Timepieces:Education & Repair
Repairing and Sizing Expansion Bands
A few basic procedures can expand your repair abilities and draw a
wider range of repair traffic
By David Christianson
Certified Master Watchmaker
President, American Watchmakers-Clockmakers Institute
Speidel's "Twist-o-Flex" and other expansion bands remain as
popular as ever your store no doubt sells or repairs many of them.
You may be called on to custom-fit an expansion band that comes with a new
watch. Other times the band breaks when a customer catches it on something,
and you have to replace it or if it's one of today's higher-priced
versions repair it. Sizing the band and repairing the links are performed
using the same basic procedures.
Expansion bands are made of a series of bottom and top rectangular, tube-shaped
links holding two leaf springs and four U-shaped clips per link. On top
is a decorative cap.
To start the repair, you'll need a thin knife blade. Place the blade
behind the flat end of a link and twist outward while pushing toward the
fold in the hinge (see below). To remove the U-clips, use the knife to lever
open the end of a top cap on one link and then open the opposite end on
the bottom link on the adjoining link. Slide the two halves apart and the
U-clips will be clear to grasp with tweezers.
Another method is to open the ends on both sides of the top cap and adjacent
bottom link. Using tweezers, slide out the connected U-clips.
(Note: Several Speidel expansion bands require complete removal of the top
caps before replacing a link. These have larger top caps or an angled end
flap. If in doubt, refer to the watch company's repair guides.)
||To begin the repair, use a thin knife blade to pry open the
flat end of the link.|
To replace the U-clips after sizing or repair, line them up. Be sure
the clip on the bottom link inserts above the leaf spring in the top cap.
Also be sure the clip from the opposite end inserts below the leaf spring
on the bottom link. Slide the two links together. This can be tricky, but
you'll be able to do it in fewer than 10 minutes with practice.
When closing the ends of the links, support one side on your bench top.
Apply even pressure as you rotate your blade downward. When both sides are
closed, place the band in a small, smooth-jawed bench vice. Close the jaws
slowly to even out the closed end flaps.
Fitting the Band
A properly fitted expansion band should have no gaps between the links when
placed on the wrist. If there's a gap, add a link. (Or recommend buying
a larger size.) Otherwise the band will bind the wrist, pull hair and be
When sizing, hold the band around the customer's wrist (see below) and
count the number of links that "bunch up." Subtract two from this
number and remove the remaining links using the procedure outlined above.
Open the band, count out the links for removal, slide them out and rejoin
the two halves.
After a few years of use, expansion bands begin to weaken and gaps appear
between the links. Dirt and perspiration aggravate this deterioration. When
an older band becomes uncomfortable, you can extend its life for a year
or so by removing several links. Afterward, the links usually become so
weak that replacement is the best answer.
||To size a band, wrap it around the wrist, count the extra
links and subtract two.|
David Christianson is fourth-generation owner of Christianson Jewelry,
Kendallville, IN. In addition to serving as president of AWI, he's a certified
master watchmaker and a fellow of the British Horological Society. He discusses
watch repair for the sales staff in this column each month. Questions, suggestions
and comments can be sent toProfessional Jeweler,1500 Walnut
St., Suite 1200, Philadelphia, PA 19102, e-mail firstname.lastname@example.org.
Copyright © 1998 by Bond Communications.