Dont burn anything in the glass, not good results, its a PITA, and has no protection whatsoever, pyrography gives amazing results and take some time and skill, you want that to have all the protection you can offer, everything you can do its best done under the glass, on wood. For other techniques on glass, since they would require a lot of varnish for protection, its worth to re-glass just over the drawing.

: Once I have the old varnish off, I would like to put a design on the kayak
: since I didn't do it when I first built it. Can I burn a design into the
: epoxy and fiberglass with a pyrography tool or should I just paint or
: paste a design on it and then varnish over it?

: I'm also getting delivery of a Pygmy Osprey Standard kit on Tuesday. Two
: projects at once, if you don't consider my 14' Great Auk for which I have
: the hull done but nothing else in a year. On the Osprey, I hope to burn a
: picture of an Osprey into the wood before I epoxy it.

: Charles Robinson