Paint stripper

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Paint remover is applied to an aircraft's landing gear during an inspection looking for cracks in the aluminum USMC-120605-M-YE163-007.jpg
Paint remover is applied to an aircraft's landing gear during an inspection looking for cracks in the aluminum

Paint stripper or paint remover is a chemical product designed to remove paint, finishes, and coatings, while also cleaning the underlying surface. Chemical paint removers are advantageous because they act on any kind of geometry and they are cheap. They can however be slow acting. [1]

Contents

Paint can also be removed using mechanical methods (scraping or sanding) or heat (hot air, radiant heat, or steam).

Types

The selection of chemical paint removers is based on the chemical bonds that form the paint's binder. Two basic categories of chemical paint removers are caustic and solvent.

Caustics

Caustic paint removers, typically aqueous sodium hydroxide (also known as lye or caustic soda), work by breaking down the chemical bonds of the paint, usually by hydrolysis of the esters that comprise the paint film. [1] Caustic removers must be neutralized or the new finish will fail prematurely. In addition, as caustic paint strippers typically include corrosive active ingredients, several side effects and health risks must be taken into account in using. Caustic aqueous solutions are typically used by antique dealers who aim to restore old furniture by stripping off worn varnishes, for example.

Solvents

Solvent-base paint strippers can be complex mixtures of various organic solvents, emulsifiers, thickening agents, alkaline or acid active ingredients as well as evaporation and corrosion inhibitors. Dichloromethane, also called methylene chloride, was once a popular solvent, but its use has been declining because of health concerns. [1] Traditional solvent paint strippers penetrate the layers of paint and break the bond between the paint and the object by swelling the paint. [2]

Aside from dichloromethane, some popular stripping solvents are N-methylpyrrolidone, dimethylformamide, benzyl alcohol, and dimethyl adipate. None of these are chlorocarbons. [3]

Paint strippers come in a liquid, or a gel ("thixotropic") form that clings even to vertical surfaces.

Solvent strippers may also have formulations with limonene (obtained from orange peels) (or other terpene solvents). Nitromethane is another commonly used solvent. Dimethyl sulfoxide is a less toxic alternative solvent used in some formulations. Unfortunately, these alternative stripping formulas are less effective compared to those based on dichloromethane.

Alternatives

Heat guns are an alternative to chemical paint strippers. When heated, softened paint clumps and is easier to contain. High-temperature heat guns at 1,100 °F (590 °C) or more create toxic lead fumes in lead-based paint, [4] [5] but low-temperature heat guns and 400 °F (200 °C) infrared paint removers do not create lead fumes. [6] Fire is a possible hazard of using heat guns.

Steam can be used on large surfaces or items to be stripped, such as window sash, can be placed inside a steam box. [7]

Safety

A product's material safety data sheet can provides more safety information than its product labels.

Many traditional paint strippers were or are based on dichloromethane, which can pose serious health risks. [8] It is likely a carcinogen, [9] and is banned in some countries for consumer use. [10] Despite this, deaths from dichloromethane are extremely rare at fewer than 2.4 cases per year [11] and associated mostly with users applying large amounts in confined, poorly ventilated spaces. When applied in reasonable amounts and with typical levels of ventilation, or outdoors, it is generally safe to use.

Removing old lead-based paint can disperse lead and cause lead poisoning, leading several US workplace and environmental regulations address removal of old paint that could contain lead. [12]

See also

Related Research Articles

<span class="mw-page-title-main">Paint</span> Pigment applied over a surface that dries as a solid film

Paint is a material or mixture that, when applied to a solid material and allowed to dry, adds a film-like layer. As art, this is used to create an image or images known as a painting. Paint can be made in many colors and types. Most paints are either oil-based or water-based, and each has distinct characteristics.

<span class="mw-page-title-main">Solvent</span> Substance dissolving a solute resulting in a solution

A solvent is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules, and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell.

<span class="mw-page-title-main">Haloalkane</span> Group of chemical compounds derived from alkanes containing one or more halogens

The haloalkanes are alkanes containing one or more halogen substituents. They are a subset of the general class of halocarbons, although the distinction is not often made. Haloalkanes are widely used commercially. They are used as flame retardants, fire extinguishants, refrigerants, propellants, solvents, and pharmaceuticals. Subsequent to the widespread use in commerce, many halocarbons have also been shown to be serious pollutants and toxins. For example, the chlorofluorocarbons have been shown to lead to ozone depletion. Methyl bromide is a controversial fumigant. Only haloalkanes that contain chlorine, bromine, and iodine are a threat to the ozone layer, but fluorinated volatile haloalkanes in theory may have activity as greenhouse gases. Methyl iodide, a naturally occurring substance, however, does not have ozone-depleting properties and the United States Environmental Protection Agency has designated the compound a non-ozone layer depleter. For more information, see Halomethane. Haloalkane or alkyl halides are the compounds which have the general formula "RX" where R is an alkyl or substituted alkyl group and X is a halogen.

