Re: Embossing and other questions

["G." <gigs@xxxxxxxxxxxxxxx>]

<quote>
Date: Sat, 13 Sep 2003 07:49:49 -0500
From: "Howard Chandler" <chandler@xxxxxxxxx>
Subject: Embossing and other questions

Tinkering harpers,

What is embossing?  I've heard this term a few times on the web.  I get the
impression that it's a way of narrowing the gap betwen slot edge and reed.
Does this technique involve burnishing, or deforming the slot edge?  Perhaps
someone can please explain how this is done and what tools are needed?

Also, can someone suggest a source for small machine screws?

Oh, one last thing.  The method of sealing Marine Band combs involves diping
them in hot melted beeswax?

I'm new here and so I apologize in advance if these are well worn topics.
I'm having trouble searching the Harp-l archives.


Thanks

Howard Chandler
</quote>

Hello Howard.

To your first question:
Bringing the reedslot edges in has had a number of terms assigned to it
including "embossing" and like you say "burnishing" is another.
Basically you take a round metal object and gently scrape it from the tip of the
reed slot to the near the base of the reed a couple of times to force the brass
edges in towards the reed.  The idea is to reduce the tolerance between the reed
and the reedslot edge.  You may end up with the reed getting caught on burrs so
it pays to have a 0.002 and/or 0.0015 feeler gauge on hand to run up the sides
of the reed to clear out the burrs.
I use the round top end of an E tuning fork, but you can use anything that is
cylinderical or round in shape and is as hard as brass or harder.

For Machine Screws I personally found 2M stainless steel with slotted head work
for me.  For imperial anything between 0-80 and 2-56 may be appropriate
depending on the instrument you are working on, 1-56 seems to be a good
compromise, and around 3-46 at 3/4" long should work as cover bolts.  I
recommend using Stainless steel screws as Pat pointed out to me they are less
likely to bind, and get some brass nuts just in case you end up stripping the
thread on the reedplate and for your cover screws.  I also like to make sure I
have two taps for every size screw I use and get a pin vise to hold it in when
you are tapping the reedplates or bits of brass to use as nuts.
You can source a great deal of materials and tools that are useful from
McMaster-Carr, they are a superb business. http://www.mcmaster.com/

Yes, the method of sealing marine band wood combs in beeswax involves dipping
them in hot melted beeswax.  I have an ugly large skin graft on my right hand
because of this very technique.  It is 18 months since I did it and it is still
healing and a daily cause of discomfort and annoyance, and it looks bloody
awful.
Wax has a flash point of around 85 degrees centigrade, or well under
the boiling point of water.  Once its alight if you try to move the container it
will provide the fire with more fuel, as in oxygen which will cause it to flare
up and spew out of the container.  It sticks to anything it touches and burning
fiercely, just like a wick.
Throwing water on it makes a great fireball which throws flaming wax to
everything within the radius of the fireball.  Do not throw water into a
container or puddle of burning liquid wax.  I know all this from first hand
experience.  Thankfully my flat wasn't too badly damaged and it was winter so I
was mostly covered in thick clothing which I managed to put out before it burnt
right through to my skin.  If it had been Summer I would've been burnt from
chest to foot and all of my right arm as well.     I was lucky that I got my
hand under cold water within a fraction of a second upon being covered in
burning wax or I would've lost both my index finger and thumb to it.  I am right
handed so I'm grateful for small mercies.  I have a very tolerant land lord and
most of the damage has been repaired or painted over now.
I strongly recommend avoiding this technique as it's potentially dangerous if
you are incautious as I was, and from my experience it does not work
successfully anyway, the comb swells regardless of the beeswax.
If your goal is to seal the wood from moisture to avoid swelling and warping
then you are better off to find a water based non-toxic polyurethane and apply 4
coats with appropriate drying time in between.  Make sure your first two coats
are applied very thinly otherwise the comb just soaks it in and swells and warps
anyway.
If you absolutely insist on using beeswax then use a double boiler, or at the
very least two pots, a bigger pot with water and a smaller pot floating in it
with the wax in that.  You can buy beeswax at wood supplies cheap, and at
healthfood supplies, its about US$1.50 a pound.  Use a controlled heat source
and keep it low.
Keep the lid to the boiler and a fire extinguisher on hand well within reach.
Stay watching it while heat is applied. Do it sober and alert.  And be bloody
careful.
If the melted wax fizzles or smokes in any way remove it from heat and put a lid
on it immediately, and keep a watch until you are sure its cool enough.
The technique I learnt was to warm the comb(s) in a preheated oven for 10
minutes or so to open up the pours.  Then immerse the combs in liquid wax for a
minute or so, lift out and give the holding utensil (be it plyers, chopsticks or
tongs) a rap or two against the side of the pot to shake off excess.  Then
thread a wire through one of the cover bolt holes and hang to dry.  Turn off the
head.
The customer I was doing this for insists that the beeswax gives the instrument
a wonderful tone, but then he believes wood gives the harmonica a warm tone so I
just gave him some blocks of wax with careful instructions and refuse to use wax
anymore.  I was a bloody idiot by not keeping watch over it, I've paid the price
and
learnt my lesson the hard way.

