I have a cedar strip canoe that is fiberglassed with epoxy resin. Over that are a few coats of varnish. I’m thinking about painting the inside of the boat a dark red because the epoxy didnt cure right and is cloudy. I don’t want to sand through the varnish if I dont have to.
1) Is there anything I can paint directly over the varnish or do I have to sand down to the epoxy?
2) If I have to sand through the varnish, how do I know when I’m down to epoxy? or do I just sand down to the glass?