I was a millwright for many years back in the 70s and 80s
We used a Devcon commercial product that had steel particles in it
It came in two cans of very unequal size with snap down lids like a paint can
The resin was gray/black and the hardener was translucent amber and looked like old time axle grease
Once hardened you could file it, sand it, grind it, machine it, and as long as you prepped the surface it was NOT coming off of there
You could rebuild a wallowed out keyway, use shim stock and release agent to build up a bearing surface on a conveyor shaft and it would hold until you could get a new shaft (or longer)
We used it for everything under the sun
I wish I knew if they still made the same product