Tung oil

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TLM

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In most vegetable oils there is some water included, about 2/1000 in rape seed oil and about 4/1000 olive oil. That water plays a part in many processes that can spoil the oil, by making the pH low enough most of that is prevented and citric acid is also an antioxidant besides olive oil with added lemon is pretty good.
 

Robson Valley

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The heat treatment uses Charles' Law of Gas Physics. There is next to no invocation of any chemistry. I've used the same principle to waterproof wooden dishes with beeswax.
 

Broch

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Jan 18, 2009
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As we've discussed on a number of previous occasions, man has used a combination of vegetable oil and beeswax for thousands of years. The relatively recent research into the antibacterial and antifungal properties of beeswax may well explain the thousands of years of successful use.

Most of the rest is just marketing :)
 

Paulm

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May 27, 2008
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As we've discussed on a number of previous occasions, man has used a combination of vegetable oil and beeswax for thousands of years. The relatively recent research into the antibacterial and antifungal properties of beeswax may well explain the thousands of years of successful use.

Most of the rest is just marketing :)
Although beeswax has a very low melting point and will leach out into hot food or liquids. Unlikely to do you harm though, beyond flavouring the food and leaving the wood needing retreatment :)
 

TLM

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Although beeswax has a very low melting point and will leach out into hot food or liquids. Unlikely to do you harm though, beyond flavouring the food and leaving the wood needing retreatment
Some people eat it, I have tasted it and it has just now taste so I don't think adding it to your whatever will have any effect.
 

Robson Valley

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Almost all biological waxes melt at temperatures close to 60C. The beeswax cannot leach out into food any more than the oil does.

I buy and eat comb honey. I like both the taste and the texture. The bees do not like to work the little wooden boxes. So as a premium commodity, the price goes up. Memories of my childhood, far away.

Here's the process. These are physical facts, not opinion.

Preheat the kitchen oven to 170C/340F or so. No hotter necessary.
On a mesh cake rack over a sheet pan, slather the wooden utensils, dishes, etc with oil or melted beeswax.
Into the oven for 3 minutes and 30 seconds by the clock. We aren't making chips.

OK. Out of the oven to cool, take a look:
Charles' Law predicts that heated air expands. Fact.
You see that as strings of little bubbles of wood air in the liquid oil/wax.

Charles' Law predicts that cooling air will contract. Fact.
So as the wood cools, the remaining wood air contracts and sucks the oil/wax down into the wood. Brush with more oil if you feel like it.

That's done for keeps. Boiling soup is approx 100C. That isn't hot enough to move the oil in the wood. Hot dish water can't move the oil finish.

As a note added in proof, many old wooden spoons are blackened from heating and sucking in food juices as they cool. Those decompose like the bottom of a compost box. It's just a physics trick you can take advantage of.

Here's an old pic of the production.
 

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Paulm

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So what is the point of using beeswax if it leaches out in hot food or liquids ? Why would you bother ?

Why would you not just use pure, polymerising tung, walnut or linseed oil instead ?

I honestly don't understand what folks have a problem with here, it's a well established, accepted and proven approach in handcrafted food related production, simple and effective.
 

Paulm

Full Member
May 27, 2008
1,089
183
Hants
Almost all biological waxes melt at temperatures close to 60C. The beeswax cannot leach out into food any more than the oil does.

I buy and eat comb honey. I like both the taste and the texture. The bees do not like to work the little wooden boxes. So as a premium commodity, the price goes up. Memories of my childhood, far away.

Here's the process. These are physical facts, not opinion.

Preheat the kitchen oven to 170C/340F or so. No hotter necessary.
On a mesh cake rack over a sheet pan, slather the wooden utensils, dishes, etc with oil or melted beeswax.
Into the oven for 3 minutes and 30 seconds by the clock. We aren't making chips.

OK. Out of the oven to cool, take a look:
Charles' Law predicts that heated air expands. Fact.
You see that as strings of little bubbles of wood air in the liquid oil/wax.

Charles' Law predicts that cooling air will contract. Fact.
So as the wood cools, the remaining wood air contracts and sucks the oil/wax down into the wood. Brush with more oil if you feel like it.

That's done for keeps. Boiling soup is approx 100C. That isn't hot enough to move the oil in the wood. Hot dish water can't move the oil finish.

As a note added in proof, many old wooden spoons are blackened from heating and sucking in food juices as they cool. Those decompose like the bottom of a compost box. It's just a physics trick you can take advantage of.

Here's an old pic of the production.
Oils don't leach out when they have polymerised, you seem to be unnecessarily complicating something very simple, don't know why :)
 
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Robson Valley

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They do not need to polymerize in less than 4 minutes. They don't polymerize like a plastic. When they oxidize very rapidly, you see a fire.
I don't see a pot of hot chip oil polymerize in 4 minutes. Charles' Law takes all the guess-work out of a fast and effective permanent finish for wooden kitchen utensils. No need to invoke any chemical reactions.
 

Robson Valley

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The central concept is Charles' Law. A slick little piece of physics that beats any and all room temperature superficial coatings.
If there are any chemical side effects in less than 4 minutes, they can be ignored as insignificant.
 

C_Claycomb

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I have had spoons that were treated with room temperature olive oil where the oil has left the wood. I have my own spoons where I have room temperature applied pure tung oil, no thinners, and allowed to polymerise and the oil has left the wood in some places, notably the end grain where the utensil meets the pan. Those areas have absorbed from the food cooked.

Pure tung is quite viscous, more so than linseed and way more so than the mixed blends that include thinners. As such it does not soak in very well at room temperature. I don't really want to use thinner on eating utensils, so using heat to thin the oil and encourage it to be drawn into the wood makes sense.

