Does anyone know what one can use to paint canvas (on a yak) to seal the weave? I starteed with a marine sandable filler (@ 22.00 a quart) and was only able to coat the top. Needing to do the bottom as well and a second coat for the entire yak, I sought out the bb here and tried using a combo of LINSEED OIL, OIL BASED PRIMER PAINT, AND TURPENTINE in 2/2/1 ratio. This recipe yeilds a watery broth that paints well but does not seal the gunwale seams of the canvas. I have been following Putz's book on Canvas Kayak building and he suggests adding chalk powder and extra dryer. The only chalk powder I can find is the type used in chalk lines (blue, orange..). Knowing that the recipe will take 2 weeks to dry (as per orders of the bb here) I am searching for advice as to thickening my recipe or biting the bullet and spending the $90.00 for a gallon of the sandable sealer that has a consistency of pancake batter. Advice for the poor would be appreciated muchly :o Thanks.... Brian