impregnated with paint
is a very traditional way of sealing a wooden deck
. The technique is centuries old. Done properly and properly maintained a canvas deck is waterproof and quite attractive. It takes some skill and patience to do well and has a comparatively long lifespan, 10-15 years if properly maintained. Maintenance
includes painting every year or so, careful sanding
between coats so as to avoid sanding
the canvas itself.
A more permanent solution is to glass the decks using epoxy
and dynel cloth or epoxy
and F.G. cloth. If the deck fastenings are good, that can have a lifespan well in excess of 20 years or more.
If the canvas is in good shape there is no reason why you should simply sand and repaint the canvas.