I'm not sure what other board to post this on, but I have a question about trees. Oak trees to be exact.

I do a lot of stuff with calligraphy as a hobby, and there's this really old oak tree on my property (it's at least 150 years old because my great-great-etc.-grandfather wrote about it in a diary entry once). I wanted to cut away an area of bark from it and use a woodburning pen to write down a segment of "Beowulf" on it, in the original Old English. It would be from his fight with Grendel.

Basically I want to know whether or not this will kill or seriously harm the tree or if it should be fine. The area in question would be about 18"x30". I'll be writing it in Carolingian minuscule if anyone is curious.