The Literary Workshop Blog

Although I don’t make a lot of spoons these days, I still haunt the spoon-making discussion groups on social media, and this is one of the most common questions I hear. How can you be sure that the wood finish you’re about to use is actually food-safe?

Here are some freshly-finished utensils made from eastern red cedar. Dust from this wood is a known irritant, and the oil finish hasn’t been officially certified as food-safe! Will they poison everyone who cooks with them?!? No, they won’t.

Let’s say you’ve made a cutting board or a wooden spoon, or maybe you’ve built a baby crib, and you want to be extra-sure that the finish won’t poison somebody.

You go down to the home center and start looking at wood finishes, and only a few (mostly expensive oil-based finishes) make any claims to be safe for food contact. What about the rest of them? Can you safely finish that cutting board with Danish oil? If the baby if starts chewing on the crib rails, will a lacquer finish send her into anaphylactic shock? Why on earth don’t companies tell you if their product is or isn’t toxic when cured?

Or maybe, just maybe, we don’t get the answers we want because we’re not asking the right question.

In a classic article, finishing expert Bob Flexner points out that no government agency actually certifies any wood finish as “food-safe.” A company can call its finishing product “food-safe” at its own risk, but that claim has not been verified by anybody.

So does that mean that there’s no safe wood finish on the shelves today? That only raw, unfinished wood is truly food-safe?

Not at all. Here’s what Bob Flexner has to say:

…there is no evidence of any common wood finish being unsafe for food or mouth contact once it has fully cured, so a distinction between food-safe and non-food-safe is speculative.

You can’t be absolutely sure about the food safeness of any finish you put on wood. There could even be problems with mineral oil and walnut oil that we just don’t know of yet. There could also be problems with raw linseed oil, pure tung oil, wax, shellac and salad bowl finish, because we don’t know where these substances have been or what they might have come in contact with. None has met the regulations laid out by the FDA.

But, based on FDA regulations, the way finishes are made, the complete lack of any evidence to the contrary, and the countless other untested objects food and children come in contact with, there’s no reasonable argument for avoiding the use of any finishes.

(The whole article is worth reading in full, though it’s only available on web archive sites now.)

In other words, the question we should be asking ourselves is this: “Which wood finishes are known to be toxic when cured?”

And the answer, at least in the USA, is “none of them.”

According to Bob Flexner, there are some specialized commercial finishes in some industries that come with health hazard warnings, but they aren’t the kinds of products you can find on the shelves at your local home center.

When you think about it, we come into contact with various cured wood finishes pretty frequently–on wooden floors, wooden furniture, wooden paneling, wooden handles, you name it. Have you ever heard of anybody reacting negatively to handling finished wood? I haven’t. Our common experience indicates that, as far as anybody knows, none of the the wood finishes you can usually buy off the shelf at a home center in the USA are toxic when fully cured. (Check the label. Is there a warning that the finish contains heavy metals, like lead or mercury? No? Then you should be good to go.)

That’s not to say that applying finishes is non-toxic. Many common finishes, like lacquer, give off pretty noxious gasses as you apply them. Others, like boiled linseed oil, can cause fires if oil-soaked rags are improperly stored. So you should always take reasonable safety precautions when applying a wood finish. But once the finish has cured, the finished wood is as safe to handle as any other common object in your everyday environment.

There are even a few wood finishing products that are edible: shellac, beeswax, mineral oil, and vegetable oils (e.g. flaxseed oil, hemp oil, and walnut oil). Some purists stick to these products in older to be double-extra, super-safe. I have also known people to just use whatever vegetable oil they have available, like olive oil or sunflower oil, but that’s a mistake because those vegetable oils don’t actually dry. If it doesn’t wash right off of the utensil, it will eventually go rancid. So if you absolutely must use an edible finish, stick with an oil that dries: flaxeed/linseed, hemp, or walnut oil.

