: Have you tried this?? Sounds interesting.

No. I haven't needed float bags in my canoe. The cheapest commercial roll-top dry bags work fine to keep my gear dry on trips. You could try something like that for floatbags in a SOF, but they are not going to fit as well as ones which are tailored to size.

In his book on canvas covered boats George Putz suggests using pieces of precoated scrap material for patches. he suggests using rubber cement as a contact cement. The boy Scout design for folding kayaks uses contact cement for holding the canvas and plywood parts together. They report success with these materials being in the water, and on trips for a week. That should be more than enough time to get off the water!

As for wrapping the boat to get a size: That is a pretty conventional sewing idea. They make human-shaped sewing mannequins for fitting dresses and blouses, and the process with boats is much simpler, although we want something smaller than the form (the boat) which the fabric is wrapped around. So wrap it, and sew it smaller.

: I have made a couple of sets of vinyl float bags and just very
: disappointed. Being as careful as I can I half or more will have
: a small leak. I patch it get them air tight and eventually they
: develop another leak. Some leak very slowly but they still leak.

A small leak is fine. why do you ned them to be totally air tight. These are not balloons. if they have a slow leak and lose a gallon of air in an hour then should you capsize you have an hour to bail that last gallon out of your boat. If a perfect floatbag would keep 100 liters of water out of the boat, and a leaky one only keeps 96 out, then the difference is trivial.

Put them in a bit slack and they will still displace water which gets into the boat. Inflating them to any level of pressure could cause them to expand too much on a hot day.

: I have not done it yet but my next set(s) will be heat seal nylon.

If you have the material then this could be a fast way to make them. If you don't have heat seal nylon you can get a heat-fusible material like heat 'n' bond at Walmart or any sewing store. Platt Monfort uses that stuff for attaching the polyester material to the wood on his Geodesic Airolite boat designs. Works fine for him. Again, you can seal the polyester with whatever you used to seal the boat's skin. see www.gaboats.com for info on this.

Good luck with your floatbags.

PGJ