Designing A Modern "campaign Concertina" For Travel And Tropic

[jdms]

I see your example is an illustration from Wikipedia--if you look at the general Wikipedia for Bakelite (here), you'll see an illustration of several Bakelite samples in a number of colors. Bakelite jewelry was popular in the period before WWII--here's a short article with some illustrations.

[alex_holden]

Amazing what they managed to do with the translucent variety.

[MatthewVanitas]

Right, "bakelite" is a much broader term when I suppose I'm referring to a particular aesthetic often executed in Bakelite. What I had in mind is the kind of mottled "artificial amber" sort of look, or the tortoiseshell-like patterns. I wouldn't propose using actual bakelite since it can be brittle and also apparently doesn't do well in perpetually humid conditions, but I do like the look used in some of the appliances and jewelry from bakelite's heyday:

 

 

 

Just trying to find a plastic veneer that doesn't too much resemble a cheap accordion or a countertop; I'm confident we'll come across a solution with a little brainstorming.

 

 

So far as mold prevention, I'll ask some locals what they do, though I suspect the answer is probably "we wipe off the mold with a rag every time it pops up". One fellow who I speak to sometimes who might have some insight is Carey Parks, a fellow in Florida who makes PVC tinwhistles for tough environments. My three-part takedown whistle from him is holding up just great here, which it should since he made it for kayaking and hiking in Florida's coasts and swamps. He's big into backpacker stuff, so I'll drop him a line and see if he has any suggestions either for leather substitutes for bellows, and/or for treatments that would help keep the mold off leather. And/or at some point I can just ask around and find out what it is they put in bagpipe leather that's keeping my Swedish bagpipes mold-free!

 

I played the Swedish bagpipes for an audience at a pub here in Monrovia, mix of expats and local elites, and it went over really well. In the next few weeks I should be heading way up into the bush to supervise a bioenergy project, and looking forward to taking my sackpipa with me, and once it arrives in the mail in a month or so I'll bring my plastic-bodied Stagi Anglo. It'll give me something to muck with on slow days, and I imagine the local farmers will find the instruments pretty interesting. Though in fairness, probably most things I regularly do will seem unusual; this might also create an impression that playing Swedish bagpipe and concertina are very typical American pastimes....

[JimMacArthur]

I too think that old bakelite and actual tortoise shell represent gold standards to strive for. They have an organic presence and warmth that modern plastics keep missing. So if anyone finds any promising materials, please post. There's is a lot of interest in home-made micarta among textile and paper artists, so I bet that there are wonderful things out there that we haven't discovered. Then there's Kirinite:

 

http://kirinite.com/

 

http://mtknives.net/2014/07/kirinite-knife-handles/#post/0

 

which is a toughened acrylic with colored sheets of polymer swirled through the mix. I haven't used it yet, but I'm game to try. I work with acrylic all the time, and I detest it, but this seems different. I'm told that it's considerably softer and less inpact-resistant than real micarta, garolite, or other epoxy-based plastics, which isn't a good thing, but it would be easier on my tools.

[alex_holden]

OK, cool, that would be pretty nice. It looks a bit like artificial tortoiseshell. I'll see if I can track down something similar in vinyl.

[alex_holden]

Thanks Jim, the Kirinite sounds interesting. This looks like it might a possibility:

http://www.ebay.co.uk/itm/KIRINITE-Tortoise-Shell-1-8-1-5-x-6-Scales-for-WoodWorking-Knife-Making-/181880380540

[MatthewVanitas]

Talked it over some more, and current thought is to make the sides of the frame out of carbon fibre, then clearcoat it to prevent scuffing. With the aluminum ends it should make for a cool modern look. Digging into more metalwork ideas by googling up modern architects, and especially Gaudi has some good inspiration fodder.

 

If it doesn't throw off the plan too much, I have a slight modification to the notes to suggest based on my fiddling around with the Duettina app; confining myself to just 12 notes a side in finding that I almost never use the highest F#, so instead of 4-4-4 we could do 3-5-4 to get me a C# on each side:

 

C D E

F G A B C#

C D E F#

 

That makes the key of D an option in two octaves, and just sacrifices the highest note and one overlapping note.