For my own wooden spoons and spatulas, however, I use a three-part blend of polyurethane, mineral spirits, and raw linseed (flaxseed) oil. The oil and polyurethane mix and dry in the wood, and the mineral spirits (added only to thin the mixture so it soaks into the wood) evaporate completely.  The finish is extremely easy to apply, and once it’s cured, it stands up to repeated washings in the kitchen. And it has never, ever poisoned anybody who used a utensil that was finished with it.

So yes, it’s fine to finish your cutting board with the boiled linseed oil from your local home center. Just let it dry completely before you start chopping fresh veggies on it. And yes, go ahead and use lacquer or polyurethane on that baby crib.

Unless it’s the mother’s first baby, and she’s a health nut.

In which case, give that crib a coat of food-grade flaxseed oil followed by several coats of shellac topped by a hand-rubbed coat of beeswax. Tell the anxious mother that while the finish won’t exactly be tasty, it is certifiably edible.

 

 

Author Note: I drafted this post several years ago but am just now getting around to publishing it. Although I don’t make a lot of spoons anymore, I still want to share this handy technique that I’ve used over the years to fix little voids, not only in spoons but also in furniture.

If you have ever found yourself carving a spoon, and you’ve gotten down to making the final, finishing cuts only to realize that there are a couple bug holes or a bit of tear-out that’s just too deep to carve past, you know that sinking feeling that you’ll just have to toss this almost-finished utensil in the burn pile and start over. 

Or will you? 

Not all flaws are fixable, but there is a way to safely and effectively fill in some small flaws and save that nearly-finished spoon from the burn-pile. It’s a common trick that I picked up from a wood turner. 

All you need is bit of very fine-grained fill material and regular CA glue (superglue). Here’s how it works: 

First, find a good fill material. You have lots of options, and some of them are probably lying around your shop already. If you want a relatively invisible fill, try using sawdust from the species you’re working. Use a fine-toothed saw or even coarse sandpaper to produce the dust. The finer the better. You can also use organic substances, such as fine coffee grounds. I have also successfully used crushed stone–you can get many different kinds on the internet. Again, get the finest grains available. I especially enjoy using brightly colored materials that turn the flaw into a decorative feature. Just be careful, as some powdered materials (like metals) can be hazardous to work with. 

Second, use the right bonding agent. It’s just regular superglue. The thinner the better–not the gel kind.

Now for the technique. For a fairly shallow void or crack, fill it with the fill material, and mound the material up over it just a little. Flood the whole area with superglue. Let it dry completely. You can speed it up with heat from a hairdryer or heat gun. Then scrape or sand it level. You can put your finish right over it, though you should be aware that the superglue can affect how some finishes penetrate, so don’t over-saturate the surface with the superglue. You need just enough to saturate the fill material completely.

For projects with a lot of holes to fill, as on the tabletop above, I made myself a little fill-kit. The bag of sawdust is for filling in the bottom of deep holes so I don’t have to use as much of the nicer, expensive fill except at the very top. The green powder is crushed malachite stone. (Again, exercise caution in use, as it can be toxic in its powdered state.) The baby spoon is for putting the fill in precisely the right place, and the old toothbrush is for moving it around and making sure every corner of each gap is filled in before applying the superglue.

For deep voids, you may need to use a couple layers of fill. For little cracks, use the point of a knife to spread the crack a bit to allow more of the fill to enter. Then apply the superglue. With a bit of practice, you’ll figure out what works in different situations. If you need to fill a crack or void that runs into an edge, use masking tape to shore up the fill while it dries.

Once the superglue is hard and dry, I scrape the fill level with a card scraper. You can also sand it level, but it will take a lot longer. The whole process takes just a couple minutes. It really is that easy.

But how well do these fills hold up in everyday use?

I’ve stress-tested them in my own kitchen, and I’ve found they are very durable, even on the business end of a spoon or spatula.

These glues are typically good up to about 230F, and since boiling water doesn’t get any hotter than 212F, you’re not likely to soften the glues in any kind of water-based dish. (If you’re plunging wooden spoons into boiling oil, which can get a lot hotter than water… well, please stop. You’re going to catch something on fire.)

