How to tie a Roman Helmet?

[Gobae]

Other oils though like mineral oil are fine? Whats the problem with vegetable?

In addition to what Magnus said about vegetable oil going rancid, it also gets sticky and often times yellows as it's aging.

Someone mentioned a caveat about petroleum oils and leather. Now, I've not had any problems with that, but it got me to thinking that maybe neet's foot oil or lanolin might do both the leather and metal acceptably? Don't know, never tried it, just a thought.