[Don Taylor]

Carbon fibre and aluminium in a humid salt air environment:

 

https://www.corrosionpedia.com/2/1556/corrosion/galvanic-corrosion-of-metals-connected-to-carbon-fiber-reinforced-polymers

[Graham Collicutt]

There may be answers here: http://www.accordinas.com/index.php?lg=1&rbq=3 for moisture resistance.

 

What would 3 rows of 15 buttons give you with a Hayden/Wikki layout give you?

[alex_holden]

Carbon fibre and aluminium in a humid salt air environment:

 

https://www.corrosionpedia.com/2/1556/corrosion/galvanic-corrosion-of-metals-connected-to-carbon-fiber-reinforced-polymers

 

Thanks, I wasn't aware of this problem. Back to the drawing board again...

[MatthewVanitas]

So carbon fiber in direct contact with the aluminum ends would be prone to galvanic corrosion, but should it be fine to use a CF soundboard since it is secured to the plexiglass frame and not the metal ends?

 

 

Three rows of 5, Anglo style, would add slightly more range and chromaticity, though the downside is that you need 6 buttons per row to get the normal fully chromatic Hayden (rows of seven are nice for adding an enharmonic), so for me personally a 3x5 would be "neither fish nor fowl", adding some bulk but still not a full keyboard.

 

Mainly asking as a way to use the exact same body design for Anglo and Hayden, or some other angle?

 

Since the current thought is to make this with trad reeds, there's some incentive to stick to reed-economical layouts (within reason). That is, if I were wanting this same instrument in Anglo, I'd prefer a 24 to a 30 for reed costs, keeping size down, and because I don't need a ton of flexibility of key on an Anglo (I've mostly owned 20b Anglos).

Edited October 13, 2015 by MatthewVanitas

[Don Taylor]

I think that if you can properly electrically isolate the aluminium from the carbon fibre than you will have no problems with galvanic activity.

 

The trick is to be sure that they really are isolated - you cannot just put a stainless screw through a hole in the aluminium and thread the screw directly into the CF. Likewise, I am not sure if a felt pad between the aluminium and the CF would work in warm, salty, wet conditions.

 

This is all above my pay grade, I just wanted to warn you that aluminium really, really likes to sacrifice itself to a more noble material. I know a bit about it from its use as a mast material for sail boats. It is tricky stuff, but wonderfully light,stiff and strong.

 

Titanium would be OK with CF.

[alex_holden]

So it sounds like with anodising on the aluminium, lacquer on the CF, and some sort of plastic or rubber gasket between the two, we may still be OK. The instrument only has to cope with humidity and an occasional rain shower, not total submersion in seawater. We were planning to use titanium end screws anyway, plus they could be sleeved with a tube of something non-conductive like acetal where they pass through the soundboard (the nuts will be embedded in the acrylic bellows frames). I think using titanium for the end plates would probably be overkill!

 

This message brought to you with the assistance of a very purry cat head-butting my hands and drooling on the keyboard.

[Theo]

Yes Titanium might be overkill, but why not use stainless steel? It's also more durable than aluminium.

[alex_holden]

We talked about it among other options and Matt wasn't as keen on the weight and appearance of stainless. It's also considerably more difficult to machine. I'm planning to start with fairly thick plates, round over the corners of the top, and relieve most of the underside except where we need extra strength. A good aluminium alloy is pretty strong, and anodising will protect the surface.

 

An early idea that we moved away from was to start with 1" thick aluminium plates and hollow out most of the inside like a 'unibody' Macbook Pro.

[Pete Dunk]

You may find something of interest in two threads from melodeon.net started by Peter 'Stormy' Hyde on the subject of using (boat building) foam panels in instrument construction. I'm not sure why but some comments have been removed from the first one making it a bit slow to get started.

 

http://forum.melodeon.net/index.php/topic,342.msg2589.html#msg2589

http://forum.melodeon.net/index.php/topic,7117.msg88495.html#msg88495

[alex_holden]

Interesting, thanks Pete.

[Chris Ghent]

I have made ends from Titanium, it was not particularly difficult to machine. It is not forgiving; unlike brass or nickel silver you cannot ignore feed and speed recommendations and still get a good result.