Making Glass Topped Buttons

[alex_holden]

Have any modern makers tried to make glass-topped buttons? Real glass, not a clear plastic like Perspex.

 

I have been wondering whether it would be better to mould the glass pieces individually, or could you simply buy glass rod of an appropriate diameter, cut it to length, and wet grind/polish the top to shape. I've read that glass rods intended for lampwork are not made to very tight tolerances, plus they are only available in quite a limited range of diameters.

 

Would it be possible to get an undersized borosilicate rod, heat the end of it until it's sufficiently plastic, then push it into a metal mould to form the outer shape? If so could you get away with air cooling it afterwards or would it be necessary to anneal it?

 

The bottom part seems relatively easy to make in comparison: I would probably try turning and cross drilling a solid metal (maybe aluminium?) button base with a cup-shaped section on the top, and epoxy glue the glass piece into it. It might be necessary to make the action box slightly deeper than usual to ensure the top of the cup is below the underside of the end plate.

[Roger Hare]

Have you thought about asking at your local school/college? It used to be the case that some of the

laboratory technicians at such places had a little expertise in glass blowing (for laboratory glassware).

They might be able to advise.

 

I certainly learned a bit of glassblowing <mumble> years ago at Lanchester Polytechnic...

[wunks]

The image of extruding any number of them at once through a flat plate comes to mind.

[Geoff Wooff]

I  wonder why  Lachenal  used  glass buttons ?  

 

For:

 

Great  wear  quality.

Smooth  polished surfaces  glide  through  the  felt  bushings.

Clean  and  not  susceptible  to    attack  from   perspiration.

Can  be made in a variety of colours.

 

Against:

 

Heavy.

Need to  be  out sourced ?

 Expensive ?

 

At a time when Wheatstone's  were  turning over to  metal capped  wooden  buttons  which  were certainly  lighter than  the  Ivory or  Bone  buttons  previously used,  Lachenal's  made  light alloy  buttons with  silver caps  which  would  have a weight  similar to  those of  Glass.

 

Is  weight a  factor    in button choice.?.. Perhaps  not  in regard  to the  overall weight of a  concertina  but from  a point of  view  inertia, unsprung weight  etc.    

 

Noise  is  another factor. When everything is  perfect  there should be  little or  no  noise  from  a concertina keyboard  but  with  wear  and  lack of  servicing the  solid  metal  buttons ( and perhaps the glass  type  also)  can  produce  a variety of    annoying clicks.

 

[Stephen Chambers]

5 hours ago, Geoff Wooff said:

For:

 

Great  wear  quality.

Smooth  polished surfaces  glide  through  the  felt  bushings.

Clean  and  not  susceptible  to    attack  from   perspiration.

Can  be made in a variety of colours.

 

Non allergenic - to avoid nickel allergy? 

Edited March 11, 2020 by Stephen Chambers

[alex_holden]

6 minutes ago, Geoff Wooff said:

Great  wear  quality.

Smooth  polished surfaces  glide  through  the  felt  bushings.

Clean  and  not  susceptible  to    attack  from   perspiration.

Can  be made in a variety of colours.

 

Plus the clear/translucent appearance is cosmetically unusual and spectacular, something to set your top models apart from the cheaper models (similar to gold plated buttons).

 

7 minutes ago, Geoff Wooff said:

At a time when Wheatstone's  were  turning over to  metal capped  wooden  buttons  which  were certainly  lighter than  the  Ivory or  Bone  buttons  previously used,  Lachenal's  made  light alloy  buttons with  silver caps  which  would  have a weight  similar to  those of  Glass.

 

I do personally regard weight as a factor worth considering, but are glass topped buttons exceptionally heavy? I don't know. Assuming the same overall dimensions, certainly they will be heavier than wooden, bone or acetal buttons, but I'm not certain they will be a great deal heavier than buttons with an acetal core and nickel silver caps. They will be much lighter than solid nickel silver buttons because brass alloys are more than three times the density of glass. Glass has a similar density to aluminium, so a button with an aluminium base and glass top would probably be close to the weight of a solid aluminium button. I've worked on a Crabb instrument with aluminium buttons and they felt pretty light.

[alex_holden]

5 minutes ago, Stephen Chambers said:

Non allergenic - to avoid nickel allergy? 

 

Exactly, that was one of my thoughts too.

[Geoff Wooff]

Nickel alergy  .  Good  point  but  was that  a known  problem    in 1900  ?

 

I've been making  instruments  with  Nickel Silver  parts for more than  40 years  and have yet to  come across  someone  with  an  allergy  to  that metal.

