Repadding a Boehm-System Flute
This was a series of two posts on the
Fipple flute forum message board. You can read the original thread
WARNING!!! THIS POST ISN'T SAFE!!! FOLLOW THESE
DIRECTIONS AT YOUR OWN RISK!!! I TAKE NO RESPONSIBILITY FOR ANY DAMAGE THAT
RESULTS FROM EITHER FOLLOWING THESE DIRECTIONS OR FAILING TO DO SO!!!
Several times I've had inquiries about how to repad a flute, or if I had any
advice for those considering it. I've always warned people sternly away from
trying it, and referred the more persistant to my favorite book on the subject,
Guide to the Flute and Piccolo" by
Burkart & Phelan.
I've finally decided to post my thoughts as a kind of mini-howto--I do recommend
that anyone interesting in trying this get the above book, and please don't try
this for the first time on a fine professional-grade flute!!!
Repadding a flute takes a lot of patience, manual dexterity, and a few tools. It
also takes listening to your gut feelings: if you feel that you're about to do
something wrong, stop! and don't do it.
That said, here goes:
First, you're gonna need a feeler guage; I use a strip of thin cellophane
wrapper (such as from a box of cough drops) glued to the end of a strip of cane
that is about 1/3 of a clarinet reed. You can also use a match stick,
toothpick...just about anything to glue the strip to. I like to be able to give
it a good tug without it coming loose, so I usually glue it, then wrap the glued
section with thread that is wet with glue just to give it some extra strength.
The easiest way and the way I recommend is to replace one pad at a time, then
adjust the key, and have that key good before I move on. I start with the trill
keys, then the C-natural key, and so forth on down the flute. The one exception
is that unless the flute has a split-E, the “G” key mechanism has two pads that
move as a unit and have no adjustment. These pads must be replaced and shimmed
together, which can actually be one of the most challenging parts of a repad.
The smallest pads (the trill keys and C key) are the easiest. I like to “float
them in” on melted shellac—you can also use various kinds of glue or wax for
this. With the key off the flute, remove the old pad, and clean out the pad cup
to remove any old adhesive or shellac. Wet the new pad lightly, and stick a pin
or needle in the side of the pad—this serves both to hold the pad so your
fingers don't get burned, and also will allow moisture to escape from the pad
during play so it doesn't balloon up. Heat the key cup gently over a clean cool
flame (bunsen burner is ok, I would avoid any but the coolest torches), and melt
some shellac into the cup. Before it hardens, use the pin to place the pad into
the pad cup and press it gently into place using a damp cloth so you don't get
Then you put the key back on the flute—this is a good time to apply some key oil
to the steel (the rod or axle the key turns on)--and carefully heat the key
again until the shellac melts, and gently press the key down on the flute so
that the pad “floats in” on the liquid shellac and gets a good seal. Once you're
satisfied you have a good seal, wet the pad again and either clamp or use a cork
block under the striker to hold the pad down firmly to its seat so that you get
a good seat. Allow to dry for a few minutes and you should be good to go. The
seating on these smaller pads rarely changes or requires any adjustment later.
As an interesting aside, it is also possible to use sheets of perfectly-faced
cork instead of pads on these smallest keys. You float them in on the shellac
the same way. They have the advantage that they last longer than pads and have a
very definite firm feel under the fingers during play. The disadvantage is that
they are more sensitive to moisture (cork swells when wet, of course), and they
also add a kind of percussive “thunk” to the sound of the flute when they close.
I personally prefer pads, but I've also done cork and it does work well. I have
seen entire piccolos padded only with cork and they played beautifully.
You may be lucky if doing this with a fine grade flute: if the keys have never
been bent—and don't get me started on the idiot repairmen that bend keys! it
makes me want to choke them—then usually once you get one pad shimmed in the
rest of the pads down the flute will be consistent and seat well with the exact
The process on the larger keys is to remove the mechanisms one at a time from
the flute (being careful to note how it all goes together—if it's an unfamiliar
flute, don't be afraid to make copious drawings), clean and oil the steels, and
one at a time replace and seat the pads.
