9 June 2018 at 11:08 pm #548441
What finish would you use for e.g wooden bowls that are meant to use as food containers or for utensils made out of wood?14 June 2018 at 4:46 am #548536
For open containers I would recommend Walnut oil or linseed oil. These penetrate well and produce a deep, very tactile finish which highlights the grain. You will see mineral oil recommended but it is a petroleum product and does not “cure” or harden. The three oils which will permanently cure are walnut oil, tung oil, and linseed oil. All are plant oils, for food containers the walnut or linseed oil are probably best. Commercial “boiled linseed oil” contains metallic driers to speed curing. The limitations of these oils are that they cure slowly-you can apply a very thin coat every day or every other day for several days, wipe off any excess, and leave it open-needs oxygen to cure. With very light coats the oil will sink in-thick coats will feel very gummy. Just wipe it on, wipe it off. It does take several weeks to completely harden but can be used immediately. If the finish gets scratched or worn, just apply a new coat. It is not an extremely waterproof finish, but is durable-the traditional finish for gunstocks, which are exposed to harsh conditions. Linseed oil can be found in the grocery store as flax oil or flax seed oil. This is a beautiful, safe, and easily repaired finish for this use. I would not use linseed oil for enclosed containers such as canisters-enclosed it will not cure and you will be able to pick up the scent for a long time. In terms of film finishes shellac will work in this setting also-very safe, shellac used to be the coating for M&M’s candies and used to coat time release medication pills.20 June 2018 at 1:57 pm #548642
I would avoid using linseed because of the smell if you get oil on the inside of a container the smell will linger, I finish the inside of boxes that I’ve oiled with de-waxed shellac, same thing with drawers otherwise you can have a smell that lasts months or years.
mineral oil would be an ideal alternative.20 June 2018 at 3:06 pm #548645
thanks both for answering. How about Danish oil?20 June 2018 at 7:37 pm #548646
Pure tung oil is supposed to be a good food-safe finish. I have been using Watco salad bowl finish on my cutting boards–it is an oil that penetrates and makes the grain look great, but it also cures and has a nice sheen to it. You could also try walnut oil–it polymerizes. That all said, in my experience, with anything that is being used for food/food preparation, there is a maintenance factor and you will likely need to reapply from time to time to keep the item looking/performing its best.
I believe Danish oil is a mix of mineral spirits, tung oil and probably some other things. My gut says that, once cured (like most finishes) it is probably safe enough for contact with food. The warning would probably be that the finish is something that will likely chip/fracture over time so there is a small risk that someone may consume a tiny amount of it. I don’t think it’s poisonous, it’s just a risk factor to consider. So with that said, walnut oil has given me pretty good results on some of my turned projects and it does not greatly affect the color of the wood.
20 June 2018 at 10:22 pm #548648
- This reply was modified 1 year, 1 month ago by David B.
I’ve used pure tung oil on chopping boards and utelnsils, but there is the risk of nut allergies, although I’m not sure how real this really is? has there ever been a known case where someone had a reaction?
pure tung oil is very water resistant as well, gives an amazing depth to the wood after a few coats.23 August 2018 at 10:21 pm #550513
Some people with peanut allergies also react to tree nuts, but Tung has not been examined to my knowledge. One case of Tung ‘sensitivity’ is listed on pubmed, dated from 1952, so likely not very common.(plus the oil will be cured into the wood). I think one can be allergic to any tree or part thereof, but those individuals will likely avoid wood utensils. You could attach a label stating the finish, when selling or giving it away, to avoid all doubt.
.26 October 2018 at 11:15 pm #552845
I am paranoid about such things. I would likely go with olive oil. Yes, I hear it can go rancid. Still, I would rather worry about that. I’ve also heard that is what Roy Underhill uses. If he doesn’t worry about it going rancid, then neither will I.28 October 2018 at 1:34 am #552857
I’ve had an Italian friend complain that all olive oil in the USA smells and tastes rancid. I guess he is use to really fresh stuff.
Another oil you can coat salad bowls and such with is coconut oil. It doesn’t polymerize easily to my knowledge but it does have several advantages.
It is Extremely resistant to going rancid since it is about 50% Lauric acid, a medium chain saturated fatty acid found in breast and cow’s milk. I think it’s the most resistant vegetable oil and people use it in salads.
It is semi solid at room temperature but will liquify in your hand when you rub it on, making it easy to apply.
Most people with tree nut allergies or peanut allergies do fine with it, even though the FDA classifies it as a tree nut ( it’s a drupe or one seed fruit. The oil is pressed from the endocarp, the white stuff)
Unlike the polymerizing oils, there is nothing to flake off into your food. In this respect is acts more like mineral oil. You will have to Reapply regularly.
It smells and tastes great, but you probably won’t notice it in food in the small amounts you will rub on and wipe off. I’m sensitive to linseed oil – “boiled” which usually me(ans with metallic dryers added, or flax seed oil, so it is what I use. ( I’ve also mixed it with spar varnish to use as a wipe on varnish for tool handles)
And in the rare case it does go rancid in the jar, (I’m told) it It’ll be easy to tell because I will turn from the pure white color to an amber and smell bad. I’ve never had that happen even storing it on a cool dark shelf in my basement shop for 3 or 4 years. I’ve also read of mold developing on it, usually because a contaminant was added to the jar during use. I scoop out a small amount from the jar with a clean spoon so that doesn’t happen.
If any of those bad things happen, throw it out. You will wear or wash it off a bowl before the applied oil goes rancid.
Also, virgin or extra virgin coconut oil has an “ indefinite “ shelf life while refined coconut oil is said to have a much shorter shelf life measured in months.
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