# yet another cutting board question



## Betsy (Sep 25, 2007)

I've done three or four end-grain boards and this is the first time I've had this happen.

When I oiled the board - I generously applied the oil on the top and did that until the oil dripped through the other side. Then when it made it to the other side - I flipped it over and applied oil to that side. I applied oil until it pooled and no longer absorbed. I allowed the board to dry for three days.

Then the issue set in. This board was for my bosses wife - so I took it to work for him. When I left the house it was fine and dry. The minute I stepped into the building the oil starting coming out. In fact, I leaned the board against the wall (laying on top of the chair mat) and within two hours I had a puddle (yes a puddle) of oil on the floor. It took another couple of days for the oil to stop seeping and for the board to dry.

Would like to know why this happened. My only thought is is that my house is much cooler than the office. When it hit the heat it had to equalize.

What do you all think?


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## CharlieM1958 (Nov 7, 2006)

My first thought was humidity. The office air was drier, so as water evaporated the wood cells shrunk and squeezed out the oil. But then I'm wondering if that would happen since the wood is saturated with oil anyway. I dunno. ;-(


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## teenagewoodworker (Jan 31, 2008)

what kind of oil was it. if it was mineral oil, mineral oil *never dries period*!

you need a good drying oil like general finishes salad bowl finish or Arm-R-Seal

remember that all finishes are food safe when cured so with oil wait about 2 weeks until use. because no finishes will dissolve inside your body except for shellac
-but every wonder what makes M&M's melt in your mouth not your hand (Shellac )


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## Betsy (Sep 25, 2007)

Charlie - that makes sense.

Dennis - never knew that about M&M's. The oil was walnut oil. (yes I checked there were no nut allergies - even though I don't think it's an issue.) I've always used walnut oil with no issues.


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## teenagewoodworker (Jan 31, 2008)

yep betsy. shellac is also how they make time release pills and why fruit is so shiny in the store. 
the problem is a combo of what i said and what Charlie said i think. the natural oils never really dry and the fluctuation in the temperature caused the cells to shrink squeezing out the oil. you want a drying oil. something that if you look in the ingredients you should see some kind of drier. like heavy metal driers. the reason why this probably didn't happen before is because you might have waited longer or the fluctuations were not as great. this gave the oil the chance to get gooey like the blo or oil you find on the rim of the can. all gooey but not dry. hope this helps.


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## CharlieM1958 (Nov 7, 2006)

Just for the record, walnut oil does harden eventually.


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## Betsy (Sep 25, 2007)

It all makes sense. I'm thinking I should have paid more attention in science class - but when I was in science class the world was still flat!

Thanks again.


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## childress (Sep 14, 2008)

What's even more interesting is how humidity works…When the air is heated, or hotter, it can hold more moisture, meaning more absolute humidity. So, moving it into a warmer environment would make the wood absorb more moisture (which is in th air) to reach EMC (equilibrium moisture content) I think you just put too much oil in it, and since it takes a long time for walnut oil to dry and when the wood started to acclimate to it's new environment, it decided to shed some moisture (which was the oil you put in it). just my thoughts.


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## MsDebbieP (Jan 4, 2007)

you gotta love our LumberJocks. Just never know what you'll learn!! 
(love the world was flat comment. lol)


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## CharlesNeil (Oct 21, 2007)

Great answer Denis and dead on …guys let go of the blo and all the old seeping oils, just isnt worth the issues….the old timers used them because they were the best they had, NOT because they were the best…Times have changed alot , and i can assure you if they were here today they would be using good oils…Waterlox, seal a cell, arm r seal , to name a few….these oils dry hard , protect, and are food safe…more expensive..yes… better…by a mile…Blo now days isnt even "boiled'...they throw some japan drier in raw oil and here ya go…not chastising here, just trying to help


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## cajunpen (Apr 9, 2007)

Darn, I was going to say what Charles Neil said - but he beat me to it ). I do like the Arm r Seal though. Did you give the boss the board or are you still waiting?


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## Betsy (Sep 25, 2007)

Thanks for all the insight.

Bill - yep gave him the board. Got a text message that it went over big.


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## hObOmOnk (Feb 6, 2007)

Note: The following products *DO NOT* contain any raw Oils:

Waterlox
GF Seal-A-Cell
GF Arm-R-Cell

The WaterLox products contain an tung-oil-modified resin, but no raw tung oil. Essentially, the oil has been "cooked" with the resin to produce an end product that is chemically different than a raw oil.

GF Seal-A-Cell is a solvent diluted urethane varnish.

