Part 1 of
the Exterior Story focused on shaping the window pane (Link: Replacing the Leaking
Quarterberth Port, the Exterior Story –
Part 1.) Thanks to everyone the left suggestions and
links on the last post. Now we are on to
installing the window.
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| Drilling over-sized holes for fasteners in the acrylic window pane. |
Due to
thermal expansion / contraction the pilot holes for mechanical fasteners need
to be over sized. I also drilled a
slight counter sink on the exterior pilot holes to provide space for butyl tape
bedding. This work was all done on a
drill press.
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| Clamping window in place to test fit, mark fastener locations, and scribe window opening on interior face. |
The window
moved from the drill press to a test fit on Pilgrim. While the window was clamped in place we
marked the fastener locations on the exterior.
On the interior we used a marker to
trace the window opening onto the
masking.
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| Using a marker to trace the interior window opening onto the masking. |
After
removing the pane, we gently ran a razor blade along the outline of the opening
on the interior of the window. This
allowed us to remove the section of masking in contact with the hull while
leaving the remaining window masked. We
then drilled the pilot holes the cockpit wall.
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| Acrylic in contact with hull exposed and pilot holes drilled. |
We are using
#12 stainless steel pan head screws to mount the window. To allow for thermal expansion we included a
neoprene washer between the head of the screw and the pane of acrylic. The screws are bedded with butyl tape. We are also using butyl tape to bed the
window.
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| Applying butyl tape to fasteners and acrylic. |
We applied
three rings of ¾” wide X 1/8” thick butyl tape to the exposed acrylic on the
interior face of the pane. We have found
Amazon to be a good source for butyl tape.
Here is a link to the tape we are using on this project – Dicor Butyl Tape.
Fortunately
the installation occurred on a hot, sunny day.
Both the acrylic and the butyl tape are easier to work with when they
are warm. In cold temps the acrylic is less
flexible and more prone to cracking. The
cold butyl tape is much more firm and less likely to form into a good seal. If completing this project in the winter, then
we would have used a heat gun to warm the assembly prior to attempting the
installation.
The
installation went smoothly. We over
tightened the pane slightly until we observed butyl tape squeezing out around
the entire perimeter. Then we backed off
the screws until the neoprene washers returned to their original shape (
approximately ¼ to ½ a turn.)
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| Using a plastic "knife" to remove the excess butyl tape |
We use a
plastic “knife” to cut away the excess butyl tape.
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| The completed installation. |
After
completing the install, overnight thunderstorms confirmed the new window is
water tight.
See our Cockpit Refit Photo Album for additional images and other projects associated
with the cockpit.




















