Minerals. We know we need them in our diet. Minerals are essential for good health. Among the minerals we need are calcium (for bone strength), potassium (for heart health), selenium (for prostate gland health), fluoride (teeth), iron, zinc, copper, and more.
But what about mineral oil? Should we take that like we take fish oil? Or Mineral spirits? Maybe a shot a day might help. Or, maybe not.
What does this have to do with the home shop woodworker? Good question, and one you need to know the answer to for your projects. Each has a place in your shop and a proper time to use them, and sometimes you’ll use each one in the course of the same project. Let’s dig into this, as they sound very similar and may have similar purposes. Or, maybe not.
What is Mineral Oil?
The name mineral oil is actually somewhat imprecise, as it has been applied to a number of different alkanes (organic compounds, and in organic chemistry also referred to as paraffin) over the years.
Mineral oil, colorless and odorless, almost tasteless, is a mixture of higher alkanes from a mineral source like a distillate of petroleum, as distinguished from usually edible vegetable oils. It is insoluble in water, just like wax.
It has many applications, and is used as a wood polish (thus useful in the woodworking shop), a skin moisturizer (good for cracked feet, cradle cap, and treating dandruff), a laxative, and as a lubricant. It’s food safe, and so a good choice for application on that butcher block chopping board you just made for the kitchen.
Mineral oil has a number of suitable substitutes, too, including:
- Beeswax-based board creams
- Coconut oil (solid at room temperature)
Petroleum jelly, also known as petrolatum, and made famous by the Vaseline brand, is a mixture of mineral oils and waxes. Remember when you were a kid with a cold, and your mother rubbed Vicks Vaporub on your chest? It’s a blend of petrolatum (mineral oil and wax) and camphor, eucalyptus and menthol for cough suppression and as a topical analgesic.
Now, all of those uses have little or no application in the woodworking shop, unless you have a cold. But this shows the versatility of mineral oil. As a food-safe product, it fits in with your kitchen projects nicely as a finish on woods that will come in contact with foods like chopping blocks, serving platters, salad bowls, countertops, and such.
Mineral oil is relatively stable and doesn’t spoil when exposed to heat. On woods, it applies clear, making it a good choice when you want the natural grains to show through and look natural. It is an excellent wood preservative and will protect furniture equally well as furniture polishes will. It can even be taken orally (a laxative).
What Are Mineral Spirits?
Mineral spirits, or sometimes referred to as white spirits, is also petroleum-derived, but its uses are far different from those of mineral spirits.
Mineral spirits are also known as mineral turpentine, and petroleum spirits. It is a clear liquid used as an organic solvent in painting. It is 100% petroleum distillates and has no additives. It is also a less-expensive petroleum-based alternative for vegetable-based turpentine.
After distillation, mineral spirits are also heavily refined to remove or reduce volatile organic compounds (VOC) and sulfur. You don’t want the smell of rotten eggs lingering in your shop or on your paint brush or hands. VOCs are emitted as gasses from the distillate, and examples of VOCs include benzene, formaldehyde, toluene, and ethylene glycol.
Its primary use is for thinning oil-based paints. However, it can also be used to thin or clean stains and varnishes. You’ve likely used it before in your shop after a painting job, or to clean your brushes and hands.
There are substitutes for using mineral spirits, and some of them you might have used:
- Denatured alcohol: the most noticeable difference with mineral spirits is that it appears as a purple liquid while mineral spirits tend to be clear;
- Acetone: think nail polish remover. They are actually quite different, even though both are used as a paint thinner. Acetone is more commonly used to thin lacquers; and,
If you barbecue and use a charcoal lighter fluid, you know this can serve as a substitute, too. It’s actually a rebranded mineral spirits to identify its specific use.
Used as a solvent, mineral spirits can be applied to woods to cut through grime and build-ups from polish, wax, and oils. It’s actually a common practice to clean woods with mineral spirits before adding a stain or paint. Sand the surface smooth, soak a clean cloth in the spirits, wipe down the dusty surface, and you will be ready for staining or painting.
Although used for the same purpose to thin paints, mineral spirits and turpentine are not the same. Turpentine comes from pine tree distillation, while mineral spirits are a petroleum distillate.
Mineral spirits are not food safe and should not be used anywhere near food. However, if you have decided to refinish your chopping board, you can use mineral spirits to clean the board and remove any kitchen grime before you apply mineral oil as your new finish.
What Are The Differences Between Mineral Oil and Mineral Spirits?
Now that we know what the two of them are, it’s pretty easy to tell the differences. While both of them are petroleum-related, and both have the word “mineral” in the name, the commonality pretty much stops there.
- Both are clear and colorless, but while mineral oil is odorless, you all know the smell of mineral spirits, also called mineral turpentine (as distinguished from plant-based turpentine). However, if you are willing to pay extra, you can purchase an odor-free mineral spirits ($10 per gallon vs $15 per gallon for the odor-free).
- Mineral oil is food safe, while mineral spirits are definitely not. While mineral spirits might have a place in the refinishing of a cutting board, it is only to clean it and prepare it for a new finish, which could be mineral oil.
- While each of them is technically flammable, mineral oil is much less so. Its flash point is around 234 degrees Fahrenheit, and as such can’t be called explosive; mineral spirits has a flash point just over 100 degrees Fahrenheit, and is flammable when exposed to an open flame or sparks.
- Mineral oil will not thin oil-based paints or clean your paint brush; mineral spirits does both.
- Mineral oil can be ingested, or when mixed with wax be applied to your skin; mineral spirits should never be ingested, although it can be used to clean your hands of stain or paint without harming you. And, after doing so, you can use a skin moisturizer made with mineral oil to treat your hands.
- Mineral oil with wax and additives that becomes Vicks Vaporub can help treat a cold; mineral spirits has no such quality.
- Both have a part to play in furniture restoration – mineral spirits to help strip the furniture of its old finish, polish and wax buildup, and grime; mineral oil as the finish once the old one has been removed.
The nature of this article and its subject matter did not lend itself to the use of videos to enhance the message or the answer to the main question. So, we have none to recommend to you today. The answer, though, is clear enough that video demonstrations really aren’t necessary.
Different, not interchangeable, but each can play a part in some woodworking projects. The differences are stark, and you don’t want to confuse one for the other. However, each has a place in your woodworking shop, and you should keep some of both handy for when you need to use their strengths.