like that.

: Perhaps you will remember from your childhood how everyone would
: get a new sofa, and then have vinyl covers made for it. Turned a
: nice piece of furniture into a hot and sticky piece of
: furniture, b mil or but I guess we were messy children and the
: adults wanted to preserve the fabric as long as they could.
: Those vinyl covers were the same material, but a lighter gauge,
: maybe 6mil or even 8 mils thick; they were sewn, and they held
: up very well to all sorts of childhood abuse. then as the kids
: go older, and the vinyl did, too, it got grungy and was taken
: off, finally exposing the real upholstery fabric on the family
: sofa. this is probbly the reason why the vinyl material is still
: sold in the upholstery-fabrics area at the fabric stores.

: The thicker clear vinyl is used extensively on motorboats for
: windshields and windows. It is sewn into the fabric tops (Bimini
: tops?) that can be raised on cabin-less boats for protection
: from sun and rain. The life on it is something like 5 to 7
: years, I believe.

: The upholstery material used for seat cushions on boats is also
: vinyl, and the "reinforcing" in it is weaker than
: cheesecloth. It has a softer feel, and I suspect that it is not
: as dense as the clear vinyl. I've used that for battery holders
: and cases for photo equipment. My last significant vinyl project
: was a new seat cover for a Honda scooter. It wears quite well as
: a cycle seat, and since you have bikes, you can appreciate the
: amount of abuse vinyl sewn to vinyl can absorb. If the vinyl
: itself is not cut, those cycle seats tend to last until the
: thread rots out. Sometimes the vinyl is still flexible enough
: that they can be resewn. I made a posing stool for my studio
: with a sewn vinyl top in 1980. I keep it in the woodshop now. It
: is still in good shape 31 years later. In my experience, the
: stuff holds up, and stitching will not significantly weaken it.

: Try putting in about 10 stitches and give it a tug. You'll be
: amazed. The more stitches the better any force is shared. One
: single stitch might pull through with little effort--same as a
: single stitch in any fabric. But there is strength in numbers.
: Again, a wide stitch would be my choice.

: Biggest problem with sewing it to itself is that it is a slippery
: material and the feed dogs on the sewing machine, as well as the
: pressure plate, might need to be adjusted so that the vinyl
: feeds evenly.

: It is inexpensive material. My advice to anyone would be: Buy a
: couple feet and try working with it before you commit to a big
: project.

: PGJ

Can't very well machine sew it on the kayak, going to have to be sewn by hand, it's a different stitch, not a lock stitch like a machine. (I hate having to know about sewing ) Usually with boat tops there is fabric on both sides trapping the vinyl between them, the fabric for awile at least keeps the stitching from pulling on the vinyl, as it ages though you'll see where the holes get bigger and the vinyl sags.

I'd think gluing the vinyl would be the way to go.

Bill H.