Hi speed rotary bits and burnt cambium?

[wireme]

This is something I've wondered about. I've seen it claimed that high speed bits should not be used on live edges/cambium because the heat will burn it and it will die back further.
On the other hand I'm pretty sure I've seen a couple members here show approach graft grooves cut with a dremel successfully.
Is it just one of those things that is said to be but is not really based on fact?

 

[jeanluc83]

I don't know that I have ever heard that. I guess it would depend on what you are considering a high speed rotary bit. I use a round nose router bit in my Makita. The bit does heat up but it is a cutting action so I don't believe there is much heat going into the tree. I have seen bur bits but never used one. They might heat more because it is more of a grinding action than cutting.

The bark of the tree is made to stand up to heat to some extent. I don't think the heat from carving would do any significant damage.

I believe for any graft you want a clean cut. The cut you would get from a dremel is not that clean. I have not done any grafting so it might be good enough but I would imagine you would want something cleaner.

 

[Waltron]

my theory is that it will actually cauterize the wound and act kind of like a scab, happens when I cut the tap root under an old hard wood with my sawzall. My theory is based off a pure guess.

https://en.wikipedia.org/wiki/Cauterization

 

[wireme]

Thanks for the thoughts. I don't remember the source of that little tidbit, it was presented in a very assured manner like many things are. I have avoided touching the cambium with those tools since and use a sharp blade instead or after , not really a big deal, just curious.

 

[eferguson1974]

I never have carved a tree, yet. But I think it shouldnt be too much of a problem. Remember most trees can survive a forest fire. Thats pretty hot...maybe if you used an abrasive bit/tool, and left it in one spot on a hard type of wood it might get too hot.