Denatured alcohol, also called methylated spirits, and mineral spirits are some of the most popular solvents used in woodworking.
While both substances are excellent for various commercial and DIY projects, they cannot be used interchangeably.
Knowing how denatured alcohol vs mineral spirits compare can help you correctly choose one for your next woodworking project.
Which is the better between denatured alcohol and mineral spirits? Well, that depends on your project and specific needs. This write-up provides a detailed look at each solvent, its properties, and its specific uses.
What is Denatured Alcohol?
Denatured alcohol is a clear-colored liquid used for various household, commercial, and woodworking applications. It is also the primary ingredient in shellac—a popular wood finish.
Denatured alcohol comprises ethanol and various chemical additives intended to make it unfit for recreational human consumption.
The added chemicals can include methanol, acetone, isopropyl, castor oil, benzene, gasoline, methyl ethyl ketone, and pyridine.
The alcohol cannot be consumed for recreation purposes due to the induced toxicity, so it is usually exempt from taxation.
Some of the additives, such as methanol, are toxic and can be harmful if ingested. For this reason, denatured alcohol is typically colored purple or blue as a requirement for identification purposes.
Uses at a glance
Properly diluted denatured alcohol is an excellent glass cleaner because it leaves no streaks behind.
In addition, the solvent can remove ink stains from some fabrics and is highly effective against molds and mildew when mixed with water in equal parts.
Denatured alcohol is often used to remove sticky substances like tape residue, glue, and thick layers of grease on meals such as automotive parts.
It does an excellent job at this role due to its quick evaporation time that keeps it from damaging or corroding metal.
Denatured alcohol pros and cons
Using denatured alcohol on wood comes with its pros and cons. Here is a quick look at these strengths and limitations.
Pros of denatured alcohol
- Denatured alcohol is a powerful solvent
- It is inexpensive as its prices do not include taxes
- It possesses antibacterial properties that help remove microbes when using the solvent for cleaning purposes.
- Denatured alcohol is a potent degreaser that works faster than any average detergent or commercial degreaser.
- It dries pretty fast, saving time on any project involving it. The volatility and quick drying time also mean it will not corrode metals.
Cons of denatured alcohol
- Denatured alcohol is toxic for human consumption due to the added chemicals.
- Denatured alcohol is highly flammable and can cause a fire.
What are Mineral Spirits?
Mineral spirits are petroleum-based solvents with numerous applications, including thinning oil-based paint and cleaning paint brushes, paint rollers, and such other items. Here’s how to clean oil paintbrush without paint thinner.
Since they are petroleum-based, mineral spirits are not effective for cleaning acrylic latex or water-based paints. Mineral spirits are excellent thinners that are very similar to commercial paint thinners.
In contrast to paint thinners, mineral spirits are more refined, making them less toxic, with reduced odor and volatile organic compounds.
Some mineral spirits are completely odorless, as their odor-causing components have been removed from the formula. These odorless mineral spirits are commonly used for oil painting.
Uses at a glance
The solvent does not dissolve cured or hardened wood finishes, including polyurethane, lacquer, varnish, and shellac. This property means you can safely use it to clean furniture or any wooden object without damaging the finish.
Some people apply mineral spirits on clear wooden finishes to revitalize or revive the look.
Mineral spirits are your best solution if you have natural or synthetic adhesives on a surface. The solvent will do an excellent job dissolving and wiping off any adhesives, including price tag residue and tree sap on surfaces.
Mineral spirits pros and cons
Like denatured alcohols, mineral spirits have varied uses, which come in handy in any woodworking application.
The pros of mineral spirits
- Mineral spirits are generally less toxic than other similar solvents.
- They are low in volatile organic compounds (VOCs), making them free of strong odors and more comfortable to handle. Mineral spirits are also available in odorless varieties ideal for people with high smell sensitivities.
- Mineral spirits are highly effective in removing paint stains and will remove even stubborn paint spills.
