This is a new type of epoxy made by west systems for plastic,
marketed for kayak and canoe repairs. It will also harden in water.
THe products been on the market since July but just now showing up in
marine stores.

I used some this weekend to repair the corners of the late model
overhead AC duct and it worked out really well. If you've got some
plastic repairs I would highly recommend it. You can buy it a kit
form from West marine for about 20.00. It will will work with any of
the west systems fillers and can be tinted.

If anyone wants to see a picture I took some before I sanded it.

JFF

Here's what west systems has to say.

650-8 G/flex Epoxy
A toughened, versatile, liquid epoxy for permanent waterproof bonding
of fiberglass, ceramics, metals, plastics, damp and difficult-to-bond
woods. With a modulus of elasticity of 150,000 PSI, it is a bit more
flexible than standard epoxies and polyester, but much stiffer than
adhesive sealants. This gives G/flex the ability to make structural
bonds that can absorb the stress of expansion, contraction, shock and
vibration. It is ideal for bonding dissimilar materials. It can be
modified with West System fillers and additives, and used to wet-out
fiberglass tapes and fabrics. Mixed at a 1:1 ratio, G/flex gives you
45 minutes of working time at room temperature. It reaches an initial
cure in 7 to 10 hrs and full cure in 24 hrs. Click for more
information. (8 fl. oz. / 236 mL)

http://www.westsystem.com/