Rotting Apple Tree

I decided this year I wanted to try and Air-Layer a part of the old apple tree in my yard. This tree is going to be removed eventually due to it having a rotting trunk. I was curious, if that rot will matter on air layering? The branch I picked seams healthy throughout it, but now I'm wondering if the problems of the larger tree will forbid the air-layer portion from being a healthy bonsai?
Pictures of the tree-Rot I'm talking about, I believe it was caused by a nail someone placed in a nook of the tree, The tree is otherwise healthy and growing.


The branch I chose to air-layer.

My understanding (could be wrong!) is that trees are able to ringfence damage and infections to a large extent, so if the chosen branch appears healthy now there's no reason for it not to remain so. Hope this works for you - I have 2 airlayer projects just started, Yew and Privet, keeping fingers crossed for these

Dave

Apple wood will rot out quickly if not treated... I have 2 that were dug from a garden to start life as bonsai, 3 yrs later when removed from my garden after recovering, the trunks were full of dry rot & once cleaned out completely hollow, it has had no negative effect on the health, with both trees growing & flowering strongly over the last few years since going into pots.