Sandpaper
Overview
 
Sandpaper, also known as glasspaper, is a heavy paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....

 with abrasive
Abrasive
An abrasive is a material, often a mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away...

 material attached to its surface.

Sandpaper is part of the "coated abrasive
Coated abrasive
A coated abrasive is an abrasive grain bonded to a flexible substrate using adhesives. Common substrates are paper, cloth, vulcanized fiber, and plastic films and come in grit sizes range from very coarse to ultrafine...

s" family of abrasive products. It is used to remove small amounts of material from surface
Surface
In mathematics, specifically in topology, a surface is a two-dimensional topological manifold. The most familiar examples are those that arise as the boundaries of solid objects in ordinary three-dimensional Euclidean space R3 — for example, the surface of a ball...

s, either to make them smoother (paint
Paint
Paint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...

ing and wood finishing
Wood finishing
Wood finishing refers to the process of embellishing and/or protecting the surface of a wooden material. The process starts with surface preparation, either by sanding by hand , scraping, or planing. Imperfections or nail holes on the surface may be filled using wood putty or pores may be filled...

), to remove a layer of material (e.g. old paint), or sometimes to make the surface rougher (e.g. as a preparation to gluing
Adhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...

).
The first recorded instance of sandpaper was in 13th century China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 when crushed shells, seeds, and sand were bonded to parchment using natural gum.

Shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

 skin was also used as a sandpaper.
Discussions
Encyclopedia
Sandpaper, also known as glasspaper, is a heavy paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....

 with abrasive
Abrasive
An abrasive is a material, often a mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away...

 material attached to its surface.

Sandpaper is part of the "coated abrasive
Coated abrasive
A coated abrasive is an abrasive grain bonded to a flexible substrate using adhesives. Common substrates are paper, cloth, vulcanized fiber, and plastic films and come in grit sizes range from very coarse to ultrafine...

s" family of abrasive products. It is used to remove small amounts of material from surface
Surface
In mathematics, specifically in topology, a surface is a two-dimensional topological manifold. The most familiar examples are those that arise as the boundaries of solid objects in ordinary three-dimensional Euclidean space R3 — for example, the surface of a ball...

s, either to make them smoother (paint
Paint
Paint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...

ing and wood finishing
Wood finishing
Wood finishing refers to the process of embellishing and/or protecting the surface of a wooden material. The process starts with surface preparation, either by sanding by hand , scraping, or planing. Imperfections or nail holes on the surface may be filled using wood putty or pores may be filled...

), to remove a layer of material (e.g. old paint), or sometimes to make the surface rougher (e.g. as a preparation to gluing
Adhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...

).

History

The first recorded instance of sandpaper was in 13th century China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 when crushed shells, seeds, and sand were bonded to parchment using natural gum.

Shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

 skin was also used as a sandpaper. The rough scales of the living fossil
Living fossil
Living fossil is an informal term for any living species which appears similar to a species otherwise only known from fossils and which has no close living relatives, or a group of organisms which have long fossil records...

 Coelacanth
Coelacanth
Coelacanths are members of an order of fish that includes the oldest living lineage of Sarcopterygii known to date....

 are used by the natives of Comoros as sandpaper.

Boiled and dried, the rough horsetail
Equisetum hyemale
Equisetum hyemale , known in South Africa as snake grass, is a species of horsetail native to moist forests, forest edges and stream banks, swamps and fens throughout the Holarctic Kingdom.-Usage:...

 is used in Japan as a traditional polishing material, finer than sandpaper.

Sandpaper was originally known as glass paper, as it used particles of glass. Glass frit
Frit
Frit is a ceramic composition that has been fused in a special fusing oven, quenched to form a glass, and granulated. Frits form an important part of the batches used in compounding enamels and ceramic glazes; the purpose of this pre-fusion is to render any soluble and/or toxic components insoluble...

 has sharp-edged particles and cuts well, sand grains are smoothed down and did not work well like sandpaper made from glass. Cheap counterfeit sandpaper has long been passed off as true glass paper; Stalker and Parker cautioned against it in the 17th century.

Glass paper was manufactured by John Oakey
John Oakey
John Oakey was an English inventor and founder of John Oakey & Sons Ltd. a manufacturer of sandpaper and polishing materials....

