Tung oil

[punkrockcaveman]

I'm going to buy some tung oil, I've seen some liberon stuff that's about a tenner for 250ml posted. They have a 'pure' tung oil and a 'quick dry' version, any idea which is better?

I'm leaning towards the quick dry as it will be used on cups, spoons and bowls for food, but I have no experience with tung oil

Cheers for any info

 

[Broch]

I checked the quick drying stuff some time ago to use on bowls to keep fruit in and it appeared fine for food stuffs. I think there are a few additives in it but nothing 'dangerous'. Of course, that may vary from one make to another. This is the stuff I was looking at and there's a full data sheet on it.

Quick Drying Tung Oil | Libéron woodcare

Really easy to apply : the Quick Drying Tung Oil by Libéron. Discover all our paints and wood products. Find tips and advice for all your renovation works

www.liberon.co.uk

I can't advise further as I never used it in the end.

 

[Paulm]

I've always avoided quick drying oils for food use, be it bolied linseed oil or quick drying tung oil.

In the case of boiled linseed oil the quick drying is caused by the addition of chemicals or solvents I believe and is not thought to be suitable for food use, certainly in all the spoon and bowl carving groups I frequent.

Haven't looked into the details of the quick drying tung oil specifically but would expect it to be similar,

The quick drying variants are generally used for finishing of furniture and the actual percentage of the oil they contain can be surprisingly low relative to other stuff.

I stick to pure walnut or tung oil myself for peace of mind

 

[Broch]

The full data sheet for the above oil shows nothing of concern at all but I do agree with you in general.

 

[Paulm]

The full data sheet for the above oil shows nothing of concern at all but I do agree with you in general.

The quick drying version contains ethyl methyl ketoxime, the pure tung oil doesn't, that brands data sheets show, other brands may well be similar.

A quick google came up with a research paper that showed health issues in rats tested with it, red blood cells, spleen and liver I think although I didn't read it fully and am not a scientist so don't know how that would translate to real world applications on food stuff.

I wouldn't worry about using it on fruit bowls for example, but I wouldn't use it myself on bowls or spoons for example that were going to be in prolonged contact with hot and/or liquid foods, but again not based on any scientific knowledge just me being cautious !

 

[Broch]

It's all down to the level of any chemical and the level in the product and it's not identified as a hazard on the datasheet at the concentrations of less than 2.5%. I had a look and very high repeated concentrations were used on experiments on rodents. In addition, it is a volatile liquid that will evaporate off as the oil hardens. Like most things, even water, it's toxic at high levels of ingestion

I think I would be happy using it on any utensil in contact with food, but then, I use spoons made from Holly (as we have in Wales for thousands of years)

 

[nitrambur]

Tung oil is a minefield
Here's what Stumpy Nubs has to say on the subject

 

[punkrockcaveman]

Thanks for all the advice gents, I went for the Liberon pure tung oil in the end

 

[AberSi]

Bit late to the thread I know, but I would give a recommendation for Osmo Oil. Having tried most oils/finishes for my projects, I've now switched to it for everything. It's a hardwax oil that's dead easy to apply (2 coats buffed in with a scourer/high grit paper). Goes off fairly quickly, food safe and has a lovely satin sheen finish.

 

[Paulm]

Bit late to the thread I know, but I would give a recommendation for Osmo Oil. Having tried most oils/finishes for my projects, I've now switched to it for everything. It's a hardwax oil that's dead easy to apply (2 coats buffed in with a scourer/high grit paper). Goes off fairly quickly, food safe and has a lovely satin sheen finish.

Wouldn't use this on bowls and spoons used for eating hot food from personally.

Being food safe in respect of kitchen worktops doesn't seem to me to naturally extend to eating your hot porridge or stew from it, on repeated occasions, with the possibility of substances leaching into your hot food or acidic dressings or sauces.

Have a look at the data sheets for it and see some of the additives and the section on personal care too.

Each to their own as always, but I would always suggest to folk that ask for advice to stick to pure tung, walnut or natural linseed oil, allergies allowing. They are unadulterated with artificial chemical additives and polymerise (harden) over time avoiding residual stickiness and possible rancidity if applied correctly.

I guess I just don't see any reason to take possible risks with other less natural products for these applications when the natural traditional ones that are already widely used in the food craft sectors work just fine

 

[Silverclaws2]

I hae always used Danish oil for wood projects.

Danish Oil I believe contains tung

 

[Robson Valley]

You have seen enough of my wood carving projects, many of which are bowls and dishes meant as food containers. I use MinWax Tung Oil Protective Finish which is quite Food Safe (like many others) when it has fully cured.
For the 70 spoons and 30 forks that I carved in birch, I took advantage of the principle of Charles' Law in gas physics to do an oven-baked olive oil finish in 3 minutes and 30 seconds. No, it can't be washed out. No, it can't go rancid, that's a myth.

 

[TLM]

oven-baked olive oil finish in 3 minutes and 30 seconds. No, it can't be washed out. No, it can't go rancid, that's a myth.

Once you get rid of the double bonds in the carbon chain I think oxygen's effects are greatly diminished.

 

[Paulm]

I hae always used Danish oil for wood projects.

Danish Oil I believe contains tung

It does, but lots of other chemicals and solvents too, much of which may evaporate during drying of course, but may leave residues all the same. May not matter for chopping your carrots on but wouldn't fancy eating hot liquid stuff from it on a regular basis.

 

[Paulm]

Once you get rid of the double bonds in the carbon chain I think oxygen's effects are greatly diminished.

Yes, baking it will change the properties, but raw olive oil can indeed go rancid over time, not always but can and does

 

[TLM]

but raw olive oil can indeed go rancid over time

Enough oxygen around and it will. In a closed bottle with little air space and some citric acid added it just takes a lot longer.

 

[Robson Valley]

Using Charles Law, I don't have to contend with atmospheric oxygen at all.
You can't cook it out, you can't wash it out and no, it can't oxidize down in the wood.

 

[TLM]

V1/T1=V2/T2 or something like that ...

 

[TLM]

it can't oxidize down in the wood.

Yes it can but very very slowly because there is so little of it. Though your heat treatment might prevent most of that by reacting the double bonds.

 

[Paulm]

Another view on the subject, very typical of those on special interest groups of folk that make wooden bowls and spoons etc for food use

what is the best oil for treating wood? - Robin Wood

I get asked a lot of questions about woodturning and what is the best oil for treating wood is one of the most common so I have written an article in answer

www.robin-wood.co.uk