Strap buttons

[BrokenBox]

Hello. Apart from slowly getting overwhelmed by the enormity of concertina restoration I have decided my next logical step is to put straps on the thing just to make handling it easier. "It" is a 48 button "budget" Rock Chidley, serial 3631 / 3634.  This brings me to two questions. Firstly, does anyone know whether Rock Chidley had holes or a slot in the strap for adjustment? Secondly, what on earth were the strap buttons made of? Picture attached.  I do not know if they are original but they look like some sort of fibreboard.  Are new ones available anywhere?  Cheers.

[Tiposx]

Those aren't the original setup. The buttons might be original (I doubt it though) but the screws are not.

Original thumbscrews were typically made of zinc or brass, with a threaded rod inserted into the centre and either brazed or shrunken in.

[BrokenBox]

Ah, thank you.  I've been trying to find pictures online and most of them show metal buttons except the attached photo  (zoomed in and cropped) which is also a budget RC (ref. C-244), in the concertina museum. It's not very clear but it looks grey with a knurled edge, which got me wondering.

[BrokenBox]

I found a clearer view of C-244's strap buttons and they do indeed look like brass with a knurled edge.  C-231 however looks just like mine (photo attached) and is also a budget model.  It also shows a slot in the strap, so although it is an earlier model (1285) I think that is the way I will go.  I'd love to know what they are made of though.
 

[wschruba]

If they're "plastic", it looks like a material common prior to Bakelite's development, made from pressed sawdust/using hemoglobulin (dried blood) as a binder.  The name escapes me at the moment (and google is useless searching for "composite doorknob material"), but it was a popular 'composite' material, especially found in cheap doorknobs, buttons, etc, from the Victorian era.  It has that same sort of dull, flakey look when it gets old. 

 

My turn-of-the-[last]century house has one left in the (now) attic space, complete with surface-mount lock.  Clearly meant for the help, so to speak.

 

If you are going to replace it, I would do as suggested above, and replace it with a brass or zinc one.  There are a few companies who are selling parts that can be retrofitted.

[Kevin Knippa]

The early "plastic" was called hemacite.

[Parker135]

Today I learned about hemacite.  Concertina.net never fails to impress.

[fred v]

They look like zinc. It will start flaking off just like that with age.

[d.elliott]

Having dealt with several Rock Chidley instruments I cannot, ever, remember seeing zinc used on a strap adjusting screw, nor on a Wheatstone, or a Lachenal. Brass or nickel, yes. Silver and gold plated, yes. Zinc anywhere on a traditionally built English made instrument, never. 

 

 

[BrokenBox]

Thanks for all the suggestions.  I've examined the buttons through a big lens (and tried to photograph them) and my conclusion is that they are original. One of the screws fits the curve of the hole in the button and the thread of the hole in the action box frame very well.  I suspect the screw head may originally have been moulded into the button.  Whether it is Hemacite I'm not sure. It looks like it could be based on compressed fibre but the date for the hemacite patent is 1877/1878 which seems a bit late for the concertina, which I'm guessing as pre-1860.
All other suggestions welcome.

[d.elliott]

Not original to the concertina, but perhaps the bits went together off something else? I don't think Hermacite would have been in use at the time Rock Chidley was manufacturing concertinas. The Childley factory closed around 1865. Reading around, it seems that Hermacite  did not get going until the 1880's

Edited April 15 by d.elliott

[Lappy]

some wacky ideas…..

1. Stack a couple of brass washers and screw them down with pan head brass screws.

2. Drill screw holes first and cut out star shaped “hold downs” from a sheet of thicker brass. This can be accomplished on a scroll saw or by using a jeweller’s saw.

3. Cut discs from a scrap of highly figured hardwood.

[BrokenBox]

10 hours ago, d.elliott said:

Not original to the concertina, but perhaps the bits went together off something else? I don't think Hermacite would have been in use at the time Rock Chidley was manufacturing concertinas. The Childley factory closed around 1865. Reading around, it seems that Hermacite  did not get going until the 1880's

Does it not seem too much of a coincidence that C-231 in the Concertina Museum, also a Rock Chidley, has the same strap button?  Either it was original or there was a later concertina repairer who used them as replacements on more than one instrument.  I doubt we'll ever know.  Which is annoying...

[Duncan Luddite]

A little off topic, but may I ask, @BrokenBox, what the fretwork looks like? I have a Jabez Austin 32 button EC and the fretwork is identical to C-231, and a couple of the others. Mine was made in the mid. 1850's, so that might help with rough dating.

[Myrtle's cook]

I have a Joseph Scates amboyna 48 button EC, c.1851 based on label, with the same fretwork pattern. I think it is now generally accepted that different components may have been made as piece work by specialists then ordered/assembled by 'makers'. In this case the paper template for this pattern could quite easily have circulated between woodworkers, fret cutters.

 

Going back to topic I have never seen the type of strap button that initiated this thread. My guess is that the original ceased to work effectively. Perhaps the thread of the button - or thread of the hole that accepted it - became fouled/damaged, perhaps through overtightening, and this is the rather crude solution to achieve a solid clamping of the thumb strap.

[BrokenBox]

My concertina (photo shows end repaired but not yet re-finished) has the same fretwork as C-244.  I think yours, @Duncan Luddite, is actually the same as C-230.  C-231 has very simple drilled fretwork.  C-231, however, is the concertina with the same grey composite strap button as mine.  The hole in my action box frame is not damaged and the thread of the screw is a perfect fit for the hole. Additionally the shallow taper and blunt end of the screw suggests it is pre 1880, so I'm of the opinion the weird buttons are original.

Edited April 16 by BrokenBox

[Tiposx]

You just need to find a good supplier of haemoglobin now…..🤔

[BrokenBox]

Yes, I sweat blood over the fretwork; I wish I'd saved it now. 🤣