GF Arm-T-Cell is a solvent diluted oil-modified resin.

Most so-called Danish Oils are mixtures of solvents, resins and raw oils, e.g.
Watco Danish Oil contains about 70% solvents with the rest of the ingredients being resin, linseed oil and vegetable oil. The tinted versions of the WatCo product usually contain some Gilsonite, an asphalt derivative.

GF Danish Oil has a similar composition to the Watco product.

Whereas, Tried & True Danish Oil is 100% Polymerized Linseed Oil - no solvent or resin.

Other forms of "Danish Oil" may contain a mixture of different kinds of oils, resins and solvents.
There is no regulation on the contents or composition of Danish Oil products.

The so-called drying oils, such as linseed, tung and walnut oils, actually "dry" by a process called polymerization when they come in contact with oxygen. If you soak wood with a drying oil, the outer layer will dry before the portion that has soaked into the wood. The results may remain gummy for a very long time.

Mineral oil, food grade, has long been used to treat cutting boards. It won't dry.
So called "Butcher Block" oils are usually nothing more than mineral oil.
Grandpa, a chef, rubbed his cutting boards with food grade paraffin wax.

Raw linseed oil (RLO), food grade from a health foods store or pharmacy, and food grade walnut oil can be used. Both will dry, but very slowly.

A food safe grade of real tung oil can be found. It dries quicker than RLO and walnut oil

Unless a finish is marked as food safe, it probably isn't. Additives and contaminates aren't a consideration for wood finishes that are not marketed as food safe, including shellac intended for wood finishing only.

I was a clinical chemist in a former life.


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## teenagewoodworker (Jan 31, 2008)

remember. all finishes are food safe when CURED. once they are cured they are food safe. every single one of them.


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## hObOmOnk (Feb 6, 2007)

teenagewoodworker said: "remember. all finishes are food safe when CURED. once they are cured they are food safe. every single one of them."

That is simply *NOT* true.


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## teenagewoodworker (Jan 31, 2008)

well what do you think they put on wood products in stores. you can email the manufacturers and they will tell you that most finishes are safe when cured. they will not dissolve in your body. they will just pass right on through.


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## tbone (Apr 24, 2008)

Betsy, it looks like you got plenty of good advice on the cutting board. But take this as a friendly word of warning: The poisonous brown nuts have NO CHANCE against a Longhorn team that's mad as h-e double hockey sticks that they are not playing Florida for the BCS title.
It's gonna be ugly for the Buckeyes.


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## Brad_Nailor (Jul 26, 2007)

One of the reasons you should use mineral oil to seal a cutting board is that it is NOT a food based oil, and can never spoil. Any oil from a food that can spoil should never be used as a cutting board sealer. And just for the record I don't care what the FDA or the manufacturers say I don't believe that ANY finish is food safe when cured…maybe the ones that SPECIFICALLY say they are food safe…but not ANY


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## teenagewoodworker (Jan 31, 2008)

this might help you decide a bit

http://link.brightcove.com/services/link/bcpid1305031876/bclid1311197674/bctid1358275350

mineral oil doesn't seal.


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## Dusty56 (Apr 20, 2008)

http://link.brightcove.com/services/link/bcpid1305031876/bclid1311197674/bctid1358275350
Charles is so full of information and yet he doesn't understand the concept of having a microphone on his person when he makes videos . The sound quality of his "shows" makes my ears bleed and prevents me from watching them for very long.
I've used Mineral Oil for over 15 years with no issues . It is the least expensive and easiest to locate and apply as needed for my customers . I never apply just one coat of Mineral oil as he did in his video . You can see some of my cutting boards here with Mineral Oil applied . http://lumberjocks.com/projects/8724 
Again , unlike Walnut oil , there are no fears of allergic reactions to Mineral Oil . 
Regarding your bleeding issues , it's all about the Temperature and Humidity . Simply place your hand on a board for a few minutes that you have recently finished and looks "dry" and you will see your hand print where the oil has risen to the surface do to the Temp . change .


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## Brad_Nailor (Jul 26, 2007)

Seal, treat, finish, season….now your just into semantics. I use a commercial butcher block solution that is 95% mineral oil..I apply it liberally to all sides of the board and keep applying it till the board wont soak up anymore.


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## Betsy (Sep 25, 2007)

Never intended to get some many opinions on finishing/treating/sealing a cutting board. We all have our opinions. Experience is the best guide. What works for you you should stick with.

My original question just centered on the why the leakage. I appreciate the chemistry lessons.

As for me and my house - Charles Neil ROCKS!

Thanks all.


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