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The Best Oils & Techniques for Finishing Wooden Kitchen Tools

March 12, 2016

Over the past twenty years of working with wood, I have applied many finishes such as soap, shellac, oil, varnish, lacquer, polyester and polyurethane, and urishi. I have poured finishes, mopped them, sprayed, brushed, burnt, rubbed, and polished. I have even experimented with not finishing wood just to see what all the fuss is about. At the very least, it is safe to say that there are many different preferences, techniques, traditions, and recipes out there, from the most basic to the very complicated.

Instead of just suggesting a recipe (which, in the hands of two different "chefs," may result in two very different "dishes"), I wanted to share some guiding concepts about oil finishing woodenware—feel free to skip ahead to what interests you about it most!

Photo by Eberhardt-Smith
  1. Why Finish Wooden Kitchen Tools & Cutting Boards?
  2. Why Oil is the Best Protective Coating
  3. Choosing an Oil for Finishing
  4. Sanding and Wooden Surface Preparation
  5. Applying an Oil Finish

1. Why finish wooden kitchen tools and cutting boards?

Not all wood need be “finished” to be used—but if it requires regular cleaning or comes into close “people” contact, wood greatly benefits from the addition and maintenance of a finish. Wood is, after all, inherently resilient and can last a lifetime or more if properly maintained, gaining both familiarity and grace as it ages.

Specifically, wood in the kitchen is wood at work: Here it is subject to far greater use and more extreme cycles of expansion and contraction that happen with washing, and it's also often in direct contact with the very food that we eat. It's important, therefore, to use discretion in choosing a finish for wooden kitchen items.

2. Why Oil is the Best Protective Coating

There are many different types of wood finishes, but not all of them are suitable for the demands of kitchen items. Varathanes, urethanes, and polyesters are out of the question, in my personal opinion—why would you want to cover a beautiful piece of wood in a layer of plastic, and then eat the plastic when it begins to wear off or you cut through it?

Oil finishes, on the other hand, are great for wood that will be used in the kitchen and needs to stand up to heavy use. Oil will penetrate into the fibers of the wood, where it helps resist absorption—but is also semi-permeable, meaning that it will allow the wood to breathe (much better for the longevity of the wood and the finish as well). It's easy to apply, easy to maintain, and the resulting healthy-looking sheen will only get better looking with age and use. What's even better about oil is that there are several entirely nontoxic, food-safe options to choose from.

Oiling imparts a luminous sheen to wooden surfaces. Photo by Eberhardt-Smith

Oiling wooden kitchenwares is ultimately about cleanliness.

A good cutting board finish should not be thought of as a “bulletproof” coating that renders the surface impregnable, but more like a flexible, workable layer that allows you to scrub it regularly using soap and hot water. This step—keeping things clean—is at the beginning and end of any board finishing process, the basics of which are very simple, with results that are immediately recognizable.

Oil keeps wood moisturized.

Dry wood, not unlike a sponge, is absorbent by nature (think of how a tree moves water and nutrients up from the soil and into branches and leaves, up through the trunk). Wood's purpose in this state is to be saturated with water, seasonally expanding and contracting; it only begins to dry out when the tree dies, or when we start to turn that wood into lumber.

Keeping the surface fibers saturated with oil helps to control wood's natural fluctuation in moisture content, minimizing the likelihood of splitting and cracking while also helping the wood become more resistant to absorption.

Most oils need to be re-applied over time to be fully protective and conditioning. Photo by Eberhardt-Smith

3. Choosing an Oil for Finishing

Not all oils are created alike. Many natural oils, like olive oil and corn oils, can turn rancid after prolonged exposure to air—they're said to "sour" wood utensils and should be avoided. But there are a number of better natural options. At Blackcreek Mercantile, we sell a cutting board oil blend that's specifically formulated to work well on kitchen tools, but here are a few other standard oils to choose from, along with the up- and downsides of each.

Linseed (also known as flax seed) and walnut oils

Widely used in this application for centuries, linseed and walnut are natural oils that can create a very durable wood finish, almost like a natural varnish. Known as "polymerizing oils," they'll somewhat harden the wood fibers as they dry (the chemistry of why this happens is complicated, but the result is pretty straightforward). Additionally:

  • They're most always yellow or amber in cast, a color that is then imparted to the wood that they are used on, and they characteristically oxidize and darken with age and exposure to sunlight.
  • Several coats are necessary to build up enough finish to make a suitably resistant surface—though on the flip side, they're relatively inexpensive, widely available, and re-coating with them becomes progressively easier as the finish begins to build.
  • Even though they're natural products, people with nut allergies may have an adverse allergic reaction to the oils or wood that has been treated with them, so use discretion.
A blended oil that we produce at Blackcreek Mercantile. Photo by Eberhardt-Smith

Mineral oil

Another popular board finish, mineral oil is a 100% neutral petroleum by-product. Highly refined mineral oil is food-safe, used extensively throughout the food industry for anything from machinery lubrication to a baking pan release, and it has an unlimited shelf life (!). While it imparts the same protective and resistant qualities of other oil finishes, mineral oil differs in that it never really dries and it does require maintenance (meaning re-application over time). It's absolutely clear, colorless, and odorless, with a softness (rather than greasiness) to the finish.

