Monday, January 18, 2010

Sinew and Ergonomic Stone Tools

Here's a look at the completed sinew bound Palaeoeskimo tools. There are so many interesting little quirks in these tools' design and manufacture that I'm just going to talk about the 4 tools that were hafted with sinew and leave the 5 baleen wrapped reproductions for next time.

The new piece for me in this set is the stubby handled side scraper based on a 3900-3100 year old Saqqaq side scraper found at Qeqertasussuk in Greenland. I wasn't quite sure what to make of the handle from the drawings (last post), it kind of looks like the tools would be hafted crooked. The side scraper hafts I've made in the past look like scalpels and everything is in a straight line. If the reference drawings of the original artifact weren't so thorough I might have convinced myself that I'd assembled it wrong. But when its all fit together and you hold it - wow - its the perfect little scraping and carving tool. If Lee Valley ever starts selling stone tools, this would be the first in the catalog. When you grasp the tool to use it, the handle just disappears into your hand.

There are lots of Palaeoeskimo handles that I've thought of as "functional", "expedient", "symbolic", or "clever" but this is the first one that I'd describe as "ergonomic". Leave it to the Palaeoeskimos living in Scandinavia to come up with it. Side scrapers are such handy little tools, too. Prehistorically, this would have been the primary tool used to form all these wooden handles. Palaeoeskimo side scrapers are prefectly designed for scraping and shaping hard organic materials, like wood, antler or whalebone. Its kind of a crooked knife, cabinet scraper, small gouge and plane all in one.

To bind the stone tools to the handles I used sinew and hide glue. I tend to use Knox gelatine for hide glue, although I go through enough of it now that I've started getting bigger bags of the stuff from Lee Valley. Knox comes in handy individual use sized pouches. I dissolve one 7 gram pouch in about 80 ml of warm water. When you first mix it there tends to be air bubbles in the mixture, so I let it set for an hour or so, then microwave it for 12 seconds and slowly stir it again. If the bubbles are gone, then its ready to use. If the bubbles are still there I continue to let it set and reheat until they are gone. If you don't get rid of the bubbles the glue will dry frothy with the bubbles and holes still intact.

I described in an earlier post how to process sinew from a dried tendon to usable string. I've braided all my long sinew, but I still have a lot of shorter 6 inch lengths that are ideal for this sort of hafting. I pull apart the amount I need and chew it until it softens. You can soak it in warm water if you don't like holding sinew in our cheek for 10 or 15 minutes. I'm not sure why I don't use a little cup of warm water. To be honest, I think its because fishing around in the water for the wormy little wet sinews is kind of gross and once you suppress the gag reflex, it really doesn't taste that bad.

To set the blade In the handle I dip the hafting area of the stone in the runny hide glue (microwave the glue for 12 seconds on high if it has set and you need to make it liquid again) and press it into the handle. Then wrap the sinew tightly around the join. The sinew shrinks to about half its size as it dries so you don't need to wrap it too tightly and more sinew is better than not enough. The best part is it sticks to itself and there's no need for knots. Just smooth it down on itself and it will hold. If you need to add more sinew, just keep wrapping threads until you have enough.

If you are working from an artifact as reference, the width of the hafting area on the handle or the notches on the tool will give you an indication of how much binding material you'll need to add. You can tell the hafting area on a stone tool because it will be ground down a bit. A knapped edge is sharp enough to cut through sinew as it dries, so you need to abrade your hafting area.

It'll take several hours to set. I usually leave it overnight to dry and then put on a coat of hide glue over the dried thread the next day to seal everything in. Loose threads can be pressed into the new glue to hold them in place and if there are really unruly threads you can trim them off with nail clippers. Store unused glue in the freezer and microwave it when you need it again.

Pros, Hafting with Sinew:
  • Simple to use. No knots necessary.
  • Works perfectly with hide glue, cleans up with warm water.
  • Shrinks as it dries to form tighter bond.
Cons, Hafting with Sinew:
  • Water soluble. If you use your tool in a wet environment, then your lashings will dissolve. (Idea for a future experiment: its not really a Palaeoeskimo solution, but I think that one function of red ochre on Beothuk tools would be to help waterproof rawhide or sinew lashings.)
Here's the finished Palaeoeskimo reproductions. The stubby handled side scraper is based on Saqqaq artifacts and the scalpel hafted side scraper is more Groswater Palaeoeskimo. The Knife is a Groswater Palaeoeskimo Asymmetric knife hafted in an Avayalik Island inspired handle. The end scraper is a triangular endscraper that shows up at many different times in Palaeoeskimo collections.

Back to Front:
Saqqaq Palaeoeskimo Side Scraper (Spruce, Chert, Sinew, Hide Glue): $113 Cdn (tax inc.)
Groswater Palaeoeskimo Side Scraper (Spruce, Chert, Sinew, Hide Glue): $85 Cdn (tax inc.)
Groswater Palaeoeskimo Asymmetric Knife (Alder, Chert, Sinew, Hide Glue): $113 Cdn (tax inc.)
Palaeoeskimo Scraper (Spruce, Chert, Sinew, Hide Glue): $113 Cdn (tax inc.)

Photo Credits: Tim Rast

Photo Captions:
First, Palaeoeskimo reproductions hafted with sinew and hide glue
Second, Saqqaq style side scraper. My thumb and forefinger are pinched together in the working postion.
Third, The handle fits perfectly when I close my hand.
Fourth, Ready to haft - that's a big bag of sinew above the tools.
Fifth, Dried sinew ready to chew.
Sixth, dipping the hafting area of a scraper in hide glue before inserting into the wood handle
Seventh, wrapping the sinew into the groove of a Groswater Asymmetric knife (I usually use two hands, but someone had to hold the camera)
Eighth, The hafting area of the end scraper is bound by sinew
Ninth, Ready to go!
Tenth, The finished tools


  1. "Leave it to the Palaeoeskimos living in Scandinavia to come up with it."

    If I recall, Ikea used to trade them in the early Holocene as the "KRÅOKED HÅNND SKRÅPÖRD" for the equivalent of 1 reindeer pelt - taxes in.

  2. hmmm, that's an idea... I could use some reindeer pelts and it would save time on assembly if I used the Ikea model, I could just put a rock and a stick in a bag with an allen key.

    Seriously though, I wonder if people would want to buy some of these things unassembled and shipped with dry sinew, hide glue and assembly instructions?

  3. I'm not sure I want hide glue bubbling over on my stove-top, but there are probably people out there who would be interested in kits - if the success of your "Beer Bottle to Arrowhead" flintknapping kit is any indication.

    I boil my own hideglue: oo poo


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