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Weights On Reed Tips


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I might have just sent this to Geoffrey Crabb but thought others may have a something to contribute.

 

My concertina is relatively large (http://www.scraggy.net/~tina). This was done to extend the range of the instrument downward -- a very welcome feature, I might add. Mr. Crabb took one pair of reeds (that for F# just below the bottom line of the bass clef staff) and added material to the tip of the reed. The reeds sound two octaves below middle C. To my ear the quality of these reeds are matched to the others of the instrument in all ways. That is they have the same timbre, readiness to speak and dynamic range of the non-tipped reeds. There may be something I'm not hearing.

 

The left side of this instrument plays a fourth (fifth, by means of added keys) lower than a typical 55 key Triumph. It seems to me that Mr. Crabb could have added weights to the left side reed tips of a much smaller instrument and gotten the best of both worlds -- small and low on the left side.

 

Intuitively, I'm certain that this was considered, probably briefly, and for obvious reasons rejected. What were those reasons?

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It may be one of weight,the material added is lead and many people require lighter concertinas than heavier ones.It may be also that additional weight on the left hand would be unbalanced to that on the right.This is my theory.

Al

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It may be one of weight,the material added is lead and many people require lighter concertinas than heavier ones.It may be also that additional weight on the left hand would be unbalanced to that on the right.This is my theory.

Al

I don't know, but I would have thought that the fact taht the reed shoe would be shorter would more than compensate for the lead weight on the end of the reed, so I would supect that the weighted reeds would give a both a smaller and lighter instrument. As regards tone, the tendency to go flat when load etc. -- I really have no idea.

 

Clive.

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  • 2 weeks later...

I have recently re-tuned a 1923 Wheatstone Anglo using lead on the reed tips. I was very surprised as to how small the amount lead was require to lower the note. I would be surprised that the weight of the extra lead would be that noticeable, but then again if the reeds are especially large I could be mistaken.

 

Dave Green

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Concerning weighted or 'loaded' reeds and the possibility of a smaller instrument, if possible it is best practice due to various reasons not to load the reeds in a concertina but to use the appropriate correct sizes to attain the notes required. There are unavoidable exceptions*

Loading of reeds with a tin/lead alloy (solder) or brass generally works OK on large reeds (lower Baritone and Bass range) because the reed tongues are long enough for their flexibility not to be affected by the area loaded and as the loading is applied by heat, there is less possibility of the temper of the tongue being spoilt which is more likely with smaller reeds in the higher ranges. For reeds to be responsive, in double action concertinas, one requirement that is necessary is for their chambers to be as shallow as possible. A draw back with loaded reeds is that the chambers have to be made deeper to prevent the loaded tip touching the underside of the end (action) box when the note is playing at full volume i.e. the tip travel is at its greatest.

 

When considering the size of Kurt’s instrument, remembering that it was built by and initially for my fathers own use, there are some other factors to be taken into consideration. The number and size of the reeds on the treble or right-hand side would not allow a reduction in reed pan size and therefore the instrument size. The larger reed pan area adds to the timbre of the notes giving, in this case an organ like sound. The greater bellows area allows a more efficient flow of air through the reeds and a greater capacity for the larger reeds and sustained chord work. Reducing the size of the instrument would therefore require more folds in the bellows to compensate for this which could cause a handling/control problem if playing standing. The F# ‘s mentioned were loaded and voiced down to low/low C for my fathers own use and done this way so that the F# ’s could be restored easily if required on disposal of the instrument by replacement of the tongues.

 

*Exceptions.

Reeds in general should only be loaded if space is at a premium and the correct size reeds cannot be fitted. Examples of loading are seen often in Anglo concertinas where customer requirements have dictated the number of buttons (and hence reeds), or the range whilst being contained within a specified physical size of instrument.

 

Lower Baritone and Bass range reeds regardless of instrument type require a greater distance between the tip of the reed tongue and the pad hole for responsiveness and are generally loaded to reduce the overall size of the instrument.

 

The largest reeds in single action Bass & Double Bass concertinas in most cases, besides being loaded, are built into individual chambers which extend across the underside of the end (action) box, often above the smaller reeds. If this compromise is not done then the overall size of these instruments would render them unmanageable.

