: Since the subject came up, Tom, have you ever used an iron instead of a heat
: gun? How did it turn out?

I've never used an iron in place of a heat gun for "gluing" polyester core PVC.

I tried using an iron with no glue on PVC ( vinyl / polyester / vinyl) but
the heat was insufficient to melt the vinyl and create a "heat welded" seam.

With clear vinyl ( no cloth), which is a softer / low melt temperature vinyl
in my experience , an iron can be used for welding. I prefer stronger cloth
core vinyl (PVC) over unsupported clear vinyl for float bags and sponsons, so
I haven't taken the time to heat weld the clear plastic.

There are portable hand held PVC welding guns designed for heat sealing PVC.
They are higher wattage than normal heat guns, and use a wide / flattened tip
that concentrates the hot air "between" the two sections of PVC to achieve the
high temps needed for welding. This is followed up by a small roller to
complete the PVC to PVC bond ( no glue). I've not used one of these.... yet.
I'd much prefer to heat weld vs gluing if it proves a practical "homebuilder"
air bag solution.

Below are two portable PVC welders....

http://www.plasticweldingequipment.co.uk/trailer-curtain-marquee-repair-pvc-welding-kit-pr-16235.html

http://www.steinel.de/en/thermo_fuer_heimwerker/heissluftgeblaese/hl_1910_e_elektronic

Another option is to use heat sealable nylon as it can be welded with an iron.

With PVC, the elbow is PVC, as is the hose and twist valve. When all
components are the same material there are no "glue" compatibility issues.

See the attached glued PVC sponson pic.

Tom