If you buy something through a link in our posts, we may get a small share of the sale.
In this article, we compare and contrast two popular solvents; acetone, and denatured alcohol. After revealing their properties, we’ll explain when to use acetone, and when denatured alcohol is a better choice. Along with revealing the major differentiating factor, we’ll tell you which is better and why.
- What Is Acetone?
- What Is Denatured Alcohol?
- Acetone vs Denatured Alcohol
- Major Differentiating Factor
- When to Use Acetone
- When to Use Denatured Alcohol
- Which Is Better, Acetone or Denatured Alcohol?
What Is Acetone?
Acetone is a colorless, liquid solvent. It is commonly used to produce petroleum products, including plastic. On its own, it is used as a cleaner, solvent, degreaser, and thinner.
Acetone’s most popular household use is in nail polish remover. Around the house, acetone can be used to remove scuff marks from floors or unstick super glue from wood, though it needs to be wiped away with water after doing it’s job to avoid damaging the surface.
When porcelain tubs, sinks, or even coffee cups become stained, acetone mixed with water is an extremely effective cleansing agent.
Acetone is highly effective as a degreaser. It is used to remove the oils present in wool, to make the fiber suitable for use in the textile industry. It is also commonly used to strip silk gum from silk fibers, making them shinier and smoother.
Although it is non-toxic enough for limited external use (extended contact with acetone can cause dermatitis), acetone has more powerful applications for woodworking as well.
Acetone is used to change the viscosity of lacquer, especially lacquer used in the automotive industry. Due to its fast evaporation rate, acetone helps keep automotive lacquer from dripping or streaking while it dries.
For other lacquer applications, pure acetone sometimes makes the finish dry too fast. In this case, it can be combined with other solvents to slow the dry time. Lacquer thinners are made from a combination of acetone and one or more other solvents, such as amyl acetate, ethyl acetate, keotone, or toluene.
Acetone has low chronic and acute toxicity. This means that short-term or long-term exposure to acetone is unlikely to cause a harmful immune response. In fact, acetone is naturally produced by the human body as a byproduct of breaking down fat.
However, acetone is mildly irritating to the skin, nose, and throat, and should not be ingested. Using acetone in a well-ventilated environment helps reduce the risk of unpleasant side effects from inhaling acetone fumes.
Plastics produced with acetone or acetone-like substances can be damaged, smeared, or even dissolved by acetone. Polystyrene and PVC are two such plastics. Where melted plastic has adhered to another surface, rubbing the affected area with acetone can be an effective method of removal.
What Is Denatured Alcohol?
Denatured alcohol is a liquid solvent, degreaser, and sanitizer used in woodworking, automotive and manufacturing industries, and in the home.
To make denatured alcohol, an additive is mixed in with ethanol. The most common additive is 5-10% methanol, a highly toxic liquid. For this reason denatured alcohol is sometimes referred to as ‘methylated spirits’.
Whatever additive is chosen by the manufacturer, the result is the same: making the alcohol unfit for human consumption. All denatured alcohols are toxic if ingested. Most have a strong unpleasant aroma and a bad taste. Blue or purple coloring is commonly used (and sometimes mandated) to advertise the undrinkability of this useful liquid.
Denatured alcohol can be used in its pure form or diluted with water.
Denatured Alcohol Uses
Pure denatured alcohol is often used in woodworking, especially when working with shellac. Shellac is formulated from resin and denatured alcohol. The amount of denatured alcohol added to the resin determines the thickness of this popular finish. Because denatured alcohol dissolves shellac, it can be used to revive or remove an existing shellac finish.
In automotive and manufacturing circles, pure denatured alcohol is known for its powerful degreasing properties. Because it evaporates quickly, it is often used to clean and degrease metal, leaving behind a clean, dry surface without risking corrosion. It can also be used to break down glue.
When diluted with water, denatured alcohol effectively removes mold and mildew growth, cleans windows without leaving streaks behind, and can even remove ink stains from clothing.
This versatile chemical compound can cause irritation upon exposure to the skin. Inhalation of denatured alcohol fumes can cause dizziness and nausea. Ingestion of this toxic substance is extremely dangerous and requires the attention of poison control.
Like all alcohols, denatured alcohol is highly flammable, and should never be used or stored near sources of heat, ignition, or open flames. Take care to ensure a well-ventilated working area when using denatured alcohol, and always protect yourself with safety glasses and chemically resistant gloves.
Acetone vs Denatured Alcohol
These two chemical compounds have many similarities, and can be used for the same purposes in some instances. However, they are also distinctly different.
The primary similarities between denatured alcohol and acetone are their appearance, purpose, and the effect they have on finished wood.
Acetone and denatured alcohol are both naturally clear, watery liquids. Artificial coloring is often added to denatured alcohol due to regulations, and to acetone when it is sold as a cosmetic product for removing nail polish.
Both acetone and denatured alcohol are used as fuel additives. They are both degreasers, cleaners, and useful in the production of petroleum products. Both are considered solvents, due to their capability to dissolve various substances.
Effect On Clear Wood Finish
Acetone and denatured alcohol can both be used to strip the finish off wood. Either solvent will help remove lacquer, varnish, shellac, or polyurethane, although stronger products such as lacquer or varnish stripper might be necessary in some cases.
These two compounds are chemically distinct and have different effects, though their purposes overlap.
Acetone is a non-toxic, naturally occurring organic compound. Denatured alcohol is a highly toxic manufactured substance made from ethanol and other additives. Acetone is safe enough to be used in pharmaceutical applications, while denatured alcohol is poisonous.
Effect On Plastic
Because many plastics are formulated using acetone or acetone-like compounds, exposure to acetone can have a damaging effect on some plastics. Denatured alcohol is safe for cleaning plastic.
Major Differentiating Factor
The biggest difference between these two solvents is the materials and substances they are capable of dissolving.
Either substance will remove grease or adhesive.
Denatured alcohol will strip clear, film-forming finishes. It will not dissolve paint.
Acetone not only eats through varnish, shellac, lacquer, and polyurethane, it will dissolve most paints and many plastics.
When to Use Acetone
Use acetone to remove melted polystyrene, PVC, or similar plastics.
Pure acetone can be used to thin lacquer and significantly speed dry time, reducing the risk of streaks and drips. When combined with other solvents in lacquer thinner, acetone helps change the viscosity of the finish without speeding the dry time too much.
Acetone is the first substance you should turn to when confronting stubborn stains on porcelain. Rings around the tub or the bottom of a coffee cup will disappear after being soaked with acetone and water.
When to Use Denatured Alcohol
Use denatured alcohol to clean plastic, and for DIY or woodworking projects that include shellac.
Denatured alcohol is one of the key ingredients in shellac (the other being lac resin). It can be used to thin shellac to the appropriate viscosity, to clear up mistakes made in application, to refresh a tired shellac finish, or to remove shellac entirely.
Denatured alcohol should also be used when household plants have a mealybug or red spider mite infestation.
Which Is Better, Acetone or Denatured Alcohol?
Denatured alcohol is better when you want to dissolve a clear finish without disturbing the paint underneath, and for cleaning plastic.
Acetone is better for stripping paint, removing melted plastic, and cleaning porcelain.