As an Amazon Associate we earn from qualifying purchases.
In this article, learn everything you need to know about mineral spirits and denatured alcohol. After giving you the rundown on these two solvents, I’ll delve into their similarities, differences, and applications. Keep reading to find out which is better.
Contents
What Are Mineral Spirits?
Mineral spirits are a petroleum-based solvent. Solvents are substances that have the power to dissolve other substances. Mineral spirit is a solvent for oil-based paint, which makes it useful for cleaning brushes, rollers, and even paint trays. It is not effective for cleaning water-based or acrylic paint.
Mineral spirits are very similar in composition to paint thinners, but have been more refined. The refining process reduces odor, limits the toxicity, and decreases the amount of volatile organic compounds (VOCs) released by the substance.
Mineral spirits also dissolve automotive grease, making them an effective cleaner when stripping or replacing parts. After wiping up excess spirits and allowing the metal to dry, it is clean and ready to be relubricated.
Mineral spirits will not dissolve hardened or cured wood finishes, such as polyurethane, varnish, lacquer, or shellac. It can be used to clean wooden objects and furniture without damaging the finish. In fact, an application of mineral spirits can be used to revive or revitalize clear wood finish.
Mineral spirits are effective at dissolving both natural and synthetic adhesives. The residue from price tags will quickly wipe off with an application of mineral spirits. Garden tools that have become logged with sap can be soaked in mineral spirits to remove the sap and improve their performance.
Mineral spirits evaporate within 15 or 20 minutes, leaving behind no residue. For this reason, it is often used to prepare surfaces such as wood or metal to accept a finishing product or adhesive.
What Is Denatured Alcohol?
Denatured alcohol is a clear, watery liquid used as a solvent, degreaser, and wood finish remover. It is also one of the primary ingredients in a popular wood finish, shellac.
Denatured alcohol is composed of ethanol and various additives. The purpose of the additives is to make the ethanol unfit for human consumption. Methanol is the most common ingredient used to denature alcohol, other substances used include isopropyl alcohol, acetone, castor oil, gasoline, benzene, and pyridine.
Read my comparison on denatured alcohol and acetone.
These additives make the alcohol unfit for human consumption. Methanol is particularly toxic, and can cause blindness or even death if ingested. Denatured alcohol is often required to be sold with coloring added, usually blue or purple, to make the dangers clear.
Since the alcohol cannot be used for recreation, it is not taxed or regulated like pure ethanol or commercial alcoholic beverages. Thus, you can purchase denatured alcohol without needing to show an ID.
Denatured Alcohol Uses
Denatured alcohol has many applications. It can be used as a solvent, cleaning agent, fuel additive, or even an extermination aid. It is highly flammable, and should be kept away from sources of ignition.
Appropriate personal protective equipment for handling denatured alcohol includes safety glasses and chemically resistant gloves. The fumes can cause dizziness and nausea.
When properly diluted, denatured alcohol is an excellent streak-free glass cleaner. Denatured alcohol can remove ink stains from certain fabrics. When mixed with equal parts water, spraying denatured alcohol on mold and mildew will help remove it.
Denatured alcohol is often called into service to combat stickiness. From glue and tape residue to thick layers of grease on automotive parts, denatured alcohol can handle it all. Best of all, it’s quick evaporation time means that it won’t damage or corrode metal.
In woodworking, denatured alcohol is applied to freshly sanded wood with a clean cloth to clean and prepare the wood for finishing. Denatured alcohol dissolves the common wood finish, shellac. It can be used to remove or revive an old shellac coating, to correct mistakes while applying new shellac, or to thin shellac before application.
Plants infested with mealybugs or red spider mites can be sprayed and wiped with diluted denatured alcohol to cure the infestation.
Another name for denatured alcohol is ‘methylated spirits.’
Mineral Spirits vs Denatured Alcohol
These two common solvents have much in common, but their differences are equally important.
Similarities
Both substances are highly flammable. They are used for similar purposes and require the same safety precautions. Either will remove ink from fabric.
Flammability
Both mineral spirits and denatured alcohol are highly flammable substances. When working with either, care must be taken to avoid potential sources of ignition. There is a particular fire risk associate with solvent-soaked rags. Proper safety precautions include storing rags in a closed container and allowing the solvent to fully evaporate outdoors.
Solvency
Mineral spirits and denatured alcohol are both highly effective at cutting through greases, oils, and adhesives.
Ink Removal
Both mineral spirits and denatured alcohol can be used to remove ink stains from clothing or fabric. Always test the fabric in an inconspicuous place before attempting to clean a highly visible stain. These solvents remove ink by dissolving it, but they can also dissolve other fabric dyes in the process.
Safety
Neither mineral spirits nor denatured alcohol could be described as gentle. Keeping a well-ventilated workspace and avoiding sparks and flames is essential to safe usage of either solvent. Chemical resistant gloves and safety glasses are required protective equipment for working with these substances.
Differences
While their applications may be similar, the formulation, toxicity, and even color of denatured alcohol is different from that of mineral spirits.
Color
Both denatured alcohol and mineral spirits are naturally clear, colorless liquids. Governments and regulating agencies often mandate that denatured alcohol be colored blue or purple, to prevent it from being mistaken for consumable or recreational alcohol.
Contents
Mineral spirits are petroleum based. Denatured alcohol is ethanol based.
Toxicity
Denatured alcohol is formulated with the goal of being toxic if ingested. The chemicals added, such as methanol, are highly dangerous to human health. While exposure to mineral spirits may cause irritation and ingestion is not recommended, mineral spirits are less toxic than denatured alcohol.
Effect On Finished Wood
Denatured alcohol, applied in sufficient quantities and given enough time, can be used to completely dissolve and remove film-forming finishes such as varnish, polyurethane, lacquer, and shellac.
It is useful to revive shellac, but should not be applied to other finishes due to the risk of damaging the protective barrier. Mineral spirits are gentle enough to revive clear film-forming wood finishes without removing them.
Major Distinguishing Factor
Mineral spirits are petroleum-based. Petroleum, an oil, does not mix well with water. Therefore, mineral spirits cannot be used to adjust the viscosity of water-based varnishes, polyurethanes, or paints.
Denatured alcohol works well with water based finishes. It can also be diluted with water for a variety of household purposes such as removing pests from plants or cleaning mirrors.
When to Use Mineral Spirits
Choose mineral spirits when you need a gentle, nontoxic solvent to remove adhesive from finished wood.
Mineral spirits are useful when working with oil-based paint. They can be used to clean and prepare a surface for painting, to thin paint before application, and to remove paint drips and splotches.
Periodic application of mineral spirits to finished wood helps revive and revitalize the finish.
When to Use Denatured Alcohol
Choose denatured alcohol to clean and degrease metal.
While not as effective or quick as paint thinner or varnish thinner, denatured alcohol will eventually dissolve clear, film-forming wood finishes.
Use denatured alcohol to thin, correct, refresh, or remove shellac.
Which Is Better, Denatured Alcohol or Mineral Spirits?
These two substances have a lot in common and can even be used interchangeably in certain situations. Either can be used to remove sticky residue, glues, and adhesives. Both are effective at preparing wood surfaces for finishing.
However, denatured alcohol is the more versatile and useful of the two solvents. Not only can it be used to dissolve a wood finish, it also cleans glass, kills certain bugs, and can even be used as a fuel for camping stoves.
