What are mineral spirits?

You could be reading some DIY instructions and see something that calls for mineral spirits, or white spirit if the instructions originated in the UK. But what are mineral spirits? Let’s dig in.

Mineral spirits are a solvent sold in hardware and paint stores. They are a petroleum distillate, useful as a paint thinner, and also for thinning or removing grease and oil. In the UK it’s called white spirit, and in Australia and New Zealand, it’s called mineral turpentine.

Origin of mineral spirits

What are mineral spirits
Although they have many other uses, you’ll find mineral spirits in the paint supply aisle of retail stores, with other types of paint thinner. This is type II, the odorless variety.

Mineral spirits were originally invented in 1924 by W.J. Stoddard as a dry cleaning solvent. They evaporate quickly and dissolve oils, making them very effective for cleaning clothes that can’t handle soap and water. Stoddard solvent, as it was then known, quickly became the most common solvent used in the dry cleaning industry. However, Stoddard solvent also catches fire very readily. It was safer than gasoline, which it displaced, but still not safe enough to satisfy the insurance industry. By the late 1950s or early 1960s, other non-flammable solvents displaced it.

But this particular solvent has plenty of other uses, as it turns out. The obsolete chemical for dry cleaning went on to have an even longer career as both a household and an industrial product. You’ve probably never heard anyone call it Stoddard solvent, but it’s the same thing.

In the United States, we call it mineral spirits. Use of the word mineral in the name distinguishes it from competing solvents such as turpentine that are derived from plants. In the UK it’s called white spirit, while in Australia and New Zealand, it’s called mineral turpentine. In spite of the use of the word “white” in its UK name, it is a clear liquid.

Types of mineral spirits and where to buy them

There are three types of mineral spirits, which differ mostly in the way they are produced. For household use, type II, the odorless variety, are the most useful, as they have much less in the way of harmful fumes. The variety you’ll most frequently find in stores is type II. But in specific industrial uses, types I and III can be more useful. For example, asphalt contains type I.

You can buy them in stores that sell paint. Typically you will find them in the paint section of hardware stores and home improvement centers, sold by the quart or the gallon. A gallon can costs about $13 in 2020.

Mineral spirits are much safer than most of the other solvents sold alongside them, such as MEK. They are less likely to damage the surfaces you use them on, and less likely to damage you as well. However, painters can develop a brain ailment due to long term exposure to it, even the safer type II odorless variety. Use a respirator if you use them every day. For hobby use, it’s best to use them in a well ventilated area, and when possible, consider using alcohol to clean instead.

Also, wear gloves when using mineral spirits. It can cause chemical burns on your hands. Rubber gloves protect you from that.

Household uses

Perhaps the most common potential household use is for removing adhesives. It’s very good for removing stickers, price tags, tape, and the like from a variety of surfaces. There are several other solvents that will do this, but the cost per ounce for mineral spirits may be lower, and it also has other uses.

Mineral spirits are a good thinner for oil-based paint, and I use it to clean oil-based paint off paintbrushes. It’s less toxic than turpentine. I prefer to use latex paint. But when I need to use an oil-based paint, I make sure I have some on hand for cleanup.

When I installed a peel and stick backsplash over my old laminate, I prepared the surface by wiping it down with mineral spirits. It was amazing how much gunk came off, and the adhesive stuck very readily to the freshly cleaned surface.

In woodworking, mineral spirits are very useful. After stripping old finish off a piece of furniture, you can use it on #0000 steel wool to remove the stripper. Then, after sanding and repairing the piece, you can apply some of it to the bare wood to see what the wood will look like when finished. Once it evaporates, you can either fix the flaws you found, or, finding none, finish the piece. You can also wipe down wood with a rag dipped in mineral spirits after sanding to remove any fine particles that remain.

I sometimes use mineral spirits when repairing or restoring vintage toy trains or electric motors. It readily dissolves old gummy lubricants, allowing me to re-lube with fresh, modern synthetic products to make them run better than new. In any mechanical application where you’re dealing with old lubricants, mineral spirits are very useful.

Mineral spirits also make a good contact cleaner. I sometimes clean the contacts on circuit boards with them, or the entire board, if the board looks ratty.

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