MICROTOMY: MICROTOME KNIFE SHARPENING: HONING

- GLASS PLATES:

hand sharpening readily available, cheap

- GLASS PLATES:

surface roughened to enable particles of abrasive to adhere to the glass. easily cleaned after use

- COPPER AND BRONZE PLATES:

automatic knife sharpening machines expensive, superior properties.

MICROTOME KNIFE SHARPENING

- manual procedure or automatic procedure

Abrasive grinding of the facets (HONING)

- naturally occurring slabs of stone with varying abrasive properties"

Aluminum oxide (alumina) Iron oxide (Jeweller's rouge) Silicon carbide Diamond

ABRASIVES ????

STONES:

Belgian black vein and Arkansas, aloxite and carborundum- composites - lubricated with soapy water or light oil during use.

'back' Hone

MANUAL METHOD Knife with a ___________ effectively raises the non-cutting edge up off the hone. Back of the knife is ground simultaneously with the edge, hence reserved for use only with that particular knife. ___________ is placed on the bench on a non-skid surface (damp cloth) to prevent moving during honing.

light oil Abrasive

MANUAL METHOD Small quantity of ____________ or soapy water applied to the hone and smeared over the surface. ____________________ is applied to the glass or metal plate. Knife with handle and backing sheath is laid on the hone with cutting edge facing away from the operator, heel roughly in the centre of the nearest end of the hone. Handle of the knife is held between the thumb and the forefinger.

Thumb and forefinger heel to toe figure of eight

MANUAL METHOD ______________________ of the other hand rest in the other end of the knife to ensure even pressure along the whole edge of the knife. Knife is pushed forward diagonally from_____________________, turned over on its back and moved across the hone until the heel is in the centre with the cutting edge leading and then brought back diagonally. It is then turned over on its back and moved across the hone to its original position completing ___________________movement.