- If you thin paint with mineral spirits, it dries to a smoother and more even finish.
- The solvent is flammable
- Mineral spirits can cause skin irritation.
- Prolonged exposure to mineral spirits can cause brain ailments.
Mineral Spirits vs Denatured Alcohol Side by Side
The best way to decide which solvent is best for your woodworking project is to consider their specific characteristics side by side.
This section looks at the various aspects of both mineral spirits and denatured alcohol that can make either solvent a better fit for your project.
Denatured alcohols have 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.
Mineral solvents are used for all sorts of things. They are often used as paint thinners, but they can also be used for cleaning and degreasing machines.
They are an inexpensive petroleum-based product that can replace the use of vegetable-based turpentine for a fraction of the cost. This is the most common paint thinner for oil-based paints.
Denatured alcohol for cleaning wood
Denatured alcohol is typically used to clean unfinished wood after sanding. It does an excellent job at picking and eliminating the sanding dust without dampening the surface due to its quick-drying property.
Cleaning sanded wood surfaces with denatured alcohol help prep them for finishing or other projects to follow. You want to always use a lint-free cloth when wiping the wood surface with undiluted denatured alcohol to leave no debris behind.
Notice that denatured alcohol is only usable on unfinished wood. The solvent dissolves common wood finishes off the surface, so it will remove an existing finish if used to clean a finished wood surface.
Mineral spirits to clean wood
Mineral spirits do not affect hardened or cured wood finish. This characteristic makes them an excellent cleaning agent for finished wood.
You can use mineral spirits to clean grime, adhesives, and other sticky residues off a finished wood surface. When used on a finished wood surface, mineral spirits tend to restore and revitalize the luster of the wood’s finish.
Consider using a soft cloth when cleaning a stained or finished piece of wood or furniture with mineral spirits. Consider pouring the mineral spirits onto the soft cloth and scrubbing the surface with the saturated cloth for the best results.
Compatibility with water
The constituent liquids used in denatured alcohol are generally miscible with water. These include ethanol, methanol, n-propyl alcohol, t-butyl alcohol, and isopropyl alcohol, making the solvent compatible with water.
This compatibility is the reason you can dilute denatured alcohol by adding water into it for various household purposes and DIY woodworking projects. It is also the reason denatured alcohol works well with water-based finishes.
In contrast, mineral spirits do not mix with water. They are petroleum-based. Oil and water do not mix, and petroleum is an oil. Hence, the spirits are unideal for use in adjusting the viscosity of water-based polyurethanes, varnishes, or paints.
Recommended Reading: Stain vs varnish
Denatured alcohol dries pretty quickly, almost instantaneously. This quick drying is one of the reasons people use the solvent as a preferred cleaning agent when removing adhesives and other sticky substances from metallic surfaces.
The alcohol dries too quickly to corrode the metal. On the other hand, mineral spirits can take several minutes to an hour to evaporate and dry. The more you use, the longer you may have to wait for it to evaporate and dry completely off a surface.
Ideally, the drying times of both types of solvent will depend on the conditions they are used in, but denatured alcohol always dries sooner than mineral spirits.
Nonetheless, experts advise that you do not use drying times as the sole determiner of which solvent to choose between the two. Deciding points should cut across the various factors discussed in this guide.
As already mentioned, denatured alcohol has various toxic elements in its formula. The added chemicals such as methanol make the substance relatively toxic.
The solvent tends to emit nasty fumes that can cause nausea and dizziness, so you want to wear protective gear when handling it.
The toxicity also means you should watch out for spills and never have denatured alcohol in consumable food items.
One main reason for adding the toxic chemicals in denatured alcohol is to make it unfit for human consumption for recreational purposes and make it exempt from tax.
The appropriate personal protective gear to wear when handling denatured alcohol should include protective rubber hand gloves and safety glasses.
On the other hand, mineral spirits are not as toxic, even though ingestion is not recommended. Also, exposure to the spirits may cause minor irritation, so you want to wear the appropriate protective gear when handling them for extended periods.
