I don't wanna totally hijack someone else's thread or really even argue but just say I have read a bit on the subject (google free books and other stuff) and while I think I understand what Shigo is saying, I disagree with him on a somewhat theological level.

Practically except in some cases like oaks and perhaps dogwoods the general public should be coating tree wounds I agree. But because we do not know what to use for sure not that it is not a sound idea.

After a wound has calloused over it seems I can do alot to a tree without hurting it. This includes just plum painting the exposed wood of a bradford to see if it rots slower than non painted bradford wood. Yes it does. BUT I can't really recommend leople do that because its not like I have access to a forest of trees to fool with for a decade.

So I am not being rude when I disagree. I am just in disagreement.