| Core
Mounts
Once
you extract your cores from the tree, what do you do with them? First, let
them air dry inside your straw. You may have to slit the straw if you use
plastic ones. Push them out gently (a bicycle spoke works great) and
maintain the order of the pieces if the core is broken up. Sometimes
they'll be complete cores, other times they've break up into several
pieces. That's OK. Now you need to mount the cores somehow...
Wyvona
Scarbrough is
part owner of Custom Woodwork by Billy Jack, which supplies core
mounts made of yellow poplar:
"We
have been supplying core mounting sticks for several research labs in the
lower US and Alaska for the past ten years or so. Dr. Ed Cook sent me a
sample and these are made to his specifications. They are made from yellow
poplar and are 3/8" x 3/8" by 4 feet in length. The present
price is 35 cents per linear foot plus shipping (ask for shipping prices
and details). The name of our business is CUSTOM
WOODWORK BY BILLY JACK. You may contact us by telephone at 601-928-3801,
by e-mail wyvona@bellsouth.net
or fax 601-928-3527.
We have added an additional size of core mounts - 19mm wide x 16mm high by
4 feet in length designed for holding 0.5" diameter cores used in
archaeological analyses as well as regular studies. These mounts are made
to the specifications approved by Dr. Henri D. Grissino-Mayer of the
University of Tennessee. The cost per linear foot is 75 cents plus shipping
(ask for shipping information and prices)."
Custom
Woodwork by Billy Jack
Wyvona Scarbrough
149 Breland Road
Perkinston, MS 39573
Phone: 601-928-3801
Fax: 601-928-3527
A
West Virginia company also makes core mounts for dendrochronological
research. They are 3/8-in. X 3/4-in. X 4-ft. with a beveled top containing
a semi-circular notch to hold samples and come neatly bundled in packages
of 500 linear feet. The producer sells them for $285.00 per 1000 linear
feet, made from clear yellow poplar which is easy to work with. Contact:
Dayton C. Gank,
Proprietor
Frame and Trim Molding
Terra Alta, WV 26764-9541 USA
304-789-5872
Rob Argent gives these
instructions for making core mounts:
- Buy 3 meter lengths of
9 mm X 9 mm hardwood from your local building supplier.
- Buy a router bit that
will cut a 6mm diameter semi-circular groove (such as a 6 mm
(1/4") Core Box Router Bit, e.g. Carb-I-Tool T408 in Australia).
- Find a table router in
your nearest wood machining workshop (i.e. a large machine with a
centrally placed router bit facing upwards and a flat top over which
the wood moves). It might be possible to use a hand-held router, but
it would need to be well set up so that the wood was very stable.
- Set up the bit in the
router, adjust the guides so that the groove will be cut centrally on
the wood face, and slowly cut the groove in the wood.
- Make sure that the bit
remains clear of swarf (woody debris).
Mounting your cores
The
grooves should be about the width of your cores. When gluing your cores, make
sure the core is aligned exactly as it was inside the tree. To do
this, look at each side of the core. You should see a shiny band alongside
each core representing wood cells that were "ripped"
longitudinally by your increment borer. These represent the sides of the
core. On conifers, you can look at the end of each core and you'll see the
vertical alignment of cells. Make sure the cells go up and down when you
mount the core. Pour Elmer's glue into the groove, and place the core
inside the groove. To make sure the core stays put while it's drying
(cores sometimes like to warp), wrap the core and core mount with string
(if you have individual core mounts) or masking tape. Alternatively, you
can place a weight on top of the core until it's dry.
Once
dry, it's best if you cut the cores so that each core has its own mount.
This way, you can slide the cores alongside each other under a microscope.
A band saw or table saw can easily do this, but it's best if the core
mounts are made and sawn before the cores are glued down. |
