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Construction Notes |
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Skirt |
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skirt plug was made from 1/2" MDF sheet, each
panel being cut to profile and fitted to 3/4"
CDX ply top and bottom templates. |
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I cut holes
for the hemispheres into each panel before
putting the plug together - this made for more
accurate positioning of the hemispheres, but
proved to be a pain when it came to later
stages, including sanding, laying up and
painting. (next time...!!) |
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The plug was
finished with a 1/16" thickness of P40 filler,
sanded to a smooth finish using 600 grit wet &
dry, and this was given a coat of G4 sealer
which was sanded with 1200 grit wet & dry before
being given 6 coats of Carnuba wax and polished
to a high shine ready for laying up. |
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The plug was
fitted with a divider to allow for a two piece
mould, and a flange was created in order to bolt
the halves together. |
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The mould
was created in the usual manner, with gelcoat,
tissue and coarse mat to around 1/8" thickness,
but this was found to be a bit flimsy and I had
to add MDF strengtheners to the outside of the
mould to maintain the correct shape - it was
them holes again! |
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The final
casts were made in the usual way, with black
gelcoat, tissue mat and 6 layers of coarse mat,
all using black pigmented resin. |
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On
completion and on removal of the pieces from the
moulds, the holes for the hemispheres were
re-cut and cleaned up. |
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Hemispheres |
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A 100mm
acrylic two piece sphere was used to form the
core of the plug, which was profiled with an
inner lip for fixing to the inside of the skirt. |
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A fibreglass
mould was taken from this plug, and the casts
were made using black gelcoat, tissue and two
layers of coarse mat, using a black resin mix. |
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There are 56
hemispheres in the completed skirt - (and I only
made one mould! - months it took!) - The
hemispheres are fixed to the inside of the skirt
with black silicone sealant. |
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Hemisphere Rings |
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The rings
are resin castings made from an RTV100 rubber
mould. |
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A pattern
was turned in 1/2" MDF and mounted on an MDF
baseboard. This was surrounded by a 5" plastic
drainage pipe to form an outer edge to the mould
and 3" plastic pipe to form the inner edge. |
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Again, 56 of
these were needed - and these were fixed to the
outside of the skirt with black silicone
sealant. |
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Go to Part 9 -
base, mobility & audio |
