While rebuilding vintage tuner
knobs is sometimes an option,
the knobs on this mid-’50s Gibson
must be completely replaced. |
Soaking the replacement knobs in
an acetone, water, and toner mixture
at intervals will give you more
control over the outcome. |
This custom soldering-gun tip
helps evenly distribute heat
around the tuner shaft and makes
installing the new knobs a breeze. |
Throughout the years, many instruments
have come across our bench in need of
tuner knob restoration. This month’s guitar
is a mid-’50s Gibson flattop that arrived
with all six tuner knobs missing and a small
amount of residue remaining on the tuner
shafts—a clear sign that the instrument’s
original plastic knobs had decomposed.
During the 1950s
and ’60s, Gibson
used Kluson tuners
almost exclusively.
There were
different marking
variations used
throughout the
years, but for the
most part, the
Kluson tuners’
overall appearance
remained
the same.
(Gibson did offer
Grover
tuners as
a special order
option beginning in 1959.) The style of tuners
we will be resurrecting on this guitar are
referred to as “3-on-a-plate” Kluson tuners.
Tuner Removal and Prep
The tuners were carefully removed from the
headstock while keeping an eye on the press-in
bushings, as they seem to find a way of
falling out at times. This is a good moment to
remind you to keep your bench top clean—you might need to crawl around with a fine-tooth
comb to retrieve one of these bushings.
With the tuners off, I modified my Angle Vise
by adding maple baseplates to the jaws, to
avoid compression damage once the string
posts were clamped in. Some 1/8"-thick maple
bridge plate stock (item no. 1121 online at
stewmac.com) works well for cutting out two
sections of 8" wide x 7/16" tall baseplates. You
can attach these to the jaws with double-stick
tape. With the string post clamped securely
into the vice, I positioned the knob shafts so I
had clear access to work on them.
Since the tuner knobs were already gone,
I was able to avoid the steps of using heat
and removing the knobs with pliers. All I
really needed to do was thoroughly clean
the tuner shaft with a bristle brush and razor
blade before installing the knobs. I really recommend
the file cleaning brush for this task
(Stew Mac item number 0825), as it provides
you with a lot of control. While cleaning, I
was careful not to go past the portion where
the knobs end, so the exposed section of
the shafts would look original and unaltered.
Aging the Knobs
Stewart MacDonald has a wide variety of vintage-style replacement knobs. Their 11/16"
x 9/16" oval plastic knobs are the perfect
replacement for deteriorating vintage tuner
knobs. For this project, I chose Stew Mac
item number 0113 in white, and aged the
knobs using my own mix to really help the
color tone and sheen match the guitar. The
instrument certainly didn’t look brand new,
so I detailed the knobs accordingly.
For the detailing
mix, I used 1
ounce of acetone
to 1 ounce of
water (an equal
part ratio) in an
E-Z Mix disposable
mixing cup.
The water dilutes
the strength
of the acetone
so that when
the knobs are
submerged, the
plastic will not react and simply liquefy. For the
vintage tint, I added 13 drops of red mahogany
and 14 drops of lemon yellow ColorTone liquid
stain to the 2 ounces of acetone and water. I
then put the six knobs into the mix for two sets
of 10 minutes, gently stirring with a popsicle
stick, and included five minutes of air drying
while gently burnishing in the toner with a lint-free
cloth in between.
Always remember to
be safe when working with chemicals by using
proper protection and ventilation.
By submerging the knobs in timed increments,
I was able to control the degrees of tint and
enhanced, aged-looking fingerprints I was
looking for. (If you peer very closely at a new,
untainted knob, you will see a variety of what
I call “fingerprints.” Those fingerprints can be
enhanced with this diluted form of acetone
while melting in the toner, giving the knobs that
real vintage look.) This idea originated from
the days when I saw my father restoring and
building concertinas and accordions. He would
soften the celluloid plastic so it could be bent
and shaped to the instrument’s wooden frame.
Installing the Knobs
After the knobs were ready, I used a Radio
Shack soldering gun on the 150-watt setting
to heat up the tuner knob shafts (Weller
soldering guns also work well for this procedure).
A standard soldering pen or iron will
work for this job as well, but you should use
a heat sink and a moist cloth to avoid damaging
the gears from excessive heat.
The key element
to using the gun
is a custom tip I
designed and made
for this specific job
out of 5/32" brass
rod. Both legs of
the inside surface of
the tip are beveled
at an 1/8" length so that the tip legs can slide
over the tuner shaft. The legs set themselves
and lock to the pre-radiused notch, completing
the connection. Heat is then evenly transferred
through the tuner shaft, and in seconds the
knob goes on like butter. Use some Tri-Flow to
lubricate the tuning gears and you’re done!
The following tools and supplies used in this
repair are available from Stewart McDonald:
- Guitar Tech screwdriver set
- Stew Mac steel Angle Vise
- Maple bridge plate stock, 4" x 8" x 1/8"
- Double-stick tape
- White vintage-style tuner knobs
- Red mahogany ColorTone Liquid Stain
- Lemon yellow ColorTone Liquid Stain
- Mixing cups
- Tri-Flow
That does it for this month’s restoration.
Until next time, keep those chisels sharp!
John Brown
John Brown, of Brown’s Guitar Factory, is the inventor
of the Fretted/Less bass. He owns and operates a full
guitar manufacturing and repair/restoration facility, which
is staffed by a team of talented luthiers. He is also the
designer of guitar-making/repair tools and accessories that
are used today by instrument builders throughout the world.
For details, visit
brownsguitarfactory.com or shoot a note
to
info@brownsguitarfactory.com.