Builders' Forum Archives
Re: Is This Worth It?
Posted by LeeG on Feb 14, 2005
it's not entirely for strength glass is used on the interior, it's to improve the strength of the waterproofing skin of epoxy, for a light person the wood is strong,it's the minor flexing of the wide bottom panels between the tape that allows for microcracks to open up and allow water to stain the wood. Pygmys original Queen Charlotte was like that, tape and no glass, CLCs CapeCharles the same, tape and no glass. Other s&g designers might recommend tape and no glass. The problem is that once the span between the chines and keel is wide enough the bottom will flex. Not flexing to failure but flexing that thin plywood is capable of. If it flexes enough to break the seal coat,,you get black ick. Something as mundane as moving the kayak around on a rack, stacking one kayak against another, or sitting on the kayak on an uneven surface that can make the cockpit panels flex a little bit. My first s&g was a Patuxent 17, built as instructed with 6oz on the exterior, TWO layers of 3" 9oz tape on the chines/keel in the cockpit. Compared to the Queen Charlotte and Chesapeake it had narrower bottom panels with less flexing possible in the bottom panels. It developed waterstaining cracks parallel to the wood grain in the cockpit.
For a light person the major reason is to prevent black ick over time. Thick fill coats could help but why not put in some cloth that weighs next to nothing?
In Response to: Is This Worth It? by Mac on Feb 14, 2005