thumb|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.

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.

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

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. These alternatives are less effective than strippers 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 or more create toxic lead fumes in lead-based paint, but low-temperature heat guns and infrared paint removers do not create lead fumes. 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.

Safety

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

Many traditional paint strippers were or are based on dichloromethane, which can pose serious health risks and is banned in the United States and European Union for consumer use. Deaths from dichloromethane were rare at fewer than 2.4 cases per year and associated mostly with users applying large amounts in confined, poorly ventilated spaces.

Removing old lead-based paint can disperse lead and cause lead poisoning; some U.S. regulations address removal of old paint that could contain lead.

See also

  • Distressing
  • Nitromors

References

  • JAIC 1993: The composition of proprietary paint strippers
  • Old-House Journal article on paint removers starts on page 58
  • "How To Use Paint Stripper", an explanation on usage of paint strippers
  • Remove Old Paint from Walls