 

Geoff Crabb

Edited by Geoffrey Crabb
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Just a comment on using weights on the tips of smaller reeds. By using a heat sink on the tongues of reeds it IS possible to weight to the tips of even the smallest reeds without damage. Twelve years ago, I repitched a Crabb concertina from C/G tp D/A for Loretto Reid, not by moving the reeds around, but by adding VERY small amounts of lead to the tips of every reed. I used a heat sink to protect the temper of the reeds. Loretto uses her concertina a lot, and has appeared at major Celtic Festtivals across Canada, the US and Ireland. She is a professional performer. The instrument has stayed in tune to this day, and it plays extremely well. Any touch up tuning necessary would only be the normal amount needed by any good concertina for the amount of time and playing it has experienced. I also did the same procedure to the concertina of Warren Robinson to change his C/G Connor/Wheatstone to a Bb/F about six years ago. On the smaller reeds, so little additional weight is needed that it is almost impossible to detect it visually, as we are only talking a half step so it does not affect reed response.

However, it is NOT possible to add weights to the base of a reeds, because the heat would have to be added to the very part of the reed which needs to retain its temper. :)

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I don't know. The key to success , though, is to use a razor blade under the tongue for support, and a heat sink very close to the tip. The aluminum heat sink absorbs most of the heat and limits it to the tip end where it will not affect the lower portion of the reed. A friend recently retuned a Linota from old pitch using this method without filing away any of the original steel from the reeds. The thinking being that it could be reversed if desired.

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Frank,when you use a heat sink how are you getting adhesion of the lead on the steel? Is it that the underside of the reed is not heating up but the top is, sufficient to obtain adhesion? Is flux required or will lead adhere to steel without it?

Al

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Frank,when you use a heat sink how are you getting adhesion of the lead on the steel?

Just interpreting, and not really sure, but...

... I would think that placing the heat sink behind the tip of the reed allows the tip to heat up, but prevents draws the heat away from flowing further back. Thus the tip may in fact lose its temper, but that doesn't matter, because it doesn't really flex. Meanwhile, the rest of the reed keeps cool and thus its temper. (We sometimes abbreviate this as "keeps its cool". :) )

 

Is that right, Frank? Geoff?

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I have to make a correction to what I said earlier. The concertina I repitched for Loretto Reid from C/G to D/A was accomplished mostly by rearranging the reeds, only repitching reeds where I lacked the necessary reeds in my supply for reeds missing in the new scale. My error was because it's been quite a while since I did the work for her. However, I have repitched several concertinas to lower keys or from old pitch to A-440 (sorry, Paul) on the request of their owners, using this method.

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Some more bits......

 

My previous remarks in this thread were about loading reeds during initial construction. Any loading would have been made after sizing the tongues but before profiling (voicing) and installing in the reed frames. In general, in the Crabb workshop if loading was to be made to existing reeds for whatever reason, then new tongues would be made. The old tongues, if serviceable, would be salvaged and returned to the owner to be kept with the instrument for reinstallation if required at a future date.

 

As it was not our practice to retune by the application of loading the only comment I can make on this is that I do not see why it cannot be done and indeed some have but I would advise those contemplating this action to entrust the work to someone with experience.

 

The following is offered for consideration , others may have differing views.

When applying solder to the tips of cleaned reed tongues, a non-corrosive flux should be used and the heat applied should be just above the melting point of the solder used to obtain *secure adhesion.

The spring steel used in the Crabb workshop for most instruments from the early 1950’s till closure was tempered at about 300deg.C. therefore a solder with a much lower melting point than this was required. Pure lead has a melting point of about 325degC and if this was used then it is probable that part annealing of the steel tongue would occur.

A solder comprising of 33% lead and 67% tin has a melting point of 180deg.C, the lowest temperature for the combination of these two metals and is ideal. A perhaps more readily available mix now is known as 40/60 and this will have a melting point of 190deg.C which still should not affect the tongue if the heat is applied carefully.

An adjustable temperature controlled electric soldering iron is desirable and should only be applied for the minimum time to effect adhesion and apply the quantity of loading material required. It is important that the solder is attached to the upper side of the tongue only. Heat sinks can be used to shunt away excess heat. (I would be interested to see how these could be used on the smallest Crabb No 8 reeds [exposed tongue dimension 5/16 inch L x 3/32 inch W] when assembled).

 

*Great care must be taken in the cleaning, fluxing and heating of the area to be loaded to ensure that the solder has bonded with the tongue. It is easy for the solder to adhere solely by the flux if insufficient heat has been transferred to the tongue resulting in the solder becoming detached usually and embarrassingly in the middle of a solo public performance.

 

Although the reed tongue has been likened to a swinging door by some (Not in this thread), this is not the case. It is recommended that very small reeds are profiled so that they flex along there entire length. The application of solder to a portion of the tip will affect the available length of flexibility with possible eventual failure.

 

Geoff

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