Glass as a wood scraping tool has been long utilized by carpenters and
cabinet makers for producing a smooth and highly polished surface on
hardwoods.  Sandpaper will raise or score the grain creating an uneven
surface undesirable for a smooth applied finish.  Today you can buy steel
scrapers which are specially shaped and which have to be filed and edged
very carefully.

http://www.mcs.net/~brendler/oldtools/scraping/scraper.htm

I prefer to scavange a sheet of broken windown glass from the neighbor's
dumpster and use that instead (The New England frugality in me speaks! or
is it the lack of paying work that forces me to be creative?)

I learned from a guy who used pieces of window glass to scrape the final
finish, and having tried it many times, can assure you that it does work
wonderfully, with the right touch.  Chatter marks are a hazzard faced by
the inexperienced.  After a couple dozen strokes the glass edge does get
dull but you just cut the glass to create a new edge.  Usually the scrapers
are square or triangular, easily held in the hand, no more than 6 inches on
a side, and they must have ever-so-slightly curved (convex) sides so as to
keep sharp corners away from the wood.  Any flaw or waver in the edge will
make it useless and a new edge will need to be cut.  In cutting the edges
the glass cutter will leave a rough edge along the score which cannot be
used, but the opposite face will be sharp as a razor (it is a square break,
not bevelled).

I have also used concave breaks in window glass to scrape rounded or shaped
wood, but had slightly worse luck in trying to prevent chatter marks.  It
is also more difficult to cut the glass shape for small wood pieces,
although serendipitous use of a natural curve or chipping a proper blade
would be likely.

Thinking about what a project such as this would leave behind for an
archaeologist to wonder about, I recall that when I scraped down an oak
dining table a few years ago I left a very tell-tale pile of waste glass.
I started with a full 9 x 12 inch sheet of glass (first cut into four
pieces 4 1/2 by 6 inches) and by the time I had finished had scores of thin
strips and four small unusable pieces waste and used glass left in the end.
 The final stage of the tool afetr al reductions was about 4 inches by 1
inch, being used on all sides, and reduced on all sides, and then when too
small I reduced from the tow longest sides.  I ended up with a 1 inch by 4
inch piece which could not be efficiently reduced further and which showed
wear on all four sides.  The scraps were curved, 6 to 3 inches long, and
about a 1/4 inch wide, with heavy wear on only one edge (cutting mark on
the other side).  I could not use the concave curve for scraping of the
flat table surface so there was no wear on that edge.  A carpenter of the
19th century might be foreced by economy to make more efficient use of the
glass and cut smaller strips off when they resharpened, so actual size of
the scraps may vary frm what I created.

Kira's question infers that what they have found is flaking of glass,
similar to how a chert blade would be formed, to create a scraping edge.  I
have never heard of anyone using anything but flat window glass for this,
as the edge has to be perfectly true, but for small and curved profile
scraping I guess anything is possible.  Perhaps shards of thicker bottle
glass, with sharp points, was used to scrape into grooves and notches in
the wood.

Of course, there are a thousand secondary uses for such objects, even when
they are broken.  I think one of the main characteristics of today, rightly
earning us the title of a "throw-away" society, is that we have lost the
knowledge and imagination to make due with what we already have at hand.  I
am putting the finishing touches to a very solid and complex work bench in
my basement and it has cost me approximately $6.00 for some wood screws.
The rest, including all the lumber, a couple dozen of good re-used wood
screws, nuts, bolts, washers, hinges, drawer pulls, and shelving is
salvaged and free.  In the corner is a box of old window glass given to me
by the neighbor - it just waits for the next project.

        Dan W.


At 12:38 PM 1/25/01 -0500, you wrote:
>I have been analyzing a small historic artifact collection from northwestern
>Pennsylvania and have come across several examples of late historic/modern
>(post 1870) glass fragments that show evidence of usewear and edge
>preparation/retouch indicating use in a fashion similar to prehistoric
>Native American scraping tools. These artifacts were collected from a
>domestic refuse scatter loosely associated with a late nineteenth century
>farmhouse. Several of these glass fragments are from machine made glass
>containers, one glass fragment is manganese solarized, another is pink
>machine-pressed table glass common during the Depression. I am aware of
>worked glass on earlier sites, but the late date is puzzling. Though this
>could be the work of either Native Americans or Europeans, there are no
>known contemporary Native American settlements in this vicinity. Has anyone
>come across any reference to something like this on later European sites?
>Native American Sites?
>
>Kira Presler
>Kittatinny Archaeological Research, Inc.
>