Concertina Issues to be investigated

Introduction

It doesn't take long to come up with a list of matters we'd like answers to.  Unfortunately, it will probably take longer to come up with the answers!

As any of these matters are investigated, links will appear to the relevant articles.

Concertina pressure and airflow tests

Test protocols

• Determine typical playing pressure

• Determine minimum operating pressure

• Determine standardised test pressure (e.g. 250mm, 10" water?)

• Other?

Test facilities

• design and build facilities to conduct tests below.

External leakage paths

• Devise ways to test leakage to outside the concertina through these paths:

  • through bellows

  • around bellows (i.e. through gasket seals)

  • through or around pads

  • other paths?

• Determine effect on leakage through leather when stretched

• Determine typical leakage values for above

• Determine threshold leakage values for above.

• Devise informal ways to test above, and correlate with formal tests.

• Correlate overall leakage rates with players' perceptions.

• Other?

Gasket leakage

• Investigate alternative materials for gasket applications, e.g. chamois, leather, closed cell foam, other?

• Relationship of clamping pressure to sealing ability

• Compare results of spring clamping and screw clamping to determine typical screw-clamping pressures employed.

• Capacity of various materials to accommodate irritants of varying thickness.  (Sorry about the pea, Princess, but we had to be sure...)

• Determine by how much does roughing up the surface of chamois improve the seal?

• Does gluing gasket material down reduce its ability to accommodate movement? Are there "better" glues?

• Does doping have anything to offer? Neatsfoot oil, Dubbin, silicone rubber, spray varnish, other?

• Consider methodologies for investigating Intra-chamber leakages

• Other?

Pads

•  for various pad materials and constructions:

  • Determine relationship between pad leakage and applied spring pressure

  • Determine influence of pad plate surface and surface treatments on leakage

  • Determine effects of imperfections in seating efficiency

  • Determine effects of non-parallel contact

  • Determine impact of non-central pressure

  • Determine relationship between pad leakage and the polarity and magnitude of applied air pressure

  • Consider other desirable and necessary properties of practical pads.  Correlate with tests to identify most likely to prove successful.

  • Other?

   

•  sampers, beads, straps

  • investigate purpose of and need for sampers and straps

  • investigate how sampers and straps meet these needs

  • determine desirable characteristics of sampers and straps

Reed characteristics

• Determine (for large, medium and small reeds):

• typical operating pressure and airflow

• minimum operating pressure and airflow

• maximum operating pressure and airflow

• reverse airflow (when used without valves)

• Other?

Valve (leather) characteristics

Determine (for an average size and typical material)

• minimum opening pressure

• minimum closing pressure

• closed airflow at playing and test pressures.

• effect of adding a Mylar spring

• effect of surface treatment to the reed pan timber

• other?

Sound

Determine effects on concertina tone and volume of:

• pad materials

• pad height when open

• chamber volume, length, width and depth

• chamber surfaces

• metal and wooden ends

• leathers

• others?

Other?

• Are there other areas of the concertina overlooked?
   

Conclusion

It's clear that we have plenty of questions to answer already, but, if there are matters bothering you, feel free to get in touch and we'll add them to the list.  And if you feel you already know the answers, don't just sit there, but let us all know!

Back to McGee-flutes Index page...

Created: 9 June 2014; Updated: 25 June 2014