"Christopher Tidy" wrote in message
...
Am Dienstag, 9. Februar 2016 22:32:21 UTC+1 schrieb Jim Wilkins:

Older heartwood vs younger sapwood?

Ah. Probably right. Good point.

The pieces of oak I'm making the antenna insulators out of came from a
slab off my sawmill, cut into narrow "stickers" to space the planks
apart while they dried. The boundary between soft sapwood and denser
heartwood runs diagonally across them it and gives me trouble clamping
and milling them.
--jsw