Beeswax and wax-based salves

Another popular and food-safe finishing option, salves or “butters” are usually a combination of oils and waxes blended to make application of the wax easier. Wax is a tenacious substance; it also never fully dries and is capable of both covering and resisting most everything. Wax can even be applied over an oil finish, but I observe the rule that once you use wax, there is no going backwards—it's incredibly difficult to remove completely once applied. As a top coat or end treatment, wax is unparalleled as a wood finish, but as a finish in the kitchen, it needs regular maintenance.

4. Sanding and Wooden Surface Preparation

All board surfaces need to be prepped when they're dry, no matter what kind of finish you're applying. Rough, fibrous surfaces—such as your most beloved cutting boards—are difficult to finish, so it's best to address this before oiling. Sanding is an easy, inexpensive way to smooth the surface of wood by removing any scratches with progressively finer scratches. It's important to sand with the grain of the wood, because cross grain scratches are more likely to be visible.

Photo by Eberhardt-Smith

Selecting a sandpaper

Sandpapers are manufactured in grits of graduating coarseness (coarse, medium, fine, and extra-fine)—the lower the number, the coarser the grit. Higher grit papers are available in "wet/dry" or "water-proof" versions, which are usually black and perfect for wet-sanding oil finishes.

  • 35-100 grits are heavy papers reserved for shaping.
  • 150-320 grits are for surface preparation.
  • 400 grit and higher are especially for refining the finish.
Photo by Eberhardt-Smith

Sanding technique

Folding a sandpaper in thirds and just using your hands to scrub the board is an entirely acceptable way of preparing damaged or heavily used wood boards for oiling. (Electric sanders can also be used, but are perhaps overkill unless your board is quite heavily damaged or in need of complete resurfacing—in which case you'll want to purchase extra papers before you begin, as cutting board finishes tend to “gum” and clog sanding papers.)

With cutting board finishing, your goal in surface preparation might not be to completely remove cut marks. Cutting boards are supposed to be cut upon! Often simply re-coating the board with a fresh coat of oil is all that will be necessary.

5. Applying an Oil Finish

"Flooding" the board with oil. Photo by Eberhardt-Smith

Technique

With all oil finishes, the easiest method of application is to begin by flooding the surface, meaning you'll pour a small amount of oil directly on one side. Then—using a clean, lint free, rag—wipe the oil over the entire surface, propping the board up in the sink to let it soak in (don't lay the board flat or place it anywhere that the oil will be a problem).

After the whole board is “wet” with oil, wet sanding may be done to further smooth troublesome grain or rough spots: Using a polymerizing oil, buff the surface clean within 15-20 minutes. The surface should feel dry in the end; let that set overnight. Mineral oil can be left to soak in for hours, even overnight, at which point it should be buffed with a clean rag.

Photo by Eberhardt-Smith

Frequency

For raw wood, plan at least three to five successive coats of a polymerizing oil over as many days, or just two to three coats of mineral oil.

For cutting boards, I generally observe that if a board looks dry, it could be oiled—and on the flip side, a well-oiled board may not need another coat for many months. Re-coating a board to revitalize it can be as simple as flooding the surface, letting it soak in, and buffing it dry. But let’s just say that you really wanted to refinish an old board completely...

"Wet-sanding" for especially ornery grains and rough spots. Photo by Eberhardt-Smith

Complete refinishing

I recently met a woman that goes regularly to estate sales in search of wooden kitchen tools which she collects, refinishes, and puts to use in her own kitchen. This could be a situation in which you might spend some extra time completely reworking and cleaning the piece. Another instance would be if the functionality of the board has been compromised due to deep wear, in which case you could sand away the entire top layer before conditioning it completely. Here's how:

  1. Sand rough spots on a dry board with 220 grit sand paper—if necessary.
  2. Clean the surface with soap and hot water and allow to completely dry.
  3. Flood entire board with suitable oil. Smooth with a 400-grit wet/dry sand paper—if necessary—and allow to soak in.
  4. Wipe away excess, buff with a clean cloth.
  5. Repeat when board shows signs of drying out.
Photo by Eberhardt-Smith

In a pinch, refer to this old woodworking adage: A good oil finish is produced by successive coats. After the first coat, one coat every four days after, then one coat after four weeks, then one coat after four months then every four years after.

If you feel overwhelmed, just remember that wood is a natural, living material. If it feels like you're working too hard, you probably are. Be patient, let the oil soak in. And remember that a little bit goes a long way.

