There are different sizes and shapes of shaker tables. There
are at least two basic types and they are Finishing Tables and Roughing Tables.
The roughing tables are much larger than the finishing tables, at least 6’ X
14’ and finishing tables much smaller. This shaker table is presently on display at the Cave Creek Museum in Cave Creek, AZ.
The style shaker table that I’m going to be discussing is
the finishing table. This table was originally used at the Golden Reef Mine
millsite, 10-stamp mill on Continental Mountain. It was in bad shape with all of the major
timbers on its undercarriage rotted and the table top totally rotted away. The
restoration was a total rebuild.
The table top was originally a wood deck that was covered
with linoleum. Linoleum was discovered in 1855 in England and was brought to the US in 1872. Linoleum flooring is made
from natural materials like linseed oil, recycled wood flour, cork dust and
limestone. This material was used on kitchen floors in the 1950’s because it
was very water resistant, very resilient and provides a slick and durable surface.
Basic Shaker Tables The two basic deck types
are rectangular and diagonal. Rectangular decks are
roughly rectangle shaped with riffles parallel to the long dimension. Diagonal decks are irregular rectangles with riffles
at an angle (nearly diagonal). In both types, the
shaking motion is parallel to
the riffle pattern. The diagonal decks generally
have a higher capacity, produce cleaner concentrates, and recover finer sized particles.
The decks are usually constructed of wood and
linoleum, rubber or plastics usually cover the top of the deck. These materials have
a high coefficient of friction, which aids mineral recovery. Expensive,
hard wearing decks are made from fiberglass. Both the deck surface and riffles on these units are formed as part of
the mold. In operation, slurry consisting of about 25% solids by weight and is fed
with wash
water along the top of the
table.
Dis-assembly of the original Table The first thing that
needs to be done is to determine what parts need to be replaced. The table
frame can be made from metal or wood. In our case the frame was wood and needed
to be totally replaced. We made sure that we had several pictures of the frame below.
Drawings of the lower frame: You should make a
drawing of the frame to mimic the original layout of the base for easier
fabrication of the new beams.
Start assembling the new parts installing the
shaker boxes on the lower frame and the shaker box tops on the upper frame as
shown below:
The timbers must be bolted to the lower frame,
this includes the center timber
The shaker table needs to be placed back on the
lower frame and the driver mechanism needs to be repositioned and connected to
the upper frame. This requires that you bolt the mechanism on the two timbers and
then slide it into the lower frame as sown below:
A fiberglass shaker table top was donated to the
museum and that was fastened to the upper frame. This had to be fastened with elevator bolt
with flat tops. The table had to be countersunk to insure that the table
surface was flat without any high spots.
The table had to be re-epoxy
with a gray color epoxy and then several coats of clear epoxy was applied to
make the surface smooth and free from bumps, with exception of the riffles.
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