Glue selection: trying to put a plastic skeg on an inflatable.

Hi all--

I recently picked up from Craigslist a west marine inflatable kayak (K1; it's a re-branded sevylor rio) on a lark for napping in on small lakes.  It's a surprisingly fun time, but unsurprisingly is a zig-zagging mess while paddling. 

So I bought a skeg off of amazon, this thing:

http://www.amazon.com/Tracking-Integral-Mounting-Points-Watershed/dp/B00QUHLMBI/ref=sr_1_2?ie=UTF8&qid=1431473208&sr=8-2&keywords=skeg

And a tube of Marine Goop. 

Which never dried. 

After 7 days.

I noticed after-the-fact the Goop label says "product cures by evaporation", which leaves me thinking the air-tight area between the skeg plate and the rubberized vinyl of the kayak might make evaporation in the center of the bond impossible. 

So any idea about what I should try next?  Leaning towards 3M 5200 fast, but thought I'd check in with you guys first.

Thanks,

Ron

They make special 2-part glue for inflatable boats.  5200 will melt some plastics so use with great caution if you decide to go that route.

They make special 2-part glue for inflatable boats.  5200 will melt some plastics so use with great caution if you decide to go that route.

Thanks for the input!

It's led me to the g/flex epoxy.  Seems to be directly made for this application: will cure underwater, designed to bond lots of natural and synthetic materials (the NRS folks call it out for bonding PVC to Hypalon), remains somewhat flexible after curing, permanent.  Main drawback seems to be cost and UV sensitivity, but neither should be an issue (cost should be about $25-30, it's gonna be stored out of light nearly always).

This'll be the new leader of the pack, unless I get consul to the contrary.