Despite having no toxic elements added, prolonged exposure to a lot of mineral spirits can cause nausea or drowsiness.
For instance, inhaling the fumes from mineral spirits in a poorly ventilated area for several minutes of hours can affect your coordination.
The relatively benign nature of mineral spirits is due to their heavily refined nature. During production, they undergo thorough refinement to eliminate or reduce sulfur and toxic volatile organic compounds (VOCs).
So mineral spirits are often used as solvents at homes without putting kids and pets at risk.
Both denatured alcohol and mineral spirits are highly flammable substances. You need to use them away from any sources of flame, or they could be a fire hazard.
In the event of disposal, you must follow the recommended safety precautions to dispose of either solvent properly. These precautions apply to any rags soaked with either of the two solvents since improper handling can cause the risk of fire.
Effect on finished wood
When you apply sufficient amounts of denatured alcohol to a finished wood surface for enough time, the solvent can dissolve the finish and remove it completely.
It works on film-forming finishes, including polyurethane, varnish, shellac, and lacquer.
Mineral spirits do not dissolve hardened wood finishes, so you can safely use them on a finished wood without damaging the protective barrier. Instead, the spirits will revive the luster of such film-forming wood finishes.
Denatured alcohol is preferred for use in cleaning glasses mainly because it leaves no residue behind. Instead, it evaporates in its entirety, leaving clean surfaces behind.
This way, surfaces cleaned with denatured alcohol tend to be streak-free and clean. Mineral spirits are petroleum-based and will typically leave an oily residue on the surfaces where you use them.
Therefore, you may have to clean the surface the same way you would any oily residue. A simple way is to use soap and water.
Denatured Alcohol Substitute
A denatured alcohol alternative can come in handy where you are unable to find the solvent for some reason. Thankfully, there are plenty of alternatives you can consider in its place to do the job.
In this case, the main options include:
- Grain alcohol
- Absolute isopropyl alcohol
In any case, the option you select should depend on the intended use scenario and availability. For example, something like absolute isopropyl alcohol may be challenging to find since you need a permit to avail of it.
Substitute for Mineral Spirits
You might be asking yourself “What can I use instead of mineral spirits?
When you cannot find mineral spirits for a particular woodworking application, a mineral spirits substitute can come in handy. Lacquer thinner is a popular mineral spirits alternative, especially for thinning epoxy.
It is equally petroleum-based and leaves an oily residue behind. The alternative here will also depend on the specific use scenario.
Here are some of the common mineral spirits alternatives to choose from:
- Charcoal lighter fluid
- Turpentine (more toxic than mineral or white spirits)
- Nail polish remover
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Is denatured alcohol wood alcohol?
No. Wood alcohol or methanol is one of the chemical substances usually mixed with ethanol to make denatured alcohol. Wood alcohol can be used in place of denatured alcohol as a substitute, but the two are not synonymous.
Is isopropyl alcohol the same as denatured alcohol?
No. Denatured alcohol and isopropyl alcohol are not the same. Isopropyl alcohol is another type of alcohol that shares many of the same uses as denatured alcohol. The latter is ethyl alcohol with various chemical substances added to make it unfit for human consumption.
Is denatured alcohol the same as mineral spirits?
Denatured alcohol and mineral spirits are different organic solvents with different compositions and applications. The main difference between denatured alcohol and mineral spirits is that denatured alcohol appears in violet color while mineral spirits are available as clear liquids.
Mineral Spirits vs Denatured Alcohol Verdict
Choosing between denatured alcohol and mineral spirits mainly depends on your project and its specific needs. Both solvents can be used as cleaning agents and for thinning purposes.
For instance, if you are working with lacquer, you will need denatured alcohol. On the other hand, if you are thinning oil-based paints, mineral spirits are the solvents for the job.
So, consider the nature of the project you need the product for, then choose based on which solvent is suitable for it.