5 Liquids That Can Remove Dried Acrylic Paint From Surfaces
Drying of Acrylic Paint
Water-based acrylic paint uses an acrylic emulsion to bind pigment. Notice I said an emulsion, not a solution. The acrylic does not dissolve in water, and therefore an emulsion is created. When the water evaporates from acrylic paint, the polymer cross-links its molecules and forms an adherent acrylic-paint film. Once dry, the film is no longer water soluble. Therefore, to remove dried acrylic paint from a porous or nonporous surface, you will need a cleaner that is capable of dissolving acrylic resin. However, please take note: Some solvents and cleaners may not be appropriate for some surfaces and materials. This article will go over the appropriate surfaces for each cleaning liquid.
Before we really get into the various household chemicals useful in removing paint from various surfaces, I feel it prudent to mention a few words on safety. Most of the liquids mentioned here pose some kind of hazard to health and property.
The most important danger to consider here is flammabilty. Four of the five liquids featured in this article are moderately to extremely flammable. Remember to not use alcohols and solvents anywhere near naked flames or energized heating elements. The vapors of the most flammable, namely acetone and lacquer thinner, are heavier than air and can travel considerable distances to a source of ignition.
Most solvents are not only flammable but also nervous system depressants and may also be toxic. Special care in making sure adequate ventilation is provided when working with organic solvents. Also, ammonia is an irritant and can cause asphyxiation in closed spaces. If possible, it is best to work outdoors.
The next consideration is health concerns. These liquids can be dangerous:
- To inhale or ingest: You should only use solvents in well-ventilated areas. Ingestion or excessive inhalation can be extremely hazardous. Both the denatured alcohol and lacquer thinner may contain methanol, which is highly toxic by ingestion. It can cause blindness and even death!
- To touch: Do not allow contact between the solvent and your skin as the liquids will penetrate and get absorbed into your body. Ammonia solution also produces noxious vapors and can irritate the skin. Wear gloves and protective eyewear to mitigate accidental exposure risk.
Now that we have assessed the risk, we shall proceed better prepared and more informed.
Five Liquids That Clean Dried Acrylic
Non-porous surfaces, such as metal, glass, and plastics
Gives off intense fumes, dissolves brass (including the brass ferrules on paintbrushes and airbrushes), blackens aluminum, and should not be used on wood
Isopropyl alcohol, AKA rubbing alcohol
Both non-porous surfaces (including plastics and unvarnished, unpainted wood) and clothing
Has no common side effects, but infrequently causes irritation and redness on skin. As with all of these products, avoid topical contact
Non-porous surfaces, including plastics and unvarnished, unpainted wood
Contains methanol (a poison)
Non-porous surfaces, such as glass and metals. This is so strong it will not require much scrubbing (perfect for airbrush nozzle tips)
Gives off intense fumes—use in a well-ventilated area. Not safe for plastics or synthetic fabrics
Non-porous surfaces, such as glass and metals, and unvarnished, unpainted wood
Toluene and methanol are toxic; toluene can have long-term health effects. Look for thinners that contain ethyl acetate instead of toluene. Not safe for plastics
Note on Removing Acrylic Paint From Wood
Alcohol, acetone, and lacquer thinner should work on bare, unvarnished wood. If the wood is varnished and gets acrylic dried on it, then hot soapy water is the only way. Although alcohol will not strip varnish per se, it may dull the shine or discolor it.
1: Ammonia Solution
Good old cheap household ammonia is quite effective in removing semidry and dry acrylic paint from non-porous surfaces, such as metal, glass, and plastics. This is because ammonia is often used to stabilize acrylic emulsions by raising the pH. The sudsy variety might actually be best since it contains detergent to keep the loosened particles suspended for easier rinsing.
Be careful as the fumes can be intense. It might be best to clean with ammonia outdoors or under a fume hood or similar fume-extraction device. It's rare, but the fumes can also cause an allergic reaction.
Also, it bears mentioning that ammonia should not be used to clean airbrushes or regular paint brushes. It dissolves brass—including the brass plating on the ferrules of brushes—and blackens aluminum.
2: Rubbing Alcohol
Rubbing alcohol, also known as isopropyl alcohol, is effective in removing dried acrylic from not only non-porous surfaces but also clothing with a little elbow grease. It is another cheap and readily available cleaning solution. The 99% concentration works best, but I am sure the 91% and 70% would work fine too. Unlike ammonia, this liquid actually has some solvent action on the acrylic binder. Small stains on cotton and other natural fabrics should come out if they are soaked, then agitated with an old toothbrush.
How to Remove Acrylic Paint from Clothing With Rubbing Alcohol
Step 1: Gather Your Materials
You will need rubbing alcohol (the higher the concentration, the better) and a butter knife or old toothbrush.
Step 2: Soak the Dried Acrylic With Rubbing Alcohol
First, test the rubbing alcohol on a spot of the fabric that's not usually visible to make sure it will not remove any of the dye (this is uncommon, but it is always best to be safe). Then soak the paint stain with rubbing alcohol.
Step 3: Scrape off the Paint
Let the stain soak for about 15 minutes. By that point, the rubbing alcohol will have loosened the paint, so now you can scrape it off. Use your butterknife or toothbrush to separate the paint from the material.
Step 4: Repeat
Each time you do this, some of the paint will come off. It may take several applications to get the paint off entirely. For this sweatshirt, three applications were needed in order to remove the paint entirely.
3: Denatured Alcohol
Something that is a little stronger than isopropyl alcohol (rubbing alcohol) but still safe on plastics is denatured alcohol.
Denatured alcohol is stronger than isopropyl alcohol for two reasons:
- It does not contain water, unlike rubbing alcohol.
- It is composed of ethyl and methyl alcohol, which are stronger solvents than isopropyl alcohol.
One word of caution, though: Denatured alcohol contains methanol, which is a strong poison. Also, as with all alcohols, denatured alcohol is quite flammable. It burns with a very pale blue flame that is invisible in sunlight. Good ventilation and fire prevention are essential.
A stronger option would be acetone. Unlike alcohol, this powerful solvent cannot be used on plastics or synthetic fabrics. It really is only for getting into hard-to-reach areas where scrubbing is not possible. Acetone-safe surfaces are mainly nonporous, such as glass and metal. It is extremely flammable but low in toxicity. Most hardware stores, paint stores, and home improvement centers carry acetone in metal tins. Acetone is a common solvent used with fiberglass resins. I soak airbrush nozzle tips in acetone when they get gummed up with paint.
5: Lacquer Thinner
Lacquer thinner is a stronger solvent blend that would remove acrylics effectively from glass and metal. Unfortunately, lacquer thinner often contains toluene and methanol, which are toxic. Toluene is capable of long-term health affects. Lacquer thinner should only be used outdoors. Newer "green" formulations of lacquer thinner have eliminated toluene and replaced it with ethyl acetate, a low-toxicity solvent with a pleasant, fruity odor.