's company in London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 by 1833, who had developed new adhesive techniques and processes, enabling mass production. A process for making sandpaper was patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

ed in the United States on June 14, 1834 by Isaac Fischer, Jr., of Springfield, Vermont
Springfield, Vermont
Springfield is a town in Windsor County, Vermont, United States. The population was 9,373 at the 2010 census.-History:One of the New Hampshire grants, the township was chartered on August 20, 1761 by Governor Benning Wentworth and awarded to Gideon Lyman and 61 others...

.

In 1921, 3M
3M
3M Company , formerly known as the Minnesota Mining and Manufacturing Company, is an American multinational conglomerate corporation based in Maplewood, Minnesota, United States....

 invented a sandpaper with a waterproof backing, known as Wetordry. This allowed use with water, which would serve as a lubricant to carry away particles that would otherwise clog the grit. Its first application was automotive paint refinishing.

Types

There are many varieties of sandpaper, with variations in the paper or backing, the material used for the grit, grit size, and the bond.

Backing

In addition to paper, backing for sandpaper includes cloth (cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....

, polyester
Polyester
Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...

, rayon
Rayon
Rayon is a manufactured regenerated cellulose fiber. Because it is produced from naturally occurring polymers, it is neither a truly synthetic fiber nor a natural fiber; it is a semi-synthetic or artificial fiber. Rayon is known by the names viscose rayon and art silk in the textile industry...

), PET film
PET film (biaxially oriented)
BoPET is a polyester film made from stretched polyethylene terephthalate and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties and electrical insulation.A variety of companies manufacture boPET and other...

, and "fibre", or rubber. Cloth backing is used for sandpaper discs and belts, while mylar is used as backing for extremely fine grits. Fibre or vulcanized
Vulcanization
Vulcanization or vulcanisation is a chemical process for converting rubber or related polymers into more durable materials via the addition of sulfur or other equivalent "curatives." These additives modify the polymer by forming crosslinks between individual polymer chains. Vulcanized material is...

 fibre is a strong backing material consisting of many layers of polymer impregnated paper. The weight of the backing is usually designated by a letter. For paper backings, the weight ratings range from "A" to "F," with A designating the lightest and F the heaviest. Letter nomenclature follows a different system for cloth backings, with the weight of the backing rated J, X, Y , T, and M, from lightest to heaviest. A flexible backing allows sandpaper to follow irregular contours of a workpiece; relatively inflexible backing is optimal for regular rounded or flat surfaces. Sandpaper backings may be glued to the paper or form a separate support structure for moving sandpaper, such as used in sanding belts and discs. Stronger paper or backing increases the ease of sanding wood, so good quality sand paper is much better than low quality sandpaper. The harder the backing material, the faster the sanding, the faster the wear of the paper and the rougher the sanded surface.

Material

Materials used for the abrading particles are:
  • flint
    Flint
    Flint is a hard, sedimentary cryptocrystalline form of the mineral quartz, categorized as a variety of chert. It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones. Inside the nodule, flint is usually dark grey, black, green, white, or brown in colour, and...

    : no longer commonly used
  • garnet
    Garnet
    The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives. The name "garnet" may come from either the Middle English word gernet meaning 'dark red', or the Latin granatus , possibly a reference to the Punica granatum , a plant with red seeds...

    : commonly used in woodworking
    Woodworking
    Woodworking is the process of building, making or carving something using wood.-History:Along with stone, mud, and animal parts, wood was one of the first materials worked by early humans. Microwear analysis of the Mousterian stone tools used by the Neanderthals show that many were used to work wood...

  • emery
    Emery (mineral)
    Emery is a very hard rock type used to make abrasive powder. It largely consists of the mineral corundum , mixed with other species such as the iron-bearing spinels hercynite and magnetite, and also rutile...

    : commonly used to abrade or polish metal
  • aluminium oxide
    Aluminium oxide
    Aluminium oxide is an amphoteric oxide with the chemical formula 23. It is commonly referred to as alumina, or corundum in its crystalline form, as well as many other names, reflecting its widespread occurrence in nature and industry...

    : perhaps most common in widest variety of grits; can be used on metal (i.e. body shops) or wood
  • silicon carbide
    Silicon carbide
    Silicon carbide , also known as carborundum, is a compound of silicon and carbon with chemical formula SiC. It occurs in nature as the extremely rare mineral moissanite. Silicon carbide powder has been mass-produced since 1893 for use as an abrasive...

