I’ve got a rm(plastic) Chatham 16 that had a very leaky day hatch and moderately leaky oval hatches. I fixed the day hatch with 1mm neoprene tape and am going to attempt using Lexcel for the oval hatches. It’s kind of odd,when removing the hatch frames there was no attachment of the sealant to the poly hull except for one dime sized patch. Evidently the sealant they’re using is capable of bonding to the poly. The VCP hatch frames had scratches as though someone had given a few swipes with some sandpaper but the hull was absolutely smooth,seems to me that running some sandpaper on the plastic would be more important since few things bond to it. Will report back on whether it works. If it doesn’t I’ll go straight to making a gasket with neoprene.
Lexcel works, no leaks.
Remove old black sealant, roughed up the plastic, thick bead of Lexcel, tighten screws just enough to seat the VCP hatch frame then back off a smidge. Next day when it’s cured tighten back down. I used fender washers under the side screws of the oval hatches but it probably matters more that the poly is roughed up and the bead is thick. Don’t overtighten or the vcp hatch can crack.
Big Atta Boy… 
the funny part
is that the VCP frame was roughed up but the slippery polyethelene kayak wasn’t. So someone at Necky knows about roughing up VCP frames so sealant will adhere better but someone attaching the frames with sealant to the more slippery polyhulls doesn’t. funny.
Overall feel of the boat
How do you like the boat?
My wife is getting more and more into kayaking and I think this might be a great choice: easy for me to find/demo it in South Florida, RM therefore more affordable.
Actually I will probably go with the 17, it is narrower but with a wider cockpit, thus we could both use the boat, I just can’t fit in the 16’s cockpit.
Since I bought my composite boat I’ve been avoiding some places that I used to paddle (some canals that lead to the Intracoastal Waterway that are very shallow in low tides with tons of oyster bars all around), I just don’t have the heart to put the composite boat in there, but with a poly hull it is another story.
I like it
Once I threw out the adjustable back band levers and the metal guides that reduced the coaming width to 14.25". The funny part is that the wider 16 has a narrower cockpit,I think Necky goofed since the coaming was already on the narrow side of things for a hull that really isn’t for smaller people. The 17 cockpit is perfect. For a smaller paddler an Avocet might be better.