Thread: Mineral Oil - soaking chop boards

Evan, try here.

Many thanks. From having a bear of a time finding it, there is now a glut.

I bought the oil from foodgradeoils.com.au. 5 liters was $44.

My thoughts were toward grain raising. Everyone knows the agony of finish sanding to perfection, adding some finish and it becomes a ware-porcupine. It's all spikes and teeth.

The Russian guy soaks his for 6 hours, sometimes 8 dependent on the video. I was thinking this might be a decent thing to do with my salad bowls, but, I've never seen this in any book or video I've ever seen.

I use this http://www.ubeaut.com.au/FS+.htm

You might try preheating your kitchen oven to 325F.
Over the sink, slop the oil all over the boards, one at a time.
Figure out, right now, how you plan to get the board out of the oven and onto a wire cake rack to cool.
Because it is now slopped up with 325F oil.

Put the oiled board into the preheated oven for 3 minutes (by the clock.)
Charles' Law (gas Physics) predicts that the wood air will expand when heated.
I expect you to see air bubbles coming out of the end grain.
As the board cools, the remaining wood air contracts and sucks the oil down into the wood.
Be ready to paint on dabs of more oil on drying places. .. .. . then wipe off the excess with paper towel.
Possibly a couple of years from now, do it again.

Raised grain? Probably not much. If any, polish it dow with a brown paper bag
or brown box cardboard (wood carving/finishing trick.)

I've done about 70 kitchen prep spoons and maybe 2 dozen kitchen prep forks this way (local birch wood = Betula papyrifera).
You will see illustrated threads about my kitchen sticks/tools in the Wood Carving & Sculpture Forum.

RV, that is an excellent tip. If the oil comes in tomorrow (today is a public holiday) I'll definitely give this a go.

325 F is 160 C ... Had to look that one up

You're most welcome. The objective is to actually replace some wood air with oil.
I use a soup bowl and a basting brush. Slop them up, onto the wire cake rack and into the oven.
With my double racks, I could finish a dozen spoons at a time. I use good olive oil.
Inside the wood, no fresh oxygen to react with the oil = does not go rancid (theory).

Trust me on this = more than 3 minutes and your wood will begin to cook like chips.

Here's the other thing: You could use boiling water to rinse off the boards.
At 100C, it isn't hot enough to get the remaining wood air expanding enough to push
the oil finish out of the wood.

You have no doubt seen how old wooden spoons are somewhat blackened?
Hot soup pushes the air, soup gets sucked into the wood and rots like the
bottom end of a composting bin. Yummy.

Wooden chopping board + cheap vacuum bag + lotsa' oil = unique selling point of 'pre-oiled by vacuum infusion' chopping boards.

"Oven-baked olive oil finish." Cannot be washed off.
It is a good selling point and a process which takes 3 minutes start to finish.
What really, really tested my patience was when shoppers would ask: "What do you use these for?"

For boards these days, I have a slab of bird's eye maple for bready things.
I couldn't see the point of attempting to coat/finish it with anything.
Set of 4 plastic sheets for meat & veg that go into the dishwasher.

The vacuum pump trick would produce the same result.
Thanks for the suggestion.
We did that a lot in the lab to perfuse the air space in pieces of green leaves with buffer solutions.
Generally took 3 or 4 pump outs and very, very slow returns to 1 atm pressure to get them to sink.
I've got a really good pump but can't remember who I lent it to.
RFE rotary, it could pull 10^2 Torr.

Has anyone seen veggie oil go "rancid"??? I have been using cheap cooking oil on my end grain boards for years, and none have gone rancid on me, whatever that means. How does it go rancid?

By far the worst thing for chopping boards seems to be onions. I just made a new chopping board recently with scrap tas oak, and used parafin oil and I cant tell the difference with my other boards.

Here's the difference between animal fats and vegetable oils:
They all fall into a category of biochemicals called triglycerides (by analysis).

Animal fats:
The long chains of carbon atoms are usually straight. Physically, that makes them easy to pack together
like a box of soda straws = they pack/solidify at room temperature and below. Very delicious to
bacteria, fungi and people.

Vegetable oils:
The long chains of carbon atoms commonly have one or more double bonds between pairs of carbon atoms.
Physically, those gnarly, bent and kinked shapes are very hard to pack together = they tend to roll around with eachother
at room temperature with a liquid appearance. They won't begin to solidify until maybe 5-6C and colder.

Atmospheric oxygen can get into and break the double bonds over very long periods of time.
This is a "drying" effect, some oils faster than others, as oil paint artists are well aware.
The broken products do not taste good, they do not smell good = rancid.

Using heat & Charles' Law, getting the veg oils well down into the wood, hides them from the atmosphere.
Therefore far less "damage".

I think that I would use walnut oil and not mineral oil. Mineral oil does not cure and eventually will "float" out of the wood. The walnut (Grocery store or woodworking store) oil sort of cures.

When I did cutting boards (Maple with cherry accents) for the kids, I applied walnut oil every day for a week and then once a week for a month or so. The kids refresh the finish once every 6 months on the dry board (Breads) and monthly on the wet (Meats) one.

I used olive oil on my kitchen tools because I wanted to use a finish that everybody
would recognize as "food." Any recognizable vegetable oil would be OK.
Mineral oil has never been one of my food groups.

Walnut oil would work very well.
Nobody can sell anything anymore which has been finished with peanut oil.

However, I need to carve a 5" x 12" dish which will sit by my kitchen sink.
Sink stoppers, pot scrub pads, veggie scrub brush, those sorts of things.
I'll do it in 6/4 birch and use mineral oil & the oven trick. Nothing fancy.

Isn't the very properties of mineral oil not curing or drying out one of its advantages?

Obviously it isn't "food" but incidental consumption isn't bad for you? It's not as if you're drinking the stuff!

Well, I bought a 500ml bottle of Mineral Oil at the local drug store (aka the Chemist's).
On the front label it says: "For relief of occasional constipation."

I suppose that if it did "cure", your constipational problem might be terminal.
Many people believe that I'm full-of-it, anyway.