[Harp-L] Magic Dave beeswax sealing repost

[fjm <mktspot@xxxxxxxxxxxxxxxx>]

As promised the orignal post in it's entirety, fjm

Posted to Harp-L by

Dave Therault
Wed, 2 Dec 1998 15:50:31 EST

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The Best Marine Bands ...I've ever played. Ever.

Here's how:
The process is to use beeswax to seal the wood comb
and to replace reed plate nails with screws and
nuts. This very inexpensive and easy procedure
renders an instrument that plays like butter, is
completely leak-free, has a comb which will not
swell and shrink, but which feels like a natural
pear wood comb, has ideal compression, even
response, surprising timbrel accessibility, while
still retaining, and even enhancing the
idiosyncratic Marine Band performance feel and
sound. The waxed comb has a soft feel, similar to a
wet wood comb. It almost feels absorbent, although
it is completely waterproof. I believe that this
mouth feel, is due to the combination of the
softness of the wax, and the fact that
the wax has a tendency to allow the saliva to
surface evenly, for a very low-friction experience.
The waxed combs can be played immediately, unlike
other sealing methods which require long cure
times. If you mess up with the wax, you can just
redip the comb and quickly fix the comb surface.
The wax is non-toxic. You have a harp that can be
conveniently dissasembled. If the wax deteriorates
with age, it can be retreated with little effort.
I have built four of the these harps in different
keys and I find them truer to the Marine Band feel
than any harp I have played that is tweaked using
other methods. Three of them are the best harps
I've ever had. The fourth was an old bad harp to
begin with.
Cost? Negligable. Time? It takes me one hour and 15
minutes per harp.

{Disclaimer follows}


1 lb beeswax
1 small saucepan
utility razor
pen knife
080 X 3/8" or 7/16" screws, with nuts
sandpaper (grades 320, 400, 600)
true flat sanding table (inexpensive suggestion: 1
square foot polished marble tile)
small screw drivers (and/or nut drivers)
feeler guage
round toothpicks
popsicle stick or nail file
electric drill or dremel
1/16' drill bit
small fine file
needle nose pliers
punch
4-5 inch long rigid bar, true flat
clean, soft, lint-free cloth (I use my shirt
...clean enough)
1 Marine Band

Procedure:
1. Remove covers, and remove the two forward nails
in each cover. Replace covers.

2. Drill through the empty nail holes and
completely through the harp.

3. Remove covers and remove the remaining nails.
Replace covers and fasten with screws and nuts in
the two drilled out holes.
[A note on screws: Screws of a wider diameter than
080 are often used to fasten cover plates, for
example in the Special 20. I find 080 to be
sufficient for fastening the plates and the covers.
The length of 3/8" is ideal for fastening the
plates alone. Sometimes I am able to also use 3/8"
for fastening the covers over the plates, too. But
3/8" is sometimes too short for the covers and
thread won't bite, in which case I go to a 7/16"
length. I try the 3/8" because the 7/16" shaft
sticks out a bit past the nut.]

4. Drill through the two remaining empty nail
holes.

5. Remove covers.

6. Place a fresh piece of 320 grit sandpaper on the
sanding table. Sand the front of the harp, taking
material off the front edge of the reed plates,
being careful to apply even pressure, and checking
frequently for signs that the front edge of the
comb has begun to contact the sanding surface, and
beginning to remove the finish fron the comb.
Always be careful when in any way apply force
against the delicate partitions of the comb to
avoid breaking. (Broken partitions can be
reattached with epoxy to give a very strong joint.)
VERY IMPORTANT: Carefully watch not to remove too
much brass from the front edge of the plates,
compromising the channel that receives the cover.

7. Gently sand, in a fashion to create a bevel and
soften the now very sharp edge on each plate. Very
little sanding removes a lot material very quickly
at this step, so be very vigilant.

8. Place harp with draw reeds down on a surface
which can be drilled into.

9. Drill a hole through the harp at a point between
the second and third reeds at a point measuring
from the back of the plate that is even with the
nail that is between the fifth and sixth reeds.

