A website about constructing metal book clasps, bosses and other types of book hardware, showing examples of book clasp repair and restoration and information on workshops offered by Joycelyn Merchant on the design and construction of metal bookclasps.
Two
volumes, part of a larger set of New Testament  commentaries
from 1734, bound in wooden boards and covered in vellum. Each was
originally fitted with two brass clasps with brass hasps. One needed
a replacement clasp on the top, two clasps/hinges on the bottom. New
hasps were needed for both volumes. |
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 Title page of volume. |
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| The
Repair |
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 In
order to get an accurate pattern for the clasp, a rubbing was taken
of one of the remaining clasps on the volume. Twenty gauge (20#)
brass was used to make the new clasps and 22 gauge for the hasps.
The rods used to make the catches on the clasps were quite heavy,
so 12 gauge brass wire was used to make them and also to make the
hinge pins.
A jeweler's saw was used to saw the clasps,because the metal was quite heavy. Clasps were beveled and decorated to match the originals, with holes drilled appropriately. Hasps were measured and hammered to match existing hasps, and then they were hinged to the bottom clasp parts. Photos show various states of completion. Clasp parts were then given a brushed finish, (upper left pic) and then scrubbed clean using an abrasive cleaner to remove any traces of oil before the patina was applied. |
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Attaching
the Clasps |
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Before the clasps could be affixed to the book the paper paste downs were lifted to provide access the boards. The last vestige of the old rivets was removed and the old holes which held the rivets was repaired. Paste downs were repaired with a little thin Japanese paper. To repair the holes in order to make it possible to rivet the new clasp back on securely, a drill bit the same size as as a small hardwood dowel rod was used to drille through the existing hole in the board. The rod was trimmed to approximately the right length and then glued into the hole using Elmer's wood glue. When the glue was dry the rods were carefully sanded flush with the inside board surface. |
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The clasps were matched up with the old marks on the leather. New holes were drilled into the boards, and the new parts were riveted back on. Some final adjustments were made to the hasps until everything clasped properly. Final results are shown above, and on the right. The repaired volume is on the top in the picture above, and on the right in the photo on the right. |
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Clasps
of brass, or possibly bronze were originally attached to the boards
with what looked like headless rusty nails for rivets. The clasps
had a dark patina, possibly intentional, or possibly only due
to age. I used the complete clasps on the other volume as a reference
for modeling the new clasps and hasps. These were large, hefty
volumes, at least 12" X 15" and about 3" thick.
Metal
used in the original clasps was heavy, about 20 gauge. The hasp
was a lighter gauge, and was not flat but was hammered down its
length to give it a curved, raised look. This was done most likely
provide more stability in the hasp. 
The
old clasps left some verdigris stains, (left), which were
not removed. No other cleaning of the leather was done.
Finally,
all the parts were colored with a commercial patina solution to
give them a dark finish. Here are two close-up views of one of the
finished replacement clasps.