    : available in very coarse grits all the way through to microgrits, common in wet applications
  • alumina-zirconia: (an aluminium oxide–zirconium oxide alloy), used for machine grinding applications
  • chromium oxide
    Chromium oxide
    Chromium oxide may refer to:* Chromium oxide, CrO* Chromium oxide, Cr2O3* Chromium dioxide , CrO2* Chromium trioxide , CrO3* Chromium oxide peroxide, CrO5* Mixed valence species, such as Cr8O21...

    : used in extremely fine micron grit (micrometre
    Micrometre
    A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...

     level) papers
  • ceramic aluminum oxide: used in high pressure applications, used in both coated abrasives, as well as in bonded abrasives.


Sandpaper may be "stearate
Stearate
Stearateis the anion form of stearic acid.Formula is C17H35COO−.-Examples:* Sodium stearate, Na* Calcium stearate, Ca2* Magnesium stearate, Mg2...

d" where a dry lubricant is loaded to the abrasive. Stearated papers are useful in sanding coats of finish and paint as the stearate "soap
Soap
In chemistry, soap is a salt of a fatty acid.IUPAC. "" Compendium of Chemical Terminology, 2nd ed. . Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford . XML on-line corrected version: created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN...

" prevents clogging and increases the useful life of the sandpaper.

The harder the grit material, the easier the sanding of surfaces like wood. The grit material for polishing granite slab must be harder than granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

.

Later abrading surfaces include long-life stainless steel sanding discs.

Bonds

Different adhesives are used to bond the abrasive to the paper. Hide glue
Animal glue
An animal glue is an adhesive that is created by prolonged boiling of animal connective tissue.These protein colloid glues are formed through hydrolysis of the collagen from skins, bones, tendons, and other tissues, similar to gelatin. The word "collagen" itself derives from Greek κόλλα kolla, glue...

 is still used, but this glue often cannot withstand the heat generated during machine sanding and is not waterproof. Waterproof or wet/dry sandpapers use a resin bond and a waterproof backing.

Sandpapers can also be open coat, where the particles are separated from each other and the sandpaper is more flexible. This helps prevent clogging of the sandpaper. The wet and dry sandpaper is best used when wet.

Shapes

Sandpaper comes in a number of different shapes and sizes:
  • sheet: usually 9 by 11 inches, but other sizes may be available
  • belt: usually cloth backed, comes in different sizes to fit different belt sander
    Belt sander
    A belt sander is a machine used to sand down wood and other materials for finishing purposes. It consists of an electrical motor that turns a pair of drums on which a seamless loop of sandpaper is mounted. Belt sanders can be either hand-held, where the sander is moved over the material, or...

    s.
  • disk: made to fit different models of disc and random orbit sanders. May be perforated for some models of sanders. Attachment includes pressure sensitive adhesive (PSA) and "hook-and-loop" (similar to velcro
    Velcro
    Velcro is the brand name of the first commercially marketed fabric hook-and-loop fastener, invented in 1948 by the Swiss electrical engineer George de Mestral...

    ).
  • rolls: known as "shag rolls" by many contractors
  • sponge: for tight places

Grit sizes

Grit size refers to the size of the particles of abrading materials embedded in the sandpaper. Several different standards have been established for grit size. These standards establish not only the average grit size, but also the allowable variation from the average. The two most common are the United States CAMI (Coated Abrasive Manufacturers Institute, now part of the Unified Abrasives Manufacturers' Association) and the European FEPA (Federation of European Producers of Abrasives) "P" grade. The FEPA system is the same as the ISO
International Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...

 6344
ISO 6344
ISO 6344 is an international standard covering the materials sizes and tests regarding sandpaper and other similar coated abrasives.It has three parts:* ISO 6344-1:1998: Coated abrasives, sizes and tests.* ISO 6344-2:1998: Macrogrit, P12 to P220...

 standard. Other systems used in sandpaper include the Japanese Industrial Standards Committee
Japanese Industrial Standards Committee
The is a standards organization and is the International Organization for Standardization member body for Japan. It is also a member of the International Electrotechnical Commission.The JISC establishes and maintains the Japanese Industrial Standards....

 (JIS), the micron grade (generally used for very fine grits). The "ought" system ({0, 00, 000, ...} aka {1/0, 2/0, 3/0, ...}) was used in the past in the US. Cheaper sandpapers sometimes use nomenclature such as "Coarse", "Medium" and "Fine", but it is unclear to what standards these names refer.

