Paint stripper
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Paint stripper or paint remover is a chemical product designed to remove paint, finishes, and coatings, while also cleaning the underlying surface.
The product's
Paint can also be removed using mechanical methods (scraping or
).Types
Chemical paint removers work only on certain types of finishes, and when multiple types of finishes may have been used on any particular surface, trial-and-error testing is typical to determine the best stripper for each application. Two basic categories of chemical paint removers are caustic and solvent.
Caustics
Caustic paint removers, typically aqueous
- Ammonia (NH3)
- Calcium oxide (CaO)
- Calcium carbonate (CaCO3)
- Sodium carbonate (Na2CO3)
- Potassium carbonate (K2CO3)
- Potassium silicate (K2SiO3, or related silicates)
- Potassium hydroxide (KOH)
Solvents
Solvent paint strippers penetrate the layers of paint and break the bond between the paint and the object by swelling the paint.[1]
The active ingredient in the most effective paint strippers is dichloromethane, also called methylene chloride. Dichloromethane has serious health risks including death, [2] is likely a carcinogen,[3] and is banned in some countries for consumer use.[4] Despite this, deaths from dichloromethane are extremely rare at less than 2.4 cases per year[5] 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.
Solvent strippers may also have formulations with
Paint strippers come in a liquid, or a
The principle of paint strippers is penetration of the paint film by the molecules of the active ingredient, causing it to swell; this volume increase causes internal strains, which, together with the weakening of the layer's adhesion to the underlying surface, leads to separation of the layer of the paint from the substrate.
Other components
Various co-solvents are added to the primary active ingredient. These assist with penetration into the paint and its removal and differ according to the target paint.
Colorants may be added.
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,[6][7] but low-temperature heat guns and 400 °F (200 °C) infrared paint removers do not create lead fumes.[8] 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.[9]
Local laws
See also
References
- ISSN 0094-0178.
- ^ MacIsaac, J., Harrison, R., Krishnaswami, J., McNary, J., Suchard, J., Boysen-Osborn, M., Cierpich, H., Styles, L. and Shusterman, D. (2013), "Fatalities due to dichloromethane in paint strippers: A continuing problem". Am. J. Ind. Med. doi: 10.1002/ajim.22167 http://onlinelibrary.wiley.com/doi/10.1002/ajim.22167/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false accessed 6/1/2013
- ISBN 978-1-4379-8736-2.
- ^ "Final Rule on Regulation of Methylene Chloride in Paint and Coating Removal for Consumer Use". United States Environmental Protection Agency.
- PMID 33871539.
- ^ Reducing Lead Hazards when Remodeling Your Home. U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics. 1997.
- ^ 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
- ^ Thomas, Baker, "All About Exterior Paint", "This Old House Magazine" 2012. http://www.thisoldhouse.com/toh/photos/0,,20586187_21145196,00.html
- ^ Old-House Journal. Active Interest Media, Inc.
- ^ Beckley, Bob; Groenier, James (December 2007). "Lead-Based Paint: Planning Your Paint Removal Project". T&D Pubs. United States Forest Service. Archived from the original on 2019-02-02.
External links
- JAIC 1993: The composition of proprietary paint strippers
- Old-House Journal article on paint removers starts on page 58
- "Urban Expression", a paper on the history of NYC graffiti.
- "How To Use Paint Stripper", an explanation on usage of paint strippers