Back to the OP. The oil should cure fine but it will be softer than the Tru-Oil. I have had oil over varnish scratch easily even after two years of curing. In that case it was a Slacum mix with wax in so that it has better rubbing properties, but the same can happen with BLO.
If you don't want to wait this long to find out how hard it gets I would recommend mixing some Tru-Oil with linseed to harden it slightly. Shellac is good too and aids in adhering to anything. Use Linseed oil from the health food section of the grocery store, it is refrigerated or get the art store type. Also use turpentine as a thinner instead of mineral spirits. The turps will polymerize with the oils the mineral oil just evaporates and makes the finish more porous.
RE: Armor All one of the main ingredients other than silicon is a polymerizer and plasticizer. I tried it once and am waiting to see how it ages. The only visual difference I could tell is a slight cloudiness. Finish feels hard and is fine after three years.
I forgot to mention that with the food grade oil I add both Japan and Cobalt drier to it. It has all the fats and waxes in it and is the slowest of all to dry. This is an advantage for the initial coats as it has more time to soak in but a disadvantage for the final coats. Another product I am liking is Stand Oil from the art section. This is linseed oil that has had oxygen bubble through which initiates the polymerization process. I add enough turps for rubbing consistency and this type oil dries faster and harder than plain oil.
Last edited by Tejano; 10/10/19.
