***Yes flames should go on after the epoxy. If your thinking about having airbrush work done on your kayak it would be prudent to think about having an automotive clear coat sprayed on instead of varnish. #1 Automotive clear coating offers more UV protection which will make the paint color last longer especially if your thinking (red flames) the colour red tends to be one that fades fast in direct sunlight. #2 The clear coat is durable and looks very pretty it also adds depth to the wood, & or painted surface. We have had luck using the color shifting paint which you can spray on with an airisol can, using the blue automotive tape & masking off the area you don't want to paint. Follow the directions to the 'T' & ask about the time allowed between the differnt coats of colour paint, & or clear coat applications as you can end up with a snake skin appearance if the paint cures to fast. Good luck.***