Wow, I thought we'd come up with a consensus pretty quickly on a basic salad bowl finish, but it seems that there are as many answers as there are issues.
- The issue I have with sunflower/olive/mineral oil is that they don't harden and therefore will wash off.
- Tung/Danish oils have added dryers (usually metallic) that may or may not be harmful to the user, depending on who you listen to, and can be quite smelly for a long time.
- So that leaves us with walnut oil, which is self polymerizing (it dries) in a fairly short time, days as opposed to weeks and therefore will (should) not wash out of the wood under normal use. I think I'll give some walnut oil from the supermarket a go and just hope that it doesn't go rancid, it shouldn't once it polymerizes, should it??
What we really need is a UK supplier of Mahoney's Walnut oil, it's what Mike himself as well as Glenn Lucas use, and they know a thing or two about making salad bowls in great quantities! Mike's oil is heat treated to ensure it polymerizes quicker.
http://www.bowlmakerinc.com/finishes.html
Here's a snippet from his site
"About Mahoney’s Utility Oil
Mahoney's Utility Oil is a heat-treated walnut oil used as a substitute for polymerized
(Danish oil) oils and mineral oils. It is the all-natural, food safe, and non-toxic choice for
your wood projects. Mahoney's Utility Oi1 penetrates the wood and then hardens, similar
to polymerized oils, but unlike mineral oil which never dries and eventually evaporates.
Although polymerized oils (boiled linseed oil, tung oil, etc) generally offer the greatest
durability for wooden items, they are toxic to the skin, emit an odor for weeks after
hardening, and science is inconclusive about their safety after all the hardening agents
have dissipated. Mahoney's Utility Oi1 is the perfect substitute for these products; it is
non-toxic, food safe, there is no offensive odor, and it provides a durable finish. Use
Mahoney's Utility Oil for all your utility wood items (bowls, butcher blocks, spoons,
trivets, etc.). Mahoney's Utility Oil also works great on furniture with oil finishes."
http://poisondioxide.com/pdf/utility_oil.pdf
Cheers
Aled