<span class="mw-page-title-main">Hot-dip galvanization</span> Process of coating iron or steel with molten zinc

Hot-dip galvanization is a form of galvanization. It is the process of coating iron and steel with zinc, which alloys with the surface of the base metal when immersing the metal in a bath of molten zinc at a temperature of around 450 °C (842 °F). When exposed to the atmosphere, the pure zinc (Zn) reacts with oxygen (O2) to form zinc oxide (ZnO), which further reacts with carbon dioxide (CO2) to form zinc carbonate (ZnCO3), a usually dull grey, fairly strong material that protects the steel underneath from further corrosion in many circumstances. Galvanized steel is widely used in applications where corrosion resistance is needed without the cost of stainless steel, and is considered superior in terms of cost and life-cycle. It can be identified by the crystallization patterning on the surface (often called a "spangle").

<span class="mw-page-title-main">Tetrachloroethylene</span> Chemical compound in very wide use

Tetrachloroethylene, also known as perchloroethylene or under the systematic name tetrachloroethene, and abbreviations such as perc, and PCE, is a chlorocarbon with the formula Cl2C=CCl2. It is a non-flammable, stable, colorless and heavy liquid widely used for dry cleaning of fabrics, hence it is sometimes called "dry-cleaning fluid". It also has its uses as an effective automotive brake cleaner. It has a mild sweet, sharp odor, detectable by most people at a concentration of 50 ppm.

<span class="mw-page-title-main">Dichloromethane</span> Chemical compound

Dichloromethane is an organochlorine compound with the formula CH2Cl2. This colorless, volatile liquid with a chloroform-like, sweet odor is widely used as a solvent. Although it is not miscible with water, it is slightly polar, and miscible with many organic solvents.

<span class="mw-page-title-main">1,1,1-Trichloroethane</span> Solvent, now banned for ozone depletion

The organic compound 1,1,1-trichloroethane, also known as methyl chloroform and chlorothene, is a chloroalkane with the chemical formula CH3CCl3. It is an isomer of 1,1,2-trichloroethane. A colourless and sweet-smelling liquid, it was once produced industrially in large quantities for use as a solvent. It is regulated by the Montreal Protocol as an ozone-depleting substance and as such use has declined since 1996. Trichloroethane should not be confused with the similar-sounding trichloroethene which is also commonly used as a solvent.

<span class="mw-page-title-main">Flux (metallurgy)</span> Chemical used in metallurgy for cleaning or purifying molten metal

In metallurgy, a flux is a chemical reducing agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time. They are used in both extractive metallurgy and metal joining.

<span class="mw-page-title-main">Cellulose acetate</span> Organic compounds which are acetate esters of cellulose

In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and as a frame material for eyeglasses; it is also used as a synthetic fiber in the manufacture of cigarette filters and playing cards. In photographic film, cellulose acetate film replaced nitrate film in the 1950s, being far less flammable and cheaper to produce.

<span class="mw-page-title-main">White spirit</span> Petroleum-derived clear, transparent liquid

White spirit (AU, UK and Ireland) or mineral spirits (US, Canada), also known as mineral turpentine (AU/NZ/ZA), turpentine substitute, and petroleum spirits, is a petroleum-derived clear liquid used as a common organic solvent in painting. There are also terms for specific kinds of white spirit, including Stoddard solvent and solvent naphtha (petroleum). White spirit is often used as a paint thinner, or as a component thereof, though paint thinner is a broader category of solvent. Odorless mineral spirits (OMS) have been refined to remove the more toxic aromatic compounds, and are recommended for applications such as oil painting.

Halocarbon compounds are chemical compounds in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms resulting in the formation of organofluorine compounds, organochlorine compounds, organobromine compounds, and organoiodine compounds. Chlorine halocarbons are the most common and are called organochlorides.