Grit size table

The following table, compiled from the references at the bottom, compares the CAMI and "P" designations with the average grit size in micrometres (µm).
Grit size table
ISO/FEPA Grit designation CAMI Grit designation Average particle diameter (µm)
MACROGRITS
Extra Coarse (Very fast removal of material, hardwood flooring initial sanding) P12   1815
P16   1324
P20   1000
P24   764
  24 708
P30   642
  30 632
  36 530
P36   538
Coarse (Rapid removal of material) P40 40 425
  50 348
P50   336
Medium (sanding bare wood in preparation for finishing, for gentle removal of varnish, also used for skateboard grip tape)   60 265
P60   269
P80   201
  80 190
Fine (sanding bare wood in preparation for finishing, not suitable for removing varnish or paint from wood, use for cleaning plaster and water stain from wood) P100   162
  100 140
P120   125
  120 115
Very Fine (sanding of bare wood) P150   100
  150 92
P180 180 82
P220 220 68
MICROGRITS
Very Fine (sanding finishes between coats) P240   58.5
  240 53.0
P280   52.2
P320   46.2
P360   40.5
Extra fine, start polishing of wood   320 36.0
P400   35.0
P500   30.2
  360 28.0
P600   25.8
Super fine (final sanding of finishes, final sanding of wood)   400 23.0
P800   21.8
  500 20.0
P1000   18.3
  600 16.0
P1200   15.3
Ultra fine (final sanding and polishing of thick finishes) P1500 800 12.6
P2000 1000 10.3
P2500   8.4

See also

  • Belt sander
    Belt sander
    A belt sander is a machine used to sand down wood and other materials for finishing purposes. It consists of an electrical motor that turns a pair of drums on which a seamless loop of sandpaper is mounted. Belt sanders can be either hand-held, where the sander is moved over the material, or...

  • Dremel
    Dremel
    Dremel is a brand of power tools known primarily for their rotary tools. The tools were originally developed by Albert J. Dremel, who founded the Dremel Company in 1932 in Racine, Wisconsin. In 1993, the company was purchased by Robert Bosch GmbH, and today it is a division of the Robert Bosch Tool...

  • Emery (mineral)
    Emery (mineral)
    Emery is a very hard rock type used to make abrasive powder. It largely consists of the mineral corundum , mixed with other species such as the iron-bearing spinels hercynite and magnetite, and also rutile...

  • Grinding machine
    Grinding machine
    A grinding machine, often shortened to grinder, is a machine tool used for grinding, which is a type of machining using an abrasive wheel as the cutting tool...

  • Particle size (grain size)
    Particle size (grain size)
    Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. This is different from the crystallite size, which is the size of a single crystal inside the...

  • Polishing
    Polishing
    Polishing is the process of creating a smooth and shiny surface by rubbing it or using a chemical action, leaving a surface with a significant specular reflection In some materials polishing is also able to reduce diffuse reflection to...

  • Sander
    Sander
    A sander is a power tool used to smooth wood and automotive or wood finishes by abrasion with sandpaper. Sanders have a means to attach the sandpaper and a mechanism to move it rapidly contained within a housing with means to hand-hold it or fix it to a workbench. Woodworking sanders are usually...

  • Sanding block
    Sanding block
    A sanding block is a block used to hold sandpaper. In its simplest form, it is a block of wood or cork with one smooth flat side. The user wraps the sandpaper around the block, and holds it in place...

  • Emery cloth
    Emery cloth
    Emery cloth is a type of abrasive that has emery glued to a cloth backing. It is commonly used in metalworking by hand. A finer, less commonly seen grade has a paper backing instead.-Grades:...

  • Crocus cloth
    Crocus cloth
    Crocus cloth is an abrasive sheet similar to sand paper or emery cloth but covered with a layer of very fine loose polishing or lapping compound rather than with bound grains of abrasive. "For final metal and gemstone finishing." It is available in various grades .- External links :...

  • Grind
    Grind
    The grind of a blade refers to the shape of the cross-section of the blade. It is distinct from the type of blade , though different tools and blades may have lent their name to a particular grind.Grinding involves removing significant portions of metal from the blade and is thus distinct from...


Further reading

  • Michael Dresdner (1992). The Woodfinishing Book. Taunton Press. ISBN 1-56158-037-6

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK