Fill a hole in a tree

Question

Where a big branch comes off of the trunk of a large oak, there is a hole that fills up with water and debris. What can I do about it? I’m afraid it’s going to rot and the branch will eventually fall

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Answer 1

I've seen that filling with hole with some expanding foam, like I'd use for a hole in the wall of my home, would that be beneficial for my concern?

Answer 2

This article will help you.

https://www.gardeningknowhow.com/ornamental/trees/tgen/patching-tree-hole.htm