If you really want to learn the secrets to a great sounding harmonica that plays
well I suggest you concentrate on TUNING and REED ADJUSTMENT before worrying
about all the other tips and tricks that are passed around like gold nuggets.

Concentrate on the reeds.

Pat Missin has gone to lengths to provide a good practical source on tuning
called Altered States available for free on his site
http://www.patmissin.com/tunings/tunings.html

Key points are to learn to use your ears, get a hotcold pack for the most
efficient way of keeping the reedplates warm, use sanding wands, wet and dry 200
& 400 grit or nail emery boards for retuning.  0.008 steel feeler gauge is good
for supporting the reed while retuning.

Both Pat and Mike Easton both helped me produce a practical guide for beginners
on setting up harmonica reeds which you can read free here:
http://www.angelfire.com/music/harmonica/reedadjustment.html
Also Tinus is good at doing this for harmonicas intended for overblowing (I have
one of his MS MeisterKlasse harmonicas here) and he has an a well written
section on setting up your harmonica reeds (and reed slots) for this at one of
his sites:
http://www.tenhole.com

You can find articles on things like bringing the reedslot edges in, methods of
tuning, and other practical articles of information all for the taking here:
http://www.angelfire.com/music/harmonica/harptechtips.html

It is also useful to get a rotary tool with speed control, NOT for tuning. But
very useful for many other things, rubber bits or Shofu brownies are very useful
for quickly polishing down sharp edges on reedplates and covers, and working
away rust spots. Conical burrs for cleaning up around drilled holes and so on.
Dremel is a popular choice but I find it cumbersome for most harmonica work, so
if you can find a cheaper hobbiest rotary tool that has a way of accepting 3/32"
shank up to 1/8" shank, then you'll be able to use most of the Dremel tool bits.
Dentists have access to a huge range of appropriate bits for working on
harmonicas, it makes me jealous what they have at their fingertips.

Anyway, after that the rest is up to you, trial and error are your best
teachers, and there are plenty of good folk here who are happy to help.
There are a couple of books by Blackie Schackner such as 'Complete book of
chromtaic & diatonic "state of the art" repairs' available only at F&R Farrell
http://www.frfarrell.com  who have recently given their site a facelift and are
now contactable by email again after a year hiatus.  And Doug Tates "Make your
harmonica work better" which is focused on chromatic harmonica, but useful
nonetheless.   Neither are exaustive.  I have yet to see any commercial material
that is any better than either those books and what is available for free on the
internet put together.  And nothing beats personal experience.

The Yahoo archives are the pits and were a last resort, but it looks like a
better alternative is in the works.  http://www.harpamps.com/

Welcome to Harp-L.

Best regards
G.
http://harmonica.7p.com