I guess I've been lucky with whatever I did in the skinning as I didn't mist while sewing, the basement is relatively dry, and even in our often humid Ontario summer the 12 oz nylon skin is not getting slack or wrinkled on or off the water. I just hauled the thing outside on a hot day, soaked it well with the hose, let it dry thoroughly and then varnished it the same day before any humidity got into the skin. Each thin coat followed on as soon as the previous coat was dry up to seven coats. Generally I followed exactly the direction in the Robert Morris book.

: You mean 'as long as there -is- excessive humidity' , don't you??

: I skinned at 70 deg f and maybe 70% rel hum as measured on a hygrometer. I
: kept misting the Dyson 8 oz nylon with a Windex bottle and sewed the cloth
: as tight as possible after pinning to the gunwales. Now any time the
: humidity is over whatever I skinned at it goes slack. But if the sun hits
: the skin it tightens up, even when being wetted while paddling. You used
: water based PU and I used oil based PU but that should produce the same
: results...

: If I ever do this again it will be after someone writes a definitive book on
: materials and coatings for kayaks!

: Still confused,
: Rich