Joshua Vogel is a sculptor, artist, and the author of The Artful Wooden Spoon.

What's your preferred finish for wooden tools? Let us know in the comments!

11 Comments

Stacey S. April 22, 2018
Would this method be applicable to bamboo products? Especially cutting boards?
 
Drew S. September 25, 2017
I recovered my nieces wooden cooking utensils from her flooded home (Harvey/Houston) when we were mucking out the house. Can this nice collection of wooden spoons etc. be sanitized, made mold free and restored to working order again? She loved these utensils and I want to give them back to her as a present. How do I go about this? Or, should I just throw them away as unrecoverable to a healthy state? Thanks
 
Author Comment
Joshua V. March 16, 2016
The board sounds really neat! With a little love, you should be able to put it to use. We have a number of second and third generation pieces that we use regularly in the kitchen. Scrub well with plenty of soap and hot water. After it is completely dry sand smooth with 220 grit or extra fine paper and then begin with the oil. In extreme cases, such as with your furry friends I recommend cleaning the board with a mild bleach solution prior to soap and water, if you think that the board may need disinfecting. This step is fairly common in commercial applications but certainly not necessary as part of your regular maintenance schedule. If your board seems like it has not really been used, perhaps it had never been oiled and a good clean is all it really needs to get you going. Good Luck!
 
Teresa P. March 16, 2016
I found a cutting board, which looks pretty new, in an 40's-50's era metal sink cabinet. Love the sink, it is cast iron. But the metal base is showing rust on the bottom. This was my Grandmother's house and we left the metal cabinet 15 years ago when we moved it. I had seen the cutting board, (which fits in it's own space made for it!) I never thought of using it because it was covered in mice droppings and dead bugs, dirt, etc. I cleaned it up and after we sanded and repainted the cabinet, I slipped it back in it's space and have not really thought about it again. It slides into a space, right under a drawer. So I really never see it. It looks like it's brand new, no knife cuts or anything. Do you think if I sanded it and oiled it, it would be safe to use? Or is this a lost cause?<br />
 
Author Comment
Joshua V. March 14, 2016
Thanks for all the comments.<br />Oil is an easy finish that can be used in a number of applications, including "end grain" butcher blocks. We have a large white oak butcher block that I have been treating with a mineral oil based finish for the past ten, plus years. I am consistently amazed at how well it works as a cutting surface and how easy it is to maintain. Aside from scrubbing it with soap and hot water, all we do is re-oil it when it looks dry, which at this point is about once a season.
 
Joan March 14, 2016
Can this method be used for maple butcher block counters?
 
mizerychik March 14, 2016
Thanks for mentioning nut allergies. I'm a severe tree nut anaphylactic and food prepared on a walnut board soaked in walnut oil would send me straight to the hospital.
 
M March 12, 2016
I'm curious about how oils work with different woods and types of wood cutting boards and surfaces. Which woods are best to get that rich colour and easy-to-maintain sheen?<br /><br />For example, I have an end-grain board that seems to dry out exponentially fast, whether I use oils or an oil/wax mix.
 
Smaug March 12, 2016
"Drying out" isn't really what happens, but you won't be able to build a surface coat on end grain with an oil finish; too much absorption and too much movement. "Sheen" on a cutting board isn't really in the cards if you use it at all. Oil will soak into the wood and solidify, rejecting water and contaminants and, to some extent (very little) strengthening the top layer of wood- to a very small depth; that's really all you'll get from it. There isn't really any issue of compatability of various sorts of woods and oils, though some furniture makers prefer,e.g. Teak oil for finishing Teak.
 
Smaug March 12, 2016
The most difficulty with these finishes is with porous woods- oak is a good example. they don't form a strong enough membrane to bridge the pores, but the real danger- especially if you use the flooding method- is that material will build up in the pores. This then tends to reemerge (it will stay liquid if not exposed to air)-often long after you put the piece to bed- and leave shiny speckles on the surface, which are far harder than one might think to get rid of.
 
Smaug March 12, 2016
I would dispute the advisability of creating a surface coat with polymerizing oils on a cutting board- it won't help any more than a surface finish such as shellac. Two coats is plenty to prep the material, and the second is really only for backup- Really the best way to apply it is to rub it on and keep rubbing until it feels dry, but this is mostly a matter of creating an even finish, not really important on a cutting board. I love wax over oil finishes for furniture, but I don't see any use for it in the kitchen- wax provides very little protection from water or water vapor(unless you actually dip the piece in molten paraffin) and less to abrasion. You need to be really cautious about sanding boards (and counters)- low spots will cause all sorts of problems, from irregularities in the finish to spots where your knife won't cut all the way through. Trees, by the way, do not soak up water like sponges; they use a considerably more complex osmotic process to draw in and distribute water and nutrients. But all in all, a good article.