In a recent woodworking class, we made some kitchen implements (spoons, cutting board, etc.). I assumed that the proper finish would be mineral oil, walnut oil, or some other penetrating oil with no rancidity problems. I was surprised when the instructor recommended tung oil, as it’s toxic when ingested.
What say you, fellow wood butchers?
I wouldn’t use tung oil on kitchen utensils. First of all, it’s hard to get actual tung oil, it’s usually a mix of oils. It does dry to a hard finish, but there are several products designed for food handling surfaces.
ETA: Here in the wiki it indicates the major problem with Tung oil is food allergies.
One question, though. Were you making spoons, cutting boards and so forth meant to be actually used, or just for decoration? (I made a cutting board in high school shop class, but as we only had pine in the wood shop, I was told that it shouldn’t be used.)
They’re to be used, although I’ll likely just use the board as a serving tray for cheeses and the like. It’s a combination of laminated beech and mahogany.
I’m pretty sure I can get pure tung oil here, but it usually needs to be diluted with naptha or some other spirit before using (as it’s so thick), which would seem to defeat the notion of it being non-toxic. I hadn’t thought about the nut allergy thing. I’m leaning toward just using mineral oil on the tools (which are cherry); the finish won’t be as pretty, but I’d worry about it leaching into any hot foods.
Flaxseed oil is just food grade linseed oil, it also dries to a nice finish without the worries.
ETA: remember to not wad up the oil soaked rags
I wouldn’t personally use mineral oil, since it doesn’t polymerize and always feels greasy to me. Walnut oil and flaxseed oil will polymerize and lose that greasy feel.
“Tried and True” oil finish is a heat-treated (not “boiled”) linseed oil that has no heavy metal driers or solvents in it; I’ve used it on furniture before. It’s a wiping finish - it’s thick as honey, each coat has to be rubbed off aggressively after it has penetrated, and it dries slowly (like 24-36 hrs per coat), but it smells great and you could drink it if you were so inclined.
Personally I think the concern about food-safety of finishes is a bit overdone. If the finish is truly cured before use, given the short amount of time that food is in contact with the wood I wouldn’t sweat it too much.