That's an excellent question and certanly deserves an answer. Next question. please! You'll get a lot of different answers here. Pro and con for glass. I'm on the pro side. It adds very little weight compared to the strength and abrasion resistance it offers the deck. If you were going for an ultralight build you would want to leave the glass off, make sure all the fillets are as small as possible, pull the ring nails after the deck is installed, etc. But you're building a CH 17 touring kayak. It might need to stand up to some abuse!

George K

I built a 17 and an 18 about 12 years ago.  The original plans did not call for glass on the decks.  I still have both boats and have had no problems and they are still beautiful.  Shop kept of course!  I did drop a drill on the 17 and the bit punctured my beautiful varnish, clear through!  LOL, a freak accident!

I agree with George K.  Also, not all plywood is created equal.  Some (for example, Douglas Fir) have a tendency to surface check (small cracks that make the surface look like fish scales) after a few years, even with an epoxy coating.  Your forward deck has a bend that will allow the outer surface to check more easily than a flat surface.  Research the type of plywood you used for your deck.  If it tends to check over time, you should seriously consider a lightweight fiberglass covering to prevent checking in the future.

I am currently pondering the same question.  My neighbor has built several Chesapeakes, and Pax kayaks and he has never glassed the decks on any of them. He doen't even glass the hulls, just the inside of the cockpit. This guy is champion sailor who has designed and built hundreds of sailboats many of which have won races so I am pretty sure he knows what he is doing.  I have paddled some of his kayaks and they are very light and very fast but i doubt they would stand up to any abuse. 

Just epoxy and varnish would encapsulate waterproof and protect your boat from the elements but a layer of glass would add some great textile streanght to your boat and like the above posts pionted out probley wouldnt add that much more weight, by giving it that rock hard shell on the outside certainly gives one peace of mind that your boat can take any knocks , breaking waves and you dont stress about strapping it to the car roof nice and tight.

cheers Locky