10. Remove nail between fifth and sixth reeds. The
method I have used is to loosen the nail by
carefully sliding under the head with the utility
razor blade. Force the blade to the shaft of the
nail. This lifts the head a bit, without levering
(and risking breaking) the delicate blade. Slide
the pen knife blade under the head and lever it up
a bit. It may lift up comletely and easily. If not,
once you have enough lifted, hinish the removal by
pulling
with needle nose pliers.

11. Drill out the empty nail hole between the fifth
and sixth reeds.

12. Fasten with a screw in the now empty hole.
(This provides a little more integrity to the
placement of the plates while drilling. You may
wish to skip this step.)

13. Repeat steps 10 and 11 for the nail between the
eighth and ninth reeds.

14. Remove all remaining nails.

15. Sand front edge of comb on 320 grit paper, in
the same manner as in step 6, this time without the
plates. The partitions are especially vulnerable to
breaking at this point. Another reason to sand
lightly or moderately is to avoid putting deep
sanding marks on the wood. Watch to make sure that
you are holding the comb at a perfect 90 degree
angle to the table. Apply even pressure along the
whole length of the harp. Sand until almost all
traces of the factory finish are removed from the
front edge, making sure that the finish is coming
off evenly, adjustly pressure to accomplish this.
It is very important to be careful in this regard
and in the next sanding steps, to avoid changing
the shape of the comb or making uneven in any way.
It is very easy to mess up in sanding. Flat
surfaces, continually fresh sandpaper, good
support, and even pressure are critical.

16. Using a popsicle stick or nail file for
backing, use 600 grit paper to "break" or round the
front edges on the sides of the partitions. This
gentle beveling or rounding will make for more
comfortable sliding, especially for the tongue. It
is important to use 600 grit paper to avoid making
deep impressions in the wood, which the tongue will
find undesirable, and to avoid taking off too much
material. Be sure to support the partitions between
thumb and forefinger while applying the side torque
with the sandpaper. Don't want to snap one off now.

17. Lay the comb on its side on 320 paper. The comb
is very flexible in this position and it is very
easy for the pressure applied by a finger to create
a uneven removal of wood, which will surely result
in a bad comb/plate seal. Place a rigid flat bar on
the top to avoid this and ensure even pressure
during sanding. You may wish to light rub some
carbon paper on the side of the comb, which will
quickly reveal where all the high and low spots are
on the comb, sanding until all the carbon ink is
removed. I have not used this method, instead using
the removal of the mill marks in the wood as my
guage. Please note also, that because the comb has
more material in the solid area at the back and
less in the area of the partitions, and more
material where the partitions are smaller, it will
take some care to keep the sanding even.

18. Repeat step 17 on the other side of the comb.

19. Repeat steps 17 and 18 using the 400 grit
paper. Just a few strokes on fresh paper.

20. Repeat step 15 (lightly sanding the front edge
of the comb) with 400 paper. The goal in this step
is to gently remove any remnants of factory finish
from the front edge, and any marks from the 320
grit. As with any gradient sanding, the idea is to
remove as LITTLE wood as possible, just taking out
the marks from the previous grit, as it woud be
very easy to create an unacceptable tolerance
between the front edges of the comb and plates.

21. Repeat step 20 with the 600 paper. Gentle,
gentle.

22. Repeat steps 17 and 18 (sanding the sides) with
the 600 paper.

23. Repeat step 20 with no paper, polishing the
front edge of the comb on the smooth marble (make
sure the marble is clean so as to not mark the comb
with soil). You should notice the front edge taking
on a bit of a shine. This step is to make the
surface very smooth, and crush the open wood cells,
which would create and undesirable drag and
sensation on the tongue.

