Scrapers remove material from a surface by pushing a hardened edge across it. In metalwork they are used for removing gaskets, paint, scale, spatter and old coatings without cutting into the base material.
Scraper type follows the surface and the material. Flat scrapers for flat surfaces, triangular scrapers for corners, hook scrapers for grooves and O-ring seats, and putty knives for soft material. Carbide-tipped scrapers hold an edge far longer than steel and are used on hard surfaces.
Edge preparation matters. A scraper works by having a fine burr on the edge, produced by honing — a sharpened edge without a burr will skate across the surface instead of cutting. Carbide scrapers are used as supplied or honed to a specific shape.
Care is needed around machined surfaces. A scraper can remove metal if used with too much pressure or at the wrong angle, and a gouged sealing surface will leak. For gasket removal on aluminium and soft materials, plastic scrapers are the safer choice.
