Another one for any feedback before release to the wild....
Scrapers remove paint and dirt. Anyone can scrape, but a bad scraper
choice ruins surface finishes or makes work difficult.
==Hardness=Scraper behaviour is all about relative hardness. When 2 materials
scrape against each other, the softer one deforms, with little effect
on the harder one. This means 2 things:
* to be an effective cleaner the scraper must be harder than the dirt/
* to avoid risk of damage the scraper should be softer than the
Hardness is measured in mohs, a non-linear scale with with diamond at
10 mohs, and soft talc at just 1.
==Surface damage=With many surfaces, microscopic damage matters. It causes:
* loss of gloss or shine
for see-through materials, complete loss of clarity
* it makes cleaning rather harder, which is an issue in the kitchen,
and with plastic surfaces
gradual wearing off of thin surface coatings
===Wood==For some surfaces, microscopic damage doesn't matter. This is true of
wood, and thus metal scrapers are usually used. The tough hard steel
is long lived and rarely needs its edge grinding. Wood is low on the
mohs scale at under 2.5.
===Glass==Glass and see through plastic are especially vulnerable to scraper
action, since the results of surface damage are so visible. Glass is a
very hard material at 5.5 mohs, but steel scrapers can sometimes cause
scratching and abrasion as they're just as hard. Where glass is
puttied it doesn't matter, as its covered over, and tiny scratch marks
are a very small matter. Where the effects are more noticeable, steel
scrapers are better avoided. Copper and aluminium edges can remove
paint and dirt, albeit with a fair bit of wear to the scraper edge.
===Plastic==Plastics vary significantly in hardness, and are softer than metals.
Sometimes a thin softer plastic finish on a hard surface makes its
softness non-obvious - non-stick cookware is an example. Plastics also
frequently need to retain their shine to look good. For these reasons
only the softest of scraper material should be used occasionally on
plastic (eg wood & fingernails) with detergents & other chemical
cleaning methods much preferred. Clear plastics should not be scraped
at all, just one scraping session can ruin their appearance.
===Aluminium==Aluminium is a fairly soft material. It tends to become pitted in use,
and loss of shine on such surfaces is a non-issue.
====Linished===Linished aluminium has very shallow scratch marks in precise
alignment, and rearranging the pattern ruins the visual effect. Such
decorative surfaces should not be scraped. If there is no other option
for a one off situation, scraping should at least be done in accurate
alignment with the existing linish lines. A straight guide edge can be
used to help ensure aligned scraping.
====Polished====Polished aluminium should not be scraped at all. Any scraping can be
expected to visibly affect the surface. Chemical methods should be
used. In principle aluminium can be refinished after scraping, but
such refinishing isn't normally worthwhile.
===Stainless steel==May be scraped with aluminium or copper, or softer plastic scrapers.
Scraping with steel is ok where a fine finish isn't needed, but it
ruins the finish on stainless steel splashbacks, polished cutlery etc.
Copper scourers are a good general purpose cleaning scraper for steel.
===Plastic coated sinks==The surface is soft and should never be scraped. Chemical methods are
available for all the usual typers of muck. See [[Cleaning Sinks]].
===Steel scraper==* tough
* good where a fine surface finish doesnt matter
available in various blade shapes for removing paint from wood.
* 5.5 mohs
===Iron wool==* tends to cause rust staining where stored
splinters are a problem
* too hard for almost all modern surfaces
===Stainless steel scourer==* too hard for most modern surfaces
too weak a structure to get much pressure on the edges
* 5.5 mohs
===copper scourer==* good for cleaning steel
can also be used for exfoliation
* copper has some antibacterial effect
removes rust spots from steel
* 3-3.5 mohs
===Plastic scourer=* The softest of all scrapers.
Useful for general purpose cleaning
===finger nail==* 2.5 mohs, a fairly soft scraper
always to hand!
===plastic scraper==* soft scraper
removes weaker/softer forms of dirt
* always to hand: a cut edge on some plastic kitchen waste works if
you run out
===Aluminium scraper==* Small pieces of scrap sheet aluminium are convenient
2.5-3 mohs, softer than copper
* Useful for surfaces that wont tolerate anything harder
the scraping edge wears quickly in use
Blade scraper - large snapoff one, std stanley blade.
Plastic de-icer scraper - windscreen
Spoke/hook shave - no, wotsit called?
== hoc==Plastic: expired credit card, offcut of thermoplastic (eg from kitchen
Aluminium: offcut of sheet material.
Ad hoc bladed scrapers are usually blade plus mole wrench, but these
aren't recommended due to the ease of blade slippage and consequent
damage or injury.
==Power scrapers=Power scrapers use a vibrating metal blade.
==See Also=* [[Special:Allpages|Wiki Contents]]
[[Special:Categories|Wiki Subject Categories]]