The larger pads don't float in on shellac, instead they sit on paper shims to
place them at the right height to hit and seat easily. Try one full shim first,
put the key back on the flute and press down gently. Make a small mark with a
felt tip pin to mark which side of the pad faces the key arm, and replace the
washer and screw, and also the resonator if there is one—it'll be a white
plastic piece that fits over the screw. Check the key with the feeler guage at
12:00, 3:00, 6:00 and 9:00 o'clock. Ideally you'll feel the same amount of drag
and pressure at all compass points. If it hits hard in the back, it's sitting
too tall in the cup and you need to remove the shim. If it hits hard in front,
it's sitting too low in the cup and you need to add a shim. If it his hard on
one side or the other, you'll need to cut an arc of a shim, about 1/3 of the
shim, and place it under the side opposite the side that hits too hard—if it
hits hard on the left, shim on the right, etc. to raise that side of the pad.
You may need to sand on a shim to thin it down. You can also cut your own shims
If a pad hits hard in the back and there are no shims under it the pad itself is
too thick—you'll need to purchase thinner pads if that happens. Some people try
to shim them in anyway but I don't recommend it.
After you get the pad hitting pretty much evenly all the way around—and there is
a little bit of leeway but not much—then you lightly wet the surface of the pad,
and heat a pad slick or “pad iron”--just a smooth piece of clean metal will do,
and move it quickly over the surface of the wet pad to steam out the
wrinkles—just like ironing clothing to get the wrinkles out. Put the key back on
the flute one last time—this is the time to oil the steel, too—and press down
and hold for a few minutes to get your test seating. Note that you should also
place one small pin hole in the side of each pad—I usually place it under the
key arm—so that the pad won't balloon up from moisture.
As you go down the flute, you'll have to use the adjustment screws (if there are
any) or the adjustment stops (more likely on a high-end flute). Use your feeler
guage to check how hard pads that move together hit their seats. Ideally all
pads that close at once should hit with the same force. If there are screws then
you are lucky, as you just turn the screw to regulate the motion. If not, then
you glue small pieces of paper under the adjustment stops to regulate the key
motion, which is considered better but is considerably more time consuming (and
frustrating!). As I mentioned before, usually the G mechanism has to be done as
a unit—both pads at once—because there is no adjustment. This can be the hardest
thing in the entire repad.
When you are done with a complete mechanism, wet the pads lightly and clamp or
use cork blocks under the strikers to hold the pads firmly to their seats so
they get their permanent seating. The regulation of the mechanisms will usually
need to be checked and adjusted again after this seating.
That's it! After about 3 weeks of play, the pads may need to be reshimmed and
reseated...this is normal. After that they should be stable and not move any
And be really careful with the needle springs—they really hurt really bad when
they go under a fingernail or thumbnail! I can't count how many times I've done
Good luck—your first repad is usually scary as hell but you'll wind up with a
flute that plays wonderfully. A well-padded flute requires only the lightest
finger pressure to completely seal and will have a wonderfully strong, singing
tone as a result.
(2nd post starts here)
By the way, on those needle springs, be sure you
carefully lift them from their seats on the mechanism before you try to remove
any key mechanisms. Pay special attention to the springs around the inline G.
Sometimes one key mechanism must be removed first so that another may be
removed. Usually the left-hand mechanism must be removed to release the
right-hand keywork. Be extra careful when removing the right-hand mechanism, it
must be slid sideways and up through the needle springs to avoid breaking them.
I'm actually having strong second thoughts about having posted all this
publicly. Anybody wanting to try it please
buy a book and read it first, I recommend the Burkart and Phelan book but
there are others that are good as well, and please also have all your pads,
tools, and equipment in hand before you start. Also buy extra pads, you will
inevitably destroy the first several you try to install.
The tolerances on shimming those pads are in the hundredth of an inch
range...unless you are extremely patient and have good micromotor control of
your hands, you should probably not try any of this on a good flute.
When you've done it several times it's not really hard, but the first time
especially can be really intimidating. Flutes come apart into
lots of little pieces.
Also you shouldn't try to remove any pins or separate any pinned
mechanisms...without very specific tools and some experience using them, you'll
never work those pins back in.