A few years ago I found a fallen yellow birch on the woodlot that was quite rotten. I wish I had more available but this is the only time I have found a tree where the sapwood was spalted so cleanly and only the sapwood. I saved a cut-off and roughed two punky bowls. Even after drying the wood was too punky to cut cleanly, even with a sharp continental forged gouge. I saturated it with four ounces of 5cp CA glue and let it set a day. It was finally susceptible to fine cuts. Sanded to 600 grit, then sealed with Deft lacquer, followed with 4/0 steel wool. 7x5.25
I titled this Natures Pyrography, as my first impression was it was a burned pattern that I wish I had produced.
I have tried pyrography a few times with less than spectacular results. If I had more of this I would put my burner away for good!