How to keep your tools sharp – and why archaeologists might prefer you not to

First things first – this post will not tell you how to sharpen your tools.

The best advice I can give you – without showing you – about how to sharpen your (steel) tools is (a) read Sainsbury, J. (1984) Sharpening and Care of Woodworking Tools and Equipment   Burgess Hill: Guild of Master Craftsmen Publications Ltd.   The chapter on hand-tools is very useful, and the book has some great advice on grinding and sharpening equipment suitable for different types of workshop.

Then (b) take care over the quality of the materials that your tools are made of; poor quality materials won’t take and keep much of an edge.   And finally (c) learn through practice what it feels like to work with your edged tools, how they behave in different materials so you know what’s going on at the edge, and check your edges all the time.

So, back to how to keep them sharp.   I invest time in sharpening my edged tools.   The majority are steel (the rest bronze and flint), with a relatively high carbon content that among other things helps me to sharpen them by hand.

Most of my steel tools jumble around in a tool-bag, or when in use can be found lying around on my various chopping blocks or on the end of the shave-horse – recipe for disaster should anything fall to the floor!   Which is the main reason why I keep a thick layer of all the wood-shavings and chippings in the workshop.

But what about their storage and transport?   Most of the steel tools are odd shapes and sizes and whilst some came with sheaths, others have no protection.   Here is a selection of photos to demonstrate my solutions for keeping my tools sharp.   It’s easy to spot the home-made sheaths.

Nevertheless, imperfections in the cutting edges of tools can be revealing.   Maybe you’ve watched the TV CSI lab technicians match the tool marks in someone’s skull to potential murder weapons?   Remember how they work out which particular type of tyre iron, knife or blunt instrument was used to kill someone by comparing the shapes left in the victim’s bone with marks the CSIs thwack or stab into a suitable test material?

In theory you can do something similar in archaeology too.   An edged tool with a “ding”it it, like this one-

Edge damage on a small cleaver

Edge damage on a small cleaver

will leave a characteristic mark in the wood that it is used on.   Take my right-handed spoon knife.   In the photo below, you should be able to see the facets where I have used it to cut little chips away from a piece of birch; and inside the facets, thin, parallel lines which are left by the (currently damaged) knife edge.

Evidence for tool edge damage

Evidence for tool edge damage

Wouldn’t it be amazing to match up marks on prehistoric wood with the tools that were used to do the carving?  For example, some 9000 pieces of wood were recorded from the Area 6A excavations of the Bronze Age timber platform and trackway at Flag Fen (Peterborough, UK) (Taylor 2001:171).  Linking tools with timber at Flag Fen could throw light on ways that a major building enterprise was carried out and organised more than 3000 years ago.   In theory, the very chisel used to cut a mortise joint could be identified, and we could say “this tool was used to do that job”; just like the antler picks excavated from Stonehenge which were used to dig out the ditch and the holes for the standing stones.

In practice, it’s not so simple.   First, you need tools in order to study their edges.   Despite all that wood, the Flag Fen excavations revealed no more than one socketed gouge and one socketed axe-head (Coombs 2001:263, 265).   Why after all would anyone leave their tools behind?  Perhaps as part of a ritual, or accidental loss; but not if they are still needed for other activities.

In fact, many of what could be described as Bronze Age carpentry tools – especially axes – have been found in circumstances other than archaeological excavation; they were ploughed up by farmers or found by metal-detectorists, for example, with no associated timber to try to match to.   In any event, that timber will only be preserved if the underground conditions are right, like in the waterlogged peat at Flag Fen.   And archaeologically excavated examples of Bronze Age metalwork finds often show, by the careful positioning and arrangement of the objects, that the tools had been put in the ground in carefully deliberated ways (Barber 2003); in what archaeologists call hoards, and not necessarily associated with the timbers that tools might have been used on, nor abandoned in the workplace.

This raises an interesting question: were all Bronze Age carpentry tools intended for woodworking?   Metal – copper alloys and iron anyway, if not the precious metals – is often seen as “inherently utilitarian” (Barber 2001:164).   Yet sometimes there is evidence that tools had not been used.   For example, some of the axes from the Manton Copse 2 hoard found in Wiltshire in 1999 (and now in Wiltshire Museum) still bear their casting scars.   Were they “poorly finished” as described in the excavation report (Lawson et al 2011:35), or unfinished because they were never intended to be fettled and sharpened for carpentry?

Secondly, you need to be able to identify edge damage.   This could be difficult if the metal is corroded following thousands of years buried under the ground.   Or the object could have been damaged after it was buried, for example if hit by a plough share.   Some  imperfections, which could leave very characteristic marks, are nevertheless very difficult to see on the edge itself – like on my spoon knife, whose faults cannot be seen with the naked eye but are very obvious in the wood.

Thirdly, edge damage is easy to remove, and it is usually in the interest of the carpenter to re-sharpen and re-shape the edge.   Marks left in the wood might never be traceable to a tool which has been re-worked in this way.   There used to be a wonderful example of the reductive effects of sharpening on display in the Museum of St Albans, when the Salaman Collection was exhibited.   In the cabinet of sharpening equipment, a new chisel about 25cm long was shown alongside another of same make and original size, but which had been used and sharpened so much it is now only 10cm long.   The evidence would also disappear if the tool was recycled – melted down and turned into a new object.

That’s not to say that the study of prehistoric toolmarks is wishful thinking.   For example, 168 different axes were counted on the basis of the toolmarks left on the Flag Fen timbers.   Comparison of the toolmark shapes with the dimensions of different types of British Bronze Age axe led Maisie Taylor to conclude that socketed axes had been used to do the wood-working at the site (Taylor 2001:194-202).   More recently, photogrammetric and GIS techniques have been applied to the analysis of toolmarks on hewn prehistoric timber (Kovacs and Hanke 2012, 2013).

And finally…what might we conclude from the description of the Flag Fen scoop, carved from a piece of willow; “The bowl of the scoop was shaped across the grain and so well finished that no clues survive as to the method of fabrication.” (Taylor 2001:226)?

 

Barber, M. (2001) “A time and a place for Bronze”  In Brück, J. (ed)  Bronze Age Landscapes, Tradition and Transformation   Oxford: Oxbow Books

Barber, M. (2003) Bronze and the Bronze Age   Stroud: Tempus

Coombs, D. (2001) “Metalwork”   In Pryor, F. (et al) The Flag Fen Basin: Archaeology and Environment of a Fenland Landscape   Swindon: English Heritage

Kovács, K. and Hanke, K. (2012) “Hydrologic and feature-based surface analysis for tool mark investigation on archaeological finds”   International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences Volume XXXIX-B5:565-570

Kovács, K. and Hanke, K. (2013) “Automatic tool mark identification and comparison with known Bronze Age hand tool replicas”  ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences Volume II-5/W1:181-186

Lawson, A.J., Robinson, P. and Swanton, G. (2011)  “Bronze Age metalwork from Manton Copse, Preshute, Wiltshire”  Wiltshire Studies 104:31-43

Sainsbury, J. (1984) Sharpening and Care of Woodworking Tools and Equipment   Burgess Hill: Guild of Master Craftsmen Publications Ltd

Taylor, M. (2001) “The Wood”  In Pryor, F. (et al) The Flag Fen Basin: Archaeology and Environment of a Fenland Landscape   Swindon: English Heritage

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2 thoughts on “How to keep your tools sharp – and why archaeologists might prefer you not to

  1. Pingback: The cutting edge – more on toolmarks | artefactual

  2. Pingback: Sarsen #5 | artefactual

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