Ahem... there is ONE time that you use linseed oilicon on metal...!

This is when you are finishing damascus barrels using the old rust brown method.. Once you have been around the coat, damp and card off buoy a few times you dunk the barrel into a solution of logwood to darken the stain. After finally drying off the barrel, the traditional last finish is boiled linseed oilicon! This has the effect of filling the pores in the barrel and stopping any moisture getting in. It also smooths off the slightly rough finish and leave a nice shiny effect. It must be let alone to set for a week or so, and then can be oiled in the usual manner...!