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Discussions => Instrument Design, Construction and Repair => Topic started by: robotmay on May 16, 2018, 10:28:34 AM

Title: What's the difference between chromatic and diatonic reeds?
Post by: robotmay on May 16, 2018, 10:28:34 AM
Came across some mentions in old threads of there being a difference between chromatic box reeds when compared to diatonic ones. Is there a difference in the construction of the reeds, and if so, what are the effects that those differences have on how the reed responds? Does it prevent them from being tuned to diatonic setups? Do they just not work properly when subjected to the forces inside a diatonic instrument?

Mostly in relation to old Hohners, as I have an old PA for spares that might be useful, but I don't want to go through the hassle of refurbing some reeds if they're no use in a diatonic ;D
I've been working on learning to tune again, and I couldn't find much info on this, other than mentions of them being different!
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: GPS on May 16, 2018, 11:24:18 AM
AFAIK there's no structural difference. I've used a number of unisonoric reed pairs to retune to a bisonoric pair.  There's a limit to how far you can go, but a semitone either way is quite easily do-able and will therefore give you a pair a full tone apart.

Graham
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Theo on May 16, 2018, 11:38:37 AM
I’ve also used unisoniric reeds and tuned them differently for use as spares in a bisonoric box. One difference I’ve found is that Hohner piano box reeds often  have a longer scale length than those in Hohner diatonic boxes.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: GPS on May 16, 2018, 12:28:28 PM
Yes, I've also discovered that. As it happens I made a very cheap purchase on eBay some years ago of "assorted reeds & blocks" for a few quid. When they arrived I was amazed by how many there were - at least 40 reedblocks, some empty and some partly or fully loaded, and a box of a couple of hundred or more mainly "H" reeds, so I've so far been able to find reeds that have been about the right size!

Graham
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: robotmay on May 16, 2018, 05:16:54 PM
Awesome, thanks guys. I'll continue experimenting with what I can do with them! :D
I've only just heard about using solder to lower the pitch, so that's next on my list of techniques to try. Might need a better soldering iron, however.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: malcolmbebb on May 16, 2018, 05:38:58 PM
And a different file reserved for solder.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Rees on May 16, 2018, 05:45:52 PM
And a different file reserved for solder.

Absolutely.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: robotmay on May 16, 2018, 06:13:45 PM
Luckily I've just acquired another two small files, so I'll keep one separate for that :D

Also one extremely large (nearly 30cm long) file because I misread the size...
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Martin P on May 16, 2018, 07:15:19 PM
As a non-engineer, may I ask why the advice to reserve a different file for solder? Just curious.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Rees on May 16, 2018, 07:18:39 PM
As a non-engineer, may I ask why the advice to reserve a different file for solder? Just curious.

Solder clogs the teeth rendering the file useless for tuning hard steel reeds.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Lester on May 16, 2018, 07:21:06 PM
As a non-engineer, may I ask why the advice to reserve a different file for solder? Just curious.
Solder, being very soft, fills up the teeth of a file very quickly and, to all intents and purposes, makes it unusable for anything other than filing solder. After use on solder I usually heat the file over my camping stove and whip the solder out with a rag.

Bugger Rees beat me, I had to clear cookies AGAIN   >:(
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Theo on May 16, 2018, 08:04:47 PM
Emery boards sold for nail filing are good for filing solder,  cheap enough to discard when they get clogged.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: RogerT on May 17, 2018, 05:56:18 AM
I find that a dab of flux on the end of the reed works wonders when applying a blob of solder. Otherwise you'll spend a few minutes chasing the blob until it decides to (finally) cling to the tongue.
I use a steel wire brush to unclog files but don’t use the same ones used for tuning. Filing brass also clogs the file.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: malcolmbebb on May 17, 2018, 08:37:08 AM
I have a lifetime supply of "old-fashioned" leaded electrical/electronic solder with integral flux. It is easy to use on reeds.
(I have yet to try unleaded but I struggle to get it to stick even where its supposed to go. )
The flux cleans off with alcohol.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Tone Dumb Greg on May 17, 2018, 08:43:53 AM
Does flux have an ongoing corrosive effect?
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: malcolmbebb on May 17, 2018, 08:58:02 AM
Flux used for plumbing and other hard soldering is, I believe, acid based and needs to be removed. Not something I'd expect to see around reeds, though.
Flux used for leaded soldering is rosin based, and isn't always removed from electrical or electronic work so I as far as I know doesn't.
But flux deposits can come loose which would affect tuning so best removed.

Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Lester on May 17, 2018, 09:38:52 AM
But flux deposits can come loose which would affect tuning so best removed.

The important bit but I would have written

But flux deposits will come loose which will affect tuning so must removed.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: triskel on May 17, 2018, 11:41:14 AM
Luckily I've just acquired another two small files, so I'll keep one separate for that :D[quote

I'd suggest you'd be better off using an old file on solder, and not waste a new one on it because it'll be good for nothing else afterwards.

Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Steve Coombes on May 17, 2018, 11:47:40 AM
(I have yet to try unleaded but I struggle to get it to stick even where its supposed to go. )


Hi Malcolm
I'd stick to the leaded solder if I were you. Lead free has a higher melting point ought to be used with higher power iron looks granular when soldered seems to ball more readily and is prone to crack when subjected to stress.
Steve
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Rob2Hook on May 20, 2018, 03:44:08 PM
I wonder what the corrosion resistance of unleaded solder is like?  It is common on boats (well, not common enough) to use tinned wiring, i.e. each strand of the wire is separately tinned before the wire is made up.  This prevents the copper of the wire from being corroded in a salt laden atmosphere.

I tried to make some changes to the wiring of my guitar and found that it had unleaded solder joints.  By the time I got the solder to melt the pot casing was nearly red hot and I ended up buying new components rather than risk the old ones failing.  Yes, I rewired using leaded solder.

I've always found it almost too easy to get resin cored solder to stick to steel, but it does require really good cleaning of the surface to get it to stick at all.  Bearing in mind you're adding weight it shouldn't be a problem to clean the area with a rub over with a kitchen scourer and a wipe with solvent.

It took me back to my "engineering" days all this talk about clogging files.  It was more common where I worked to rub chalk into a file to reduce the cut - the management were to tight to let us buy fine files!

Rob.
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: robotmay on May 20, 2018, 04:42:20 PM
It took me back to my "engineering" days all this talk about clogging files.  It was more common where I worked to rub chalk into a file to reduce the cut - the management were to tight to let us buy fine files!

Haha that's some impressive penny-pinching!

On the subject of soldering; anyone got a photo of an example of doing it well on the reeds? I've got some assumptions about where not to put it and possible side-effects (like stressing the reeds too much if the solder is too heavy/only in one specific spot), but I dunno if I'm right  ;D
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: syale on May 20, 2018, 07:40:33 PM
Rather than use a wire brush to clean files you can use a file card, made for the purpose of cleaning files. (wires tend to be thicker on wire brush than file card).

Stephen
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Lester on May 20, 2018, 08:14:27 PM
On the subject of soldering; anyone got a photo of an example of doing it well on the reeds? I've got some assumptions about where not to put it and possible side-effects (like stressing the reeds too much if the solder is too heavy/only in one specific spot), but I dunno if I'm right  ;D

Doing some on Tuesday, will try to remember to take photos
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: robotmay on May 20, 2018, 08:50:05 PM
On the subject of soldering; anyone got a photo of an example of doing it well on the reeds? I've got some assumptions about where not to put it and possible side-effects (like stressing the reeds too much if the solder is too heavy/only in one specific spot), but I dunno if I'm right  ;D

Doing some on Tuesday, will try to remember to take photos

Awesome, thanks Lester!
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Lester on May 21, 2018, 12:56:57 PM
On the subject of soldering; anyone got a photo of an example of doing it well on the reeds? I've got some assumptions about where not to put it and possible side-effects (like stressing the reeds too much if the solder is too heavy/only in one specific spot), but I dunno if I'm right  ;D

Doing some on Tuesday, will try to remember to take photos

Awesome, thanks Lester!

Better still a video (https://youtu.be/zlcpdifdFZA)
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: robotmay on May 21, 2018, 03:26:16 PM
That's great, thanks very much! Now to find where I hid my soldering iron ::)
Title: Re: What's the difference between chromatic and diatonic reeds?
Post by: Steve_freereeder on May 21, 2018, 03:38:56 PM
Better still a video (https://youtu.be/zlcpdifdFZA)

Brilliant! Very helpful. Thanks, Lester.  (:)  :|glug