Oven heat applied tung oil....so far so good, but need more time to see how much difference it makes.
 

TLM

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Nov 16, 2019
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Did some searching on olive oil, it is fairly reactive just 14% saturated fatty acids. It apparently does leach out of the wood when not crosslinked or chemically bonded there, still not all of it, even hexane did not get all out. But the impregnation was done first vacuum and then 7.5 bar pressure so not really your standard home treatment. It does not easily crosslink without catalysts, cobalt octoate being one of the most common previously but now being phased out with other organometallics.

Looks like a fully crosslinked oil would be be your best bet. Some of the modern catalysts apparently are quite non toxic. Vacuum treatment would be way better than anything achieved with gas laws, though they have they place in achieving bubbles lacquer layers. Some terpenes might be used for thinning oil if heat is not enough, alcohols apparently do not work at room temp.
 

packalot

Member
Feb 18, 2020
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Alba
late to the party but i thought i might chip in with a little anecdotal info:

roughly 20 years ago i had a job that had me sitting in the woods for extended periods of time with not much to do but stay awake. i'd been curious about spoon carving so that's what i ended up doing for the duration. when it came to finishes i tried a bunch of things with mixed results:
  1. olive oil with a beeswax finish: lovely, nice feel, not particularly durable. needs frequent refinishing, every few months or so. pretty but not suitable for heavy use kitchenware. possible rancidity issues.
  2. olive oil and beeswax melt: here the idea was just warm it enough to melt turn the mix into a fluid and submerge the items in it for a spell, 30+ minutes or so. better than #1 by far but still not particularly durable. no rancidity issues though.
  3. pure tung oil (solo), multiple coats: great stuff if you let it cure for a good long while, a few weeks seemed to do it. durability was good, several months on a daily use kitchen item. bit of trouble with all but the most durable woods in that they tend to fray a bit around the hard-use edges and the pure tung doesn't do much to deal with that.
  4. pure tung (solo), saturation by submersion: here i'd let the item stew in the tung oil for a few weeks. items took longer to cure once they were out of the tung bath, 4ish weeks seemed typical. end results weren't significantly different than the above although there seemed to be deeper penetration and the commensurate lovely look that gave.
  5. pure tung + beeswax finish: this seemed to be the holy grail for totally non-toxic kitchenware finishing. multiple applications of tung OR full submersion if the project (and patience) allowed. this finish has lasted for decades on pretty much every suitable wood i tried including hard maple, yew, oak, magnolia, holly, apple, cherry, plum and hawthorn (my personal favourite). a yearly polish with warm beeswax keeps everything in top condition, also helps deal with whatever fraying of the wood might happen through usage (generally only on softer woods). these are daily use items -- cereal spoons, serving ladels, etc -- and their longevity has been nothing short of amazing. i have no clue why this particular treatment works so well but i suspect that the beeswax takes the brunt of the wear and tear and helps protect the tung underneath. just an educated guess.
 
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Toddy

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Jan 21, 2005
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I'm a housewife :) mostly, these days :)

I have a lot of wooden boards, platters, bowls, spoons and spatulas. Many have been made for me by family and friends, and I use them. I use them every day in life. Utensils are scrubbed under running water, and yes, I do use detergent. In the past folks just used washing soda or salt.

I don't 'ever' oil any of them.
I don't feel they need it.

The ends of spatulas, spurtles and spoons slowly soften and round over the years. The platters bleach slightly and become paler. Cutting boards are scrubbed under running water, wiped dry and set aside to air off properly. I don't use a cutting board for meat, but in my Mother and Grandmother's houses they scrubbed those boards with salt and washed them as I do.
Bowls are generally used for fruits or breads, and they just wipe out, occasionally given a good wash.
None of them are cracked or split.

Bread troughs of the past were not even scrubbed out, they were just used again and again. I've used some that were over a hundred years old and they still beat any modern bowl hands down :)

I have family pieces still in daily use that were made eighty years ago. My favourite rolling pin is made of sycamore. It was made over eighty years ago, it's still perfectly sound. Same with the big bread board.
Things like these have a life and wear and ageing is part of that.

I do use polish on the other woods in my home, a homemade mixture of real turpentine (a vastly different stuff from 'turps') beeswax and a little essential oil, usually orange.

If the piece is well made, with a crisp hand cut finish, it doesn't need the oiling. The sanded ones soften a bit more quickly, but if the timber is sound, they become 'right' too.
Oiling just comes out in the food anyway. I know the 'food safe' oils are supposedly edible, I also know that mineral oil is a pretty good way to skitter your insides though.

So for wooden utensils, etc., I'd say, use it, keep it clean, dry it well, unless it's just for show, and then you might as well use good polish or varnish it.

M
 

Robson Valley

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There is no room temperature wood treatment which can match the penetration that you will observe using Charles' Law of gas physics. Once done and cooled, you will be required to reheat the spoon to 325F or more to get that oil to move. No, it doesn't leach out as all room temperature finishes can be predicted to do.
The principle is not the oil that gets hot but the expansion and contraction of the wood air.
 

Robson Valley

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I wasn't interested in any finish that took a week. I was intent on carving kitchen tools to be sold in the weekly market.
Here is a sample:
 

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Robson Valley

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What can you do, adequately and inexpensively in your own home kitchen?
This is the correct concept when you are making wooden objects for sale.

10^-5 Torr is no improvement whatsoever.
I can get 10^-3Torr as I happen to own the junk to do it.
Huge PITA to try to treat the spoons that way. An hour to out-gas.
With Charles' Law, I am done and finished for keeps in less than 4 minutes.
 

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