Builders' Forum Archives
Re: Why glass the deck?
Posted by LeeG on Jul 6, 2004
James, the "issue" of glassing decks makes a association but not precise correlation to adequate deck strength. I made a Ch16 that didn't have deck glass, to "save weight" but added sufficient under deck reinforcements at the aft deck to handle standard conventional rescues. All I did was put a patch of 6oz glass under the aft deck between the hatch hole and aft bulkead with another 4mm strip on the forward edge of the hatch hole,,this was before the existing hatch rings. Those reinforcements added a few ozs to the kayak.
In MikeW. case adding 4oz deck glass would probably not have prevented the deck from breaking at the hatch reinforcement strip,,it probably would have prevented the long crack along the sheer. If you're building from the existing plans with the extra hatch hole reinforcements 4oz deck glass would not have as significant affect on aft deck strength compared to the extensive wood reinforcment around the hatch hole and ensuring that the hatch hole wasn't located too close to the cockpit. Previous to those extra rings that added 8mm of ply one could crack the deck at the edge of the hatch hole where it was only 4mm ply just by jamming in/out a big dry bag. If you're heavy, a beginning paddler intending on practicing rescues and didn't want to use 4oz deck glass for the durability it adds to okoume and exposed edge grain plywood on the sheer (that can suck up moisture like a sponge at any break in the epoxy coat) it would still be worthwhile to add some cloth under the aft deck between the aft bulkhead and aft hatch (which should be 10"+ away from the coaming). The most significant utility for 4oz deck glass is to provide surface durability so that the wood still looks attractive under 4coats of varnish after 10,000's of deck whackings (most people who paddle a lot put the paddle near the hull when initiating a forward stroke and every once in awhile you hit the edge of the deck) or sheer dinging that can occur in normal handling.
In Response to: Why glass the deck? by James Williams on Jul 3, 2004