If you really need a glue that will outlast the wood, there’s always the original JB Weld, which is good up to about 500F. The only drawback is the ugly gray color, but you can tint it with lampblack. Use a bit of soot scraped off any smooth surface that’s been near an open flame. You can use a candle flame to blacken the blade of an old butter knife if you like. Mix the soot into the epoxy, and it should turn nice and black. 

I need to emphasize that there are limits to the size/type of flaws that you can fix using this technique. It’s best for filling in small gaps–little cracks or shallow voids that would otherwise get bits of food stuck in them. It’s ideal for filling in a bug hole or two, or for filling a wide but shallow gap. But it won’t increase the structural integrity of the utensil, so make sure the utensil is good and sturdy without the fill. I don’t think I would use this technique to try to fix end-checking in the bowl of a spoon, which is the most common kind of flaw you’ll see in a wooden spoon. Not all flaws are worth trying to fix. 

But once you start using this technique on wooden spoons, I think you’ll find it very effective. And you might find it useful on other woodworking projects, too. 

Who doesn’t love a nice ribbon bookmark? Older bibliophiles will remember when many fine hardcover editions of literary classics came with a ribbon bookmark. I always loved them, though I’m afraid they aren’t as common as they used to be.

Fortunately, even if your favorite hardcover or leather-bound book doesn’t come with a ribbon bookmark–or if it doesn’t come with enough ribbons–it’s very easy to make your own ribbon bookmarks.

I learned how from a guy named Justin, who was a student of mine. A few years ago, we were both part of a theological discussion group at our university, and one day somebody noticed that Justin’s Bible had probably half a dozen ribbon bookmarks, all different colors. We were a little envious and wondered where he had gotten a Bible with so many ribbon bookmarks. He smiled and showed us how he had made them himself out of some very simple materials.

First I’ll show you how you can add the ribbon bookmark(s) to your book, and then I’ll show you how to make them.

Pretty much every book that’s not a paperback has this handy little gap at the spine. You’re going to attach your ribbons to something long and thin that you can slip into this gap.

Here’s how you do it.

First, make the slip.Use stiff poster board or a sheet of vinyl, just something thin you can punch a few holes in. You can even use a cereal box or something like that. Cut it into a long slip that will fit nicely into the book’s spine. The exact dimensions aren’t important, but if you make it about half as long as the book is tall, you can adjust the length of your bookmarks by moving it up and down inside the spine.

Now get some ribbon. I recommend the 1/4″ wide ribbon that you can get at any fabric store. You can get the wider 3/8″ size if you prefer. Be sure to choose a color and texture that you really like. I prefer plain, smooth polyester ribbon, which is soft and flexible and feels nice in the hand. Other kinds of ribbon are quite stiff or have a lot of texture, which is not ideal for a bookmark. Ribbon is not expensive, so you can get several different colors if you like.

You can attach the ribbon to your slip in many different ways. I decided to punch holes, fold the ribbon through the hole, and superglue it to itself. (I pressed it between a couple pieces of waxed paper while it dried.) You could also put the ribbon through the hole and staple the ribbon to itself. Or you could just tie it off in a little knot, which is how my student had attached his. Just make sure the ribbon can’t pull free if you tug on it a little bit.

With the ribbons attached, cut them to the proper length.

Just make sure you leave enough on either end to drop down into the spine and stick out from the pages.

I was making several of these for Christmas presents, so I put down some tape on my table to help me cut every ribbon to the same length. You may want to customize the ribbon’s length to your book’s size. And you can always leave it a bit long at first and trim it to final length once you’ve installed it in the book.

Don’t forget the singe the ends of the ribbons with a flame so they don’t ravel.

Now slip your new bookmark into the book’s spine, and you’re done!

After just a few minutes’ work, you have made a fine ribbon bookmark to mark your place in your favorite book.

But since these are so quick to make, it would be a shame to make just one. Why not make a few for your other favorite hardcover books. You could even make some as gifts for your bookish friends!

Or maybe it’s time to sit down in front of the fireplace and enjoy your favorite book, enhanced with a ribbon bookmark you made yourself.

Lectio felix! (Happy reading!)