What to coat wood tool holders

[f350ca]

Oak and walnut contain tannin, when moisture contacts the tannins you get tannic acid. If steel contacts green oak when sawing it you get an almost instant purple stain in the wood, in the cabinet shop a clamp in contact with water based glue gives the same purple stain in the wood and the clamp goes black.
If the cabinet is properly sealed and stays dry you'd be fine. But why take the risk.