<span class="mw-page-title-main">Polyvinyl fluoride</span> Chemical compound

Polyvinyl fluoride (PVF) or –(CH2CHF)n– is a polymer material mainly used in the flammability-lowering coatings of airplane interiors and photovoltaic module backsheets. It is also used in raincoats and metal sheeting. Polyvinyl fluoride is a thermoplastic fluoropolymer with a repeating vinyl fluoride unit, and it is structurally very similar to polyvinyl chloride.

<span class="mw-page-title-main">Limonene</span> Liquid terpene hydrocarbon fragrance and flavor, extract of citrus peel

Limonene is a colorless liquid aliphatic hydrocarbon classified as a cyclic monoterpene, and is the major component in the essential oil of citrus fruit peels. The (+)-isomer, occurring more commonly in nature as the fragrance of oranges, is a flavoring agent in food manufacturing. It is also used in chemical synthesis as a precursor to carvone and as a renewables-based solvent in cleaning products. The less common (-)-isomer has a piny, turpentine-like odor, and is found in the edible parts of such plants as caraway, dill, and bergamot orange plants.

<i>tert</i>-Butyl alcohol Chemical compound

tert-Butyl alcohol is the simplest tertiary alcohol, with a formula of (CH3)3COH (sometimes represented as t-BuOH). Its isomers are 1-butanol, isobutanol, and butan-2-ol. tert-Butyl alcohol is a colorless solid, which melts near room temperature and has a camphor-like odor. It is miscible with water, ethanol and diethyl ether.

The chemical compound 1,2-dichloroethane, commonly known as ethylene dichloride (EDC), is a chlorinated hydrocarbon. It is a colourless liquid with a chloroform-like odour. The most common use of 1,2-dichloroethane is in the production of vinyl chloride, which is used to make polyvinyl chloride (PVC) pipes, furniture and automobile upholstery, wall coverings, housewares, and automobile parts. 1,2-Dichloroethane is also used generally as an intermediate for other organic chemical compounds, and as a solvent. It forms azeotropes with many other solvents, including water and other chlorocarbons.

<span class="mw-page-title-main">Powder coating</span> Type of coating applied as a free-flowing, dry powder

Powder coating is a type of coating that is applied as a free-flowing, dry powder. Unlike conventional liquid paint, which is delivered via an evaporating solvent, powder coating is typically applied electrostatically and then cured under heat or with ultraviolet light. The powder may be a thermoplastic or a thermoset polymer. It is usually used to create a thick, tough finish that is more durable than conventional paint. Powder coating is mainly used for coating of metal objects, particularly those subject to rough use. Advancements in powder coating technology like UV-curable powder coatings allow for other materials such as plastics, composites, carbon fiber, and MDF to be powder coated, as little heat or oven dwell time is required to process them.

<span class="mw-page-title-main">Hexamethylene diisocyanate</span> Chemical compound

Hexamethylene diisocyanate (HDI) is the organic compound with the formula (CH2)6(NCO)2. It is classified as an diisocyanate. It is a colorless liquid. It has sometimes been called HMDI but this not usually done to avoid confusion with Hydrogenated MDI.

<span class="mw-page-title-main">Dimethoxymethane</span> Chemical compound

Dimethoxymethane, also called methylal, is a colorless flammable liquid with a low boiling point, low viscosity and excellent dissolving power. It has a chloroform-like odor and a pungent taste. It is the dimethyl acetal of formaldehyde. Dimethoxymethane is soluble in three parts water and miscible with most common organic solvents.

Nitromors is a paint-stripping chemical intended for do-it-yourself use. It is manufactured in the U.K. by Henkel Consumer Adhesives of Winsford, Cheshire.

Sharkey Landfill is a 90-acre property located in New Jersey along the Rockaway and Whippany rivers in Parsippany, New Jersey. Landfill operations began in 1945, and continued until September 1972, when large amounts of toluene, benzene, chloroform, dichloroethylene, and methylene chloride were found, all of which have are a hazard to human health causing cancer and organ failure. Sharkey Landfill was put on the National Priority List in 1983, and clean up operations ran until the site was deemed as not a threat in 2004.

References

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  4. Reducing Lead Hazards when Remodeling Your Home. U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics. 1997.
  5. Petit, Georges, and Donald Grant. The manufacture and comparative merits of white lead and zinc white paints. London: Scott, Greenwood & Son;, 1907. 13. Print. This source states that lead vapors are given off around 400 °F (200 °C) http://www.mediafire.com/view/1xyimc3wdo3/manufacturecompa00petirich.pdf
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