 

 

Edited March 11, 2020 by Geoff Wooff

[alex_holden]

2 hours ago, Geoff Wooff said:

Nickel alergy  .  Good  point  but  was that  a known  problem    in 1900  ?

 

I've been making  instruments  with  Nickel Silver  parts for more than  40 years  and have yet to  come across  someone  with  an  allergy  to  that metal.

 

I don't know how early it was recognised. Supposedly something like 14.5% of Europeans have a nickel allergy, more so in older women (because it often develops from long term exposure to nickel-containing jewellery). I've so far had one client who mentioned it is a problem for them.

[Don Taylor]

I have a Lachenal Excelsior EC with glass buttons.  I believe that it is from around 1890 (no. is 26818).

 

[Stephen Chambers]

4 hours ago, Geoff Wooff said:

Nickel alergy  .  Good  point  but  was that  a known  problem    in 1900  ?

 

In the 17th century, copper miners in Saxony began to experience irritation caused by a "dark red ore" - since the substance, which would later be called nickel, led to many ailments, they believed it to be protected by "goblins", and called it "Goblin's Copper".

 

Quote

I've been making  instruments  with  Nickel Silver  parts for more than  40 years  and have yet to  come across  someone  with  an  allergy  to  that metal.

 

I share my life with someone who is allergic to nickel (which lots of people are), and it's been spoken of here in the Corrosive Sweat Problem? thread.

[Stephen Chambers]

10 hours ago, alex_holden said:

I have been wondering whether it would be better to mould the glass pieces individually, or could you simply buy glass rod of an appropriate diameter, cut it to length, and wet grind/polish the top to shape.

 

Have you seen this? https://www.hilgenberg-gmbh.de/en/products/rods-fibers/

[Bill N]

To add to the date range, I have a Lachenal 48 button English #6915, which Dowright has dated c. 1860.  Others here have called it an "Inimitable"- besides the glass buttons it has rosewood ends with brass inlay at the corners and green, gold tooled bellows and straps.  The buttons are very similar to those shown above in Don's post, except that the brass ferrules aren't quite as robust. The button tops are flat, with a chamfered edge.  Paint or dye has been put in the bases of some buttons (red for C, black for sharps and flats), causing the colour to reflect up through the clear glass of the whole button.

Edited March 11, 2020 by Bill N
Added photos.

[Stephen Chambers]

26 minutes ago, Bill N said:

To add to the date range, I have a Lachenal 48 button English #6915, which Dowright has dated c. 1860.  Others here have called it an "Inimitable"- besides the glass buttons it has rosewood ends with brass inlay at the corners and green, gold tooled bellows and straps.  The buttons are very similar to those shown above in Don's post, except that the brass ferrules aren't quite as robust. The button tops are flat, with a chamfered edge.  Paint or dye has been put in the bases of some buttons (red for C, black for sharps and flats), causing the colour to reflect up through the clear glass of the whole button.

 

Lachenal & Co's. Price List, 1862 of English Patent Concertinas from The International Exhibition of 1862, Illustrated Catalogue of the Industrial Department, British Division, Vol. II, s.v. “Class XVI.—Musical Instruments”, p. 112, shows that treble models 6 to 9 were all available with glass studs.
 

On this list, yours would have been a No. 6, Bill.

[Don Taylor]

The bases of Bill's buttons look like they are made from wood (is that right Bill?).  Mine seem to be made from brass.

[alex_holden]

1 hour ago, Don Taylor said:

I have a Lachenal Excelsior EC with glass buttons.  I believe that it is from around 1890 (no. is 26818).

 

Interesting, it looks like the shapes of the button tops varies a lot, which might suggest they were hand ground from plain rod rather than cast/formed in a mould.

[alex_holden]

45 minutes ago, Bill N said:

To add to the date range, I have a Lachenal 48 button English #6915, which Dowright has dated c. 1860.  Others here have called it an "Inimitable"- besides the glass buttons it has rosewood ends with brass inlay at the corners and green, gold tooled bellows and straps.  The buttons are very similar to those shown above in Don's post, except that the brass ferrules aren't quite as robust. The button tops are flat, with a chamfered edge.  Paint or dye has been put in the bases of some buttons (red for C, black for sharps and flats), causing the colour to reflect up through the clear glass of the whole button.

 

It's interesting to see how they joined a wooden core to the glass rod using a split metal (brass?) tube. Painting the bottom of the glass is also a useful tip.

[alex_holden]

1 hour ago, Stephen Chambers said:

 

Have you seen this? https://www.hilgenberg-gmbh.de/en/products/rods-fibers/

 

Thanks.