Upper Hull - It was obvious even to the casual
observer that there was a sag in the hull
starting on the port side at amidships and
running back to the transom. The sagging
was caused by the structural failure of the
framing and planking and need to be repaired.
Using jack stands, string lines and a water level along the chine and under the main
frames the port side amidships back to the transom was
slowly raised a little each day until the sag was
removed. There was a short plank whose seam was open
and whose edge looked punkey. The plank was removed and
the inside horizontal seam-batten was found to be
rotting. That lead to the replacement of a second
plank, then a third and a fourth and so on.
It was interesting to find that with some previous repairs, the
repairer just casually counter sunk some of the screw holes and
never counter bored them. This left the screw head sitting almost at
the surface and after a sanding the screw head was showing.
There was a wide
assortment of fasteners found in the hull planking. They came in
slotted, Reed & Prince, Philips and
square-drive. The screw sizes included #7, 8, 10 and 12. Some
fasteners were bent and some were only held in place by years of
built-up hull paint.
Per the USCC publication NVIC 7-95 abandoned screw holes in the hull frames were re-drilled and then plugged with
hardwood dowels. The dowels were buttered with West
System 105 / 205 epoxy and then driven into the
screw holes. Later the top of the dowels were cut
off and the wood sanded smooth with 120-grit
sandpaper.
First, new mahogany seam-battens were
cut and fitted horizontal into the cutouts in the
main frames. Next vertical filler blocks were cut
and fitted vertically in between the horizontal
seam-battens. Finally, new 7/8" x 5 1/2" mahogany
planks were cut and dry fitted to the hull
framing. The new planks were cut to fit snug
along their length. The outside of the horizontal
seam-battens and the vertical ribs were coated
with 3M – 4200. In order to correctly fit
the new planks to the old ones wedges were cut
from 2 x 4" and then used in conjunction with
clamps to seat the new planking before fastening.
New #12 - 2 1/2" silicon bronze screws were then used to
refasten the planks to the main and intermediate
frames as well as the seam-battens. Butt blocks
were used to cover and seal the ends where two
planks butted up against each other. First, the
ends of the two planks were buttered with 3M
– 4200. Next, the butt blocks were fastened
in place with three silicon bronze carriage
bolts, washers and nuts. |
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