Caring for the whetstone

July 8, 2008

Here I will describe on how to use , maintain and care for the whetstones to make the most out of them . The actual sharpening process I will address on a separate thread.

First hand let me clarify some of the terms used which can be confusing. Wether one uses the terms , sharpening stone, honing stone, or whetstones one is speaking of the same thing. I guess the more appropriate technical term is whetstone. All sharpening/honing stones are whetstones.
A whetstone will require care and maintenance through out its life. It is most of the times just thrown together with tools in a haphazard way and totally neglected. It is in reality a precision instrument and to treat it in any other manner but as such will in fact render it useless for its real function . Sadly many carpenters are unable to have sharp tools and most times along with the lack of knowledge on how to achieve it , the condition of their whetstones is the culprit. It is also an investment for many such as myself where the price of a premium stone can be as much as $300.00. Nothing but good reasons to know how to take care of them.

First they should always have some type of enclosure to keep them from hitting other things and getting chipped or broken. Dust collecting on them is also not a good thing. Caked up dust will clog them preventing them from cutting. Most stones are rectangular in shape but some will be round. A whetstone is a precision tool and a reference for the tools it sharpens specially chisels and plane blades. It must be absolutely flat and straight both across and throughout its length. Corners must be sharp and free of chips .
Undoubtedly many of you have come across or own stones that are hollowed out along its length from wear. This is prevalent with man made stones which are always softer. Such a stone will actually ruin a chisel or plane blade by creating a rounded edge and worst ruining the back of a chisel which is the most important part if it. Said stone needs to be flattened out by grinding it on a flat steel or glass plate using compounds or some specialized sandpapers. That condition can actually be avoided by concentrating substantial more time on edges of stone while using it rather than in the middle of it. There are specific techniques while using them to maintain them flat. I will speak about that later.

Stones must be used with a lubricant wether it is a light oil, water or my favorite ,kerosene. Surface must always be totally wet with it. If not quickly the metal particles and stone particles will embed themselves in stone and reduce or eliminate its efficiency. After every use they should be totally cleaned and put in their boxes. Some I actually keep in a kerosene bath when not in use. Do not let the lubricant dry on stone after use. Wipe it clean.

Some will say to use a figure 8 motion while sharpening others straight back and forth and others in circles. The truth of the matter is all of these methods have to do with preserving the stone flat rather than the actual sharpening process although some benefit the tool more than others. Actually I use them all simultaneously during sharpening. The idea is to use all of the stone’s surface evenly and keeping it flat. Good idea but somewhat incorrect. The center of stone will always tend to wear more because as one approaches edges we naturally reduce pressure in the fear of slipping off ends. So I stay on the ends probably 75% of the time. I also flip stone end for end frequently so I don’t favor the closer end. Keep in mind stone also has two sides.

When sharpening narrow tools such as a 1/4” chisel for example there is always the possibility of rocking the tool and gouging the stone. Narrow tools like that can and should be done on the edge of stone if possible. That is where the 1” thick stone comes in real handy. Also when doing a carving gouge which will be rocked side to side it is best to use edge of stone.

Edges of stones are important. They should be sharp and crisp without nicks or chips. There are a few tools suck as 45 degrees parting tools and corner chisels that have to be honed riding with one wing off stone . A sharp edge will permit honing it right up to the very corner of tool.

Examples of badly used, maintained and kept stones;