Sandpaper

https://en.wikipedia.org/wiki/Sandpaper

Generally has a paper (cheapest) backing bonded with glue

Common paper:

• Aluminium oxide cloth
• Silicon carbide paper

Backing Material

Paper weight categories A -> F, with F being the heaviest. (no B).

For electric sanders, paper is reinforced w/ cloth fiber/resin/etc.

Alternatives

• Cloth (J, X, Y, YY), add F for "flexible"
• PET film (1 -> 7)
  • durable
  • even thickness, cleanest
• Vulcanized fibre
  • durable
  • thick/strong so used only for sanding disks

Wet/dry (wet and dry) paper is coated in latex

• best used when wet because particles washed preventing clogging

Abrasive Coating

Flint is mostly used in the past, which is crystals from quartz (SiO4). But is too soft for most sanding.

• Synthetic grit mostly made of aluminum oxide (AlO) is used. Suitable for wood \& metal.
• Alumina zirconia is used for ceramic materials. More expsnive, but sharper + lasts longer
• Silicon carbide is used for wet sanding and has very fine grit sizes available.

Size

Range:

• Course (~= 2mm)
• Ultrafine (<1 um)

Sandpaper can be either closed coat or open coat.

• 90% surface coverd in closed vs
  • better for harder materials
• 50% covered in open
  • more flexible so prevents clogging
  • less even during polishing