Thanks for all the kind words. I’m fortunate to live in SF Bay Area in CA, so humidity is not a problem. I wrap the handles with Saran wrap after oiling. So far the ones with cracks haven’t gotten longer or wider.

Dan Snyder
RKCC CM-155

Oiling versus waxing?

While ivory is somewhat porous, given that it has a grain structure and has water content that varies depending on conditions, I suspect that it does not absorb any oil or other things used to keep it from cracking.

Oil molecules might be too large to absorb into it, but might coat the surface and seal pores insofar as it is not completely wiped off.

The same effect could be achieved by coating it with Ren Wax or carnauba wax, and polishing to leave a very thin coat.

I think everybody here appreciates that ivory is similar to wood in that it can absorb and lose water content depending variations in humidity and temperature and on how dense it is and the exposure of the grain.

And also that the inherent tension in the grain structure can lead to the releasing of that tension depending on how it is cut and shaped. Relatively "green" ivory would be more likely to crack than aged ivory. But even a very old uncut tusk might result in pieces that crack once they are cut and shaped and exposed to new humidity and temperature conditions. And also because stresses that were constrained and stable in the uncut tusk are freed up to start relaxing.

Just thinking out loud about it, and considering that I don't have ivory on any knives made after the mid-1800's. And for some reason I get away with storing them under normal conditions without any cracks happening.

Just lucky I guess.

Larry