Back in the day I used the massy finish of two ton epoxy dissolved in acetone, it was the most bullet proof finish I have ever used.
I used it on arrows as well and could lose one under the grass, find it 6 months later and find the feathers might be gone but the arrow shaft was like new.
This finish takes awhile to put on, one quick coat at a time before the acetone evaporates, what you mix up wil go bad in a week or so.
I am not as dedicated as I once was, I use tru-oil now.