: After painting a canvas kayak, I want to varnish it. What will I have to do
: to prepare it for repainting? Can I paint over the varnish?

Not sure that you will want to varnish over canvas, painted or otherwise. Varnish tends to be a rather brittle finish when hardened and the canvas will want to flex some. You may want to make a test panel, stretch it, paint it and add the varnish and allow to dry, then do some pushing and proding to see how it will hold up when flexed. ??? "Food for Thought"

Rehd