Butcher block countertops - stain and finishing

In short: People online tend to go to extremes and think there's only one way to do things. You're fine.

Technically, your countertops are not food safe. The solution is simple, don't eat off of them, don't use them as a cutting board. If food hits it, it isn't magically going to go nuclear. If you slapped a steak on your countertops, handed me a knife and fork, and told me to have at it I would do so.
You would need to regularly and irresponsibly eat off of the countertops for there to be any actual chance of a negative outcome.

The most recent issue of The American Peasant newsletter happened to present the relative merits of various finishes for a handmade dining table. Christopher Schwartz has been a fine woodworker for a very long time, and his advice was as follows:

A Finish for the Top of a Dining Table

Almost every week on the Open Wire, we get asked some variation of the question: What finish should I use for the top of a dining table?

My answer is not going to be the most obvious one (polyurethane/varnish) or the most durable (conversion varnish or – shudder – bartop). Instead, my preferred finish comes from the fact that these three qualities are now most important to me:

1. I want a finish that is easily repaired, even if that means it is less durable.

2. I want a finish that looks better the more it is used.

3. I want a finish without dangerous solvents or heavy-metal driers.

So why do I no longer like the highly durable finishes, such as conversion varnish, lacquer and polyurethane/varnish? They all have poisonous solvents, which the woodworker (me) has to endure. The finishes are safe (enough) after they have cured. Also, these finishes look great until they reach a tipping point, but then they deteriorate and look terrible. And they are difficult to repair. Usually you have to strip the finish and start over.

What about shellac? It is easy to repair and doesn’t have to use a dangerous solvent. Correct. Shellac is OK for tabletops. It is easy to repair. Usually you just have to pad on some more shellac. But when it deteriorates, it looks like crap – just like lacquer and polyurethane/varnish.

If I want a shiny, high-style finish, then I will definitely use shellac. And a good coat of wax.

So what meets all the criteria? Several finishes.

1. Paint. Don’t immediately discount it. Paint is durable, can be non-toxic, looks better when it gets beat up. It is easy to repair (add more paint). Most woodworkers are horrified at the idea of painting a tabletop. I am not.

2. Some sort of oil, wax or combination of oil and wax. These finishes are so safe they can be edible. Beeswax and raw linseed oil are used to coat our foods – or even used as food. They are not durable at all. But they are easy to repair (add more oil and/or wax). And they look better the more they are used. (My daughter Katherine – yes, the same one who used to vault herself off our trestle table’s breadboard ends) makes and sells Soft Wax 2.0 here. We let readers know on our Lost Art Press blog when new batches are available.)

3. Soap. It is completely safe. Easy to renew/repair. But it offers almost no protection. It is used in many Scandinavian countries on furniture, woodwork and floors. My desk has a soap finish and I can attest to the fact that it looks better with age. After almost 10 years it has a glow that no finish can give you on the first day.

I don’t expect you to follow my advice. It takes time to realize that all these fancy film finishes are really short-term solutions. If your spouse really wants a durable finish on a tabletop, here’s what I would do:

Mix any oil-based polyurethane/varnish 50/50 with low-odor mineral spirits. Wipe on a thin coat. Wipe it until it is just barely there. Let it dry. Scuff-sand it a little with #320-grit sandpaper until it is smooth. Then add another very thin coat of the mixture. Repeat five or six times until the finish starts to build. It is time-consuming. When it fails it will look like crap. But it will protect the tabletop for a good long while. (Perhaps until you come to your senses and switch to an easily repaired finish.)

If you visit the site and look at the dining table photograph, the refinished table top is absolutely gorgeous, with the subtle glow and beautifully revealed grain of a wax finish. As the article suggests, you're making a trade-off between short-run labor savings in a low-maintenance finish that will require extensive work to strip and refinish, versus a finish that requires regular maintenance.

Aside from the solvent exposure while applying them, polymer finishes aren't especially toxic once cured. Unless you're actually carving on the counter, they're not going to be a significant source of microplastics, and it's easier to sanitize a fully sealed surface. However, one thing I've noticed about wood finishes in wet environments - you can get dark mold growth in the wood under a urethane layer, and the stain is nearly irremediable, millimeters deep. This doesn't tend to happen as much with butcher block mineral oil, because the end grains can still dissipate moisture.