All craftspersons should have the knowledge and skill to be able to sharpen the tools they use. I say should because I am aware that many folk now rely on disposable blades for all their edge-tool requirements.
It does not take much experience, in any craft, to learn that blunt tools result in reduced quality of work. Lost time in re-cutting or forcing a cut is more than compensated for by time spent sharpening ~ or changing ~ blades.
I say all this from many years of laziness over the matter, and am spending time discussing it all at some length because I am aware of much ignorance in this area.
Next I must make mention of the quality of steels ~ briefly because I am not an expert on this, but the basics are important. Readers are advised to browse the notes by way of background, and then to leave further involvement to the specialists.
Then I explain the stages of sharpening bladed tools, such as knives, chisels, plane blades, and curved blades and gouges. Most of these do need specialist treatment for a proper job. But the basic methods are common to all.
Finally ~ a mention of the not-so-usual items, such as scissors and axes, and also mention some of the 'not for home-sharpening' tools.
I once read an historical account of garment factory where the scissors' sharpener visited every week. The seamstresses knew the importance of sharp tools.
A farm labourer would hang a sharpening stone around his waist ready to re-sharpen his scythe every ten minutes or so. I am old enough to remember seeing it ~ and still have shudders to think of the way the hand swept to and fro across the huge and wicked blade ~ and also to think of the speed at which the grass stalks blunted the tool.
I recently watched a carpet layer at work in our small bathroom. Not only did I marvel at the skill of eye in cutting the bulky carpet 'just right' ~ and first time ~ but I noted that discarded four ~ disposable ~ blades from his knife in the space of twenty minutes. He did a neat job ~ quickly ~ aided by a very quick action blade-change knife.
Whilst browsing the WWW for suitably priced awls I came acros several comments such as ~ 'my awl was blunt, how do I sharpen it?' Similarly ~ 'Can I resharpen the blades on my disposable blade knife?'
I was taught carpentry at school, and that included learning to sharpen chisels, and ~ later ~ plane blades. Similarly at college we were provided with craft knives and expected to sharpen them regularly ~ hourlyif they had heavy duty. Although Stanley knives wee available they were regarded as an uneccesary expense and luxury ~ and possibly a danger to fingers.
My college training involved guidance on teaching classwork. I would not let youngsters use sharp knives except under close supervision. The suggestion is to have a desk under the eye of the supervisor with one sharp knife and rigid application of the instruction ~ 'Bring your work out and cut it here ~ one at a time.' Sadly that does mean queueing ~ but better than joining the queue at A&E. It not only reduces cut fingers it emphasises the importance of care with sharp things. In a similar way ~ lifejackets are to be worn even if sailing on a shallow pond.
Steel is a mixture of iron, carbon, and various other elements that can make it harder than simple 'carbon-steel'. Iron is far too brittle to withstand sharpening, hence the need to alloy with carbon. Excess carbon and other impurities are burnt-off in special furnaces, and replaced by other ingredients ~which are added to make specialist formulas suited to the consumer's needs. These have names ~ 'molybdenum steel' ~ and since there are so many nowadays areoften referred to by numbers ~ 'AR550 steel' ~ '13-8 stainless' ~ 'Shirogami Nokozai' ~ 'Damascus Steel'.
By way of example '430F' includes Steel, Chromium, Manganese, Silicon, Phosphorus, Sulphur, and Moylbdenum.
Some knife blades, today, boast that they are made from 'Damascus Steel'. This was used to make sword blades centuries ago. I did read, somewhere, that the formula for this has been lost. No-one these days knows what the ingredients, and proportions, actually were. It is now used ~ perhaps wrongly ~ as a synonym for being 'good stuff'. That, of course, depends on it being correctly sharpened.
I mention this because it presents several problems that need to be avoided, and serves as good introduction to other more specialist sharpening needs.