24. Since, some material has been removed, however
slight, from the thickness of the comb, now is a
good time to do a test assembly of the harp.
Assemble the harp with screws and check that the
plates are seating properly by looking through the
chambers toward a bright light. If you see light
coming through between plate and comb, it likely
means that the rivets on the draw plate are hitting
the comb. (You will usually find that the draw
plate is the problem.) If this is the case, using a
punch, lightly tap down the semi-circle-shaped
areas that have been pressed in to accept the
rivets from the draw plate on the underside of the
comb. This step is to deepen that receptacle so the
plate seats better. I use the flat head punch from
the Farrel Reed Knockout Kit. Be very careful, and
go slow, as it is easy to just chip this area right
off the comb. That may not be a disaster, unless
you compromise the general integrity of the comb.
It is also possible that the plates are not seating
if the comb is uneven from manufacture, or from
improper sanding, or if you have not removed all
the excess wax. Another possibility is that the
combs on used harps may be warped from exposure to
moisture during play.

25. Disassemble the harp and clean comb of dust,
using a cloth or air.

26. Heat the beeswax on warm-to-low heat. I just
put the block of wax into the pan, and use it to
stir the liquid wax as it is melting. I remove the
block after I have about 3/8 to 1/2 inch of wax
melted. Do not overheat. Wax will darken a bit.
Enjoy the honey-sweet smell!

27. Firmly, push 3 toothpicks into holes you have
drilled in the comb for the screws.

28. Lower the comb by the toothpicks into the
melted wax. Let the comb stay in the wax for about
30-45 seconds, stirring the comb around in the wax,
and not letting the comb lay against the bottom of
the pan, where contact with the burner could
overheat the wood. It is important to have the wax
at temperature that is not so hot as to be damaging
to the wood, and not so low as to not provide for
good absorption into the wood. This is something to
experiment with, and I suggest a very low stove
temperature.
CAUTION: Wax will burn the skin even at these low
temperatures.

29. Lift the comb out of the wax and hold it in a
position where the partitions are facing up,
letting the wax drip back into the pan as it dries.
One or more of the toothpicks may have a tendency
to fall out, so you'll be glad you have used three.


30. After the wood is cooled a bit and the wax is
solid and yellow where it has accumulated, repeat
step 28. You may wish to dip it a third time. I
have done so, and find that, air bubbles which come
out from the wood as the wax is penetrating, are,
with a third dip, finally minimized, likely
signifying a maximum wax penetration.

31. When wood is cooled again to the point that the
larger accumulations of wax are yellow, begin to
remove the excess, using the feeler gauge or some
other dull edged metal strip, to scrape the
surfaces down flat and smooth. Do this step will
the wax is still warm, and and workable. It's very
important to not leave any high or uneven areas of
wax, being sure to also remove wax from the sides
of the partitions. Be meticulous here. You are
preparing the joint between plate and comb. If you
have let the hot wax drip with the partitions
facing up, most of the excess wax will be at the
bottom of the comb and on the top edge of the
partitions, making the removal fairly easy. I do
not remove the wax from the top edge of the
partitions at this point. There shouldn't be any
significant accumulations in the channels between
the partitions, so it shouldn't be necessary to go
in there. Use a small tool to remove and excess
from the semi-circle-shaped areas that are milled
to accept the rivets from the draw plate on the
underside of the comb.

32. Check plates and use the file to remove any
burrs created in drilling. You may wish to clean up
the plates and covers if you are working an old
harp.

33. Assemble the harp.

34. Scrape the excess wax from the front edge of
the comb, taking care not to allow it get in the
channels. I use my finger nail for this as I can
tell just how much material I am removing and how
smooth the surface is becoming, and to avoid
scratching the surface with a metal tool.

35. Gently but rapidly polish the front edge with
the soft, lint-free cloth. The heat of light
friction softens the thin surface wax and smooths
out any irregularities.

You may wish to roll in the back edge of the
covers, a la Joe Filisko.
I've tested these harps by soaking them overnight
in water and there is no change in the comb.

- -Dave Therault




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"When Big Walter played, the blues fell all over you."
- --Sam Phillips