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Pre -tuning reeds issues

Pierre

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Hi,
I’m looking for some help for a tuning issue.
I have removed all the reeds of the bass side of my accordion and cleaned all thoroughly without removing metal. (small brass bruch inside and very fine steelwool outside , cleaned with nafta)
Reeds were not rusty and slightly dirty (inside)
I made a test below for pre-tuning reeds and I was surprised to find the pitch at about 444hz while it was slightly below 442 in the accordion.
I am not confident in starting to file to get the 442 target on the test below and to have a pitch let’s say at about 440 when the reeds will be waxed and mounted back in the accordion.
Maybe it is normal that the pitch raises that much when reeds are cleaned (and voiced)?
Or maybe the test below gives wrong readings? (should have measured on the test below before cleaning!for comparaison.)

Would I set my target at 443hz to avoid over tuning?

Thanks ,

Pierre
 

debra

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The correct tuning of reeds can only be measured with the reeds waxed on reed blocks (at least 2 weeks ago) and the reed blocks in the accordion. It is quite normal for the reeds to have a pitch of 444Hz when you measure the reed along and for it to have a pitch of 442Hz once it's fully mounted inside the accordion. The frequency of a reed can easily go up or down 2Hz due to the effect of the resonance chamber in the reed block, the block mounted on the sound board, the leathers offering some resistance to the air flow and the pallets also offering a bit or resistance...
You should never tune reeds under any other circumstance than inside the accordion. You can do a rough approximation by measuring a reed inside the accordion, then taking out the reed block and putting it on a tuning table. If the reed was for instance 2 cents too high in the accordion and with the reed block on the tuning table the reed measures 5 cents too high then you can tune it so that it goes down to 3 cents too high... But this requires the reed block to be positioned exactly the same each time you remove it from the tuning table to do scratching/filing...
 

Pierre

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Hello Debra,
Thank for your help.
I’ll forget about pre-tuning reeds out of the blocks. Maybe just to check if some severe out of tune reeds problems are caused by badly voiced reeds?
Still I was wondering if cleaning the reads would rather raise the pitch than lower it?
 

debra

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Hello Debra,
Thank for your help.
I’ll forget about pre-tuning reeds out of the blocks. Maybe just to check if some severe out of tune reeds problems are caused by badly voiced reeds?
Still I was wondering if cleaning the reads would rather raise the pitch than lower it?
Cleaning reeds may have a minute effect on the tuning, but if you clean the whole surface equally (not the tip more than the base or vice versa) that should be very little, certainly not the 2 Hz difference you notice.
 

Pierre

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Hi Debra,
Thanks for the information. I am curious to see the differences with the blocks back in the accordion.
I found nice little brass brushes which fits nicely into the reed gap and permitting to reach te whole surface of the tongue. For the underside it works well (on the blued face) but for the bare steel (on the top) I suppose it is better to use iron wool as the brass leaves residue and is making the reeds yellowish. A metalworker once told me this was not ideal to use brass brushes on steel.

For the final cleaning I found cotton sticks (the ones used for cleaning the ears) dripped into naphta working very well. (Also for the sides of the gap)

Thanks also for pointing out that the freshly waxed reed blocks have to settle a few weeks before fine tuning. I suppose this is somewhat like when a piano is moved to another house it has to climatise about one month before tuning? (I am piano tuner and restorer)

Best regards,
Pierre
 

debra

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...

Thanks also for pointing out that the freshly waxed reed blocks have to settle a few weeks before fine tuning. I suppose this is somewhat like when a piano is moved to another house it has to climatise about one month before tuning? (I am piano tuner and restorer)

...
The fresh wax needs to harden. It's a bit like with glue: it may stick after a few minutes but it's often recommended to let it harden for 24 hour for full strength. Wax does not harden as fast as glue. When customers are in a hurry (they usually are) you can do tuning after a few days, but if you have the time it's better to wait longer (a week at least). This is not just when you rewax everything but also when you for instance need to take out one reed plate (to replace it, or to replace a leather, or to fix anything else). When you wax the reed plate back into place, again you have to wait for the wax to harden before you can do "final" tuning that will hold for a long time.
 

Pierre

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Is it eventually recommended not to play the accordion before the wax has hardened?
 

oldbayan

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The fresh wax needs to harden. It's a bit like with glue: it may stick after a few minutes but it's often recommended to let it harden for 24 hour for full strength. Wax does not harden as fast as glue. When customers are in a hurry (they usually are) you can do tuning after a few days, but if you have the time it's better to wait longer (a week at least). This is not just when you rewax everything but also when you for instance need to take out one reed plate (to replace it, or to replace a leather, or to fix anything else). When you wax the reed plate back into place, again you have to wait for the wax to harden before you can do "final" tuning that will hold for a long time.
This is where reed blocks mounted on leather come handy!
There is a very interesting video showing the dynamics of reed plates and reed blocks, it is in French though, but the visuals and graphics say it all.
 

Dingo40

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Oldbayan,
I'm sorry but, despite my best efforts , the voiceover was all Greek to me, even after a whole year of high school French!😄
Still, a very high class video: thanks for sharing!🙂👍
I see he uses a handy, portable set of readily available to all tuning bellows 🙂
 
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oldbayan

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O
Oldbayan,
I'm sorry but, despite my best efforts , the voiceover was all Greek to me, even after a whole year of high school French!😄
Still, a very high class video: thanks for sharing!🙂👍
I see he uses a handy, portable set of readily available to all tuning bellows 🙂
One of the points made is that the reed block does not transmit sound! That is what he shows with the tuning fork. Also, the material used for the reed blocks has no incidence on the volume of the sound. Can be wood, metal or plastic, no difference.

The sound comes from the reeds moving the air, and it is important that the reeds be well affixed to the reed block to avoid a loss of energy, in case the reed plate is loose and vibrates. Nails or screws can be used for that. The reed blocks should also be firmly attached to the accordion body to avoid vibration and loss of energy. Tie bars between reed blocks can be used to further minimize vibrations.

At the end, the video shows why we should not store an accordion on its feet! This may cause the bass valves to deform and lean away from the reed plates. It's better to store the accordion on its side, like if it is being played.
 
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Glug

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Thanks for the explanation, I got most of it with my basic french.
But I did miss the 'storing the accordion' bit at the end.
 

Dingo40

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Oldbayan,
Yes, thanks for the explanation 🙂👍
Very enlightening.
The information about the reed block not affecting the sound seems counterintuitive and contrary to to popular mythology, but facts are facts.🙂
Firm attachment of all the parts makes sense and the orientation of the accordion during storage is consistent with this advice of the forums resident experts.
Thanks again for sharing the video 🙂
 

Ventura

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while the material of the blocks may make no tonal difference
the shape/dimension of the individual chambers the reeds vibrate in certainly do...

so a well designed, well crafted reedblock made from machined hardwoods
will most certainly give better results than one of the "matchbook" style
commonplace reedblocks you find today used in the garden industry
of generic accordionmaking and "at home" reed waxing

Piano's transmit the energy through Hammers/Strings/Wood into Soundboards and THEN out...
inefficient designs result in less volume and sensitivity for the Artist

an accordion design that robs energy FROM the reeds is what we want to avoid
in engineering and crafting and fitting the components as there is no
equivalent to the soundboard in an accordion
 

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