Can I retune a reed by a semitone?

[Rosie C]

A question... supposing I had the 'F' bass reed from a 12-bass accordion, is it likely it could be tuned down to 'E', or is that too much of a change? Similarly, if I had a B♭ chord reed, could it be tuned up to a B? I'm just wondering, as after watching a video by @Squeezebox Of Delights about disabling the thirds in a 12-bass, I started thinking how when rebuilding I could re-jig the whole thing to have CGDAEB as the 6 rows by re-arranging the reeds and tuning a couple and be able to play all my folk tunes

 

[Ventura]

physically, if you have to take so much mass
off near the flex point, it may make the reed weaker

tuning higher you just take mass off near the tip,
which seems to me less risky.. plus deeper bass reeds
have weight added on the tip which gives you a lot
to safely work with without even touching the steel

 

[Henry D]

supposing I had the 'F' bass reed from a 12-bass accordion, is it likely it could be tuned down to 'E', or is that too much of a change?

Doing it by scratching at by the flex point as per normal woulc probably be a bridge too far.

You could, however, brush and scrape the last 3/8-1/2 inch of the reed and then solder a dab on the end. You could then easily file away at the dab (it'd probably be too heavy and so flat) and bring it up to pitch. Should last indefinitely. Careful not to heat the whole reed too much and lose the temper- but you should get by with a quick dab using a fairly high watt soldering gun. (the higher watt soldering gun will more quickly heat just where you want it- a lower watt model winds up heating the whole reed before you can melt the solder.)

I'll get hate mail (posts) for this but it has worked for me in a pinch. The bass reeds are large enough that you can generally get away with it.

 

[debra]

The safest way to lower a reed by quite a bit is by adding a small dab of solder near the tip. This works well for low notes and best for notes that already have (copper) weight added. Use plenty of flux to ensure a good bond between solder and reed.
To raise the frequency you file near the tip but you do risk to weaken the reed too much and the tip may eventually break while playing.
In all cases it is safest to just buy new reeds made for the correct frequency.

 

[Rosie C]

Thanks everyone!

 

[Squeezebox Of Delights]

A question... supposing I had the 'F' bass reed from a 12-bass accordion, is it likely it could be tuned down to 'E', or is that too much of a change? Similarly, if I had a B♭ chord reed, could it be tuned up to a B? I'm just wondering, as after watching a video by @Squeezebox Of Delights about disabling the thirds in a 12-bass, I started thinking how when rebuilding I could re-jig the whole thing to have CGDAEB as the 6 rows by re-arranging the reeds and tuning a couple and be able to play all my folk tunes

Funny you should mention that, because I've just 'reprogrammed' my kit-built Hohner to have thirdless chords, and shifting all the reeds along two places to give a bass range of F-F# so I can play English trad more easily. I'm still getting used to the shifted layout, and I'm missing my Bb a bit, but otherwise it seems like a positive change. Maybe at some point I'll move them back one step and go Bb-B. I guess I'll see how many tunes in B minor I end up playing!
You could definitely do something similar to a 12 bass but, because of the way it's set up inside, you'd possibly need to buy replacement reeds. If the only ones you need to retune are bass reeds you should be fine(either add a big chunk of material onto the end or remove some of the big chunk of material that's already there), but otherwise you'll want to get replacements. Luckily it'll be pretty easy to pick up an unrepairable box and salvage the reeds from it, particularly if you can make do with mediocre Dix reeds from an old Klingenthal box - I've used them to replace broken reeds in a Hohner and I honestly can't tell the difference!

 

[Rosie C]

It is just like 're-programming'! I was looking at a diagram of 12-bass reeds and just thinking how I could take them apart and re-arrange to my liking. I'll not miss the B♭ at all - I'm thinking of building this box just for Morris and B♭ isn't used in any of the tunes.

Getting a second accordion for parts is a good idea - that would give me a second B chord reed without having to re-tune a B♭. Then as others have suggested, just a dab of solder on an F bass reed to get the E.

 

[boxplayer4000]

I have a lot of 'spare' reeds.
You're welcome to some. I need to know their lengths/pitches/8, 16, 32 64ft.

 

[Rosie C]

I have a lot of 'spare' reeds.
You're welcome to some. I need to know their lengths/pitches/8, 16, 32 64ft.

Thank you!

 

[Rosie C]

I drew a picture

 

[SteveBox]

I drew a picture

What you have created is similar to half of the 24 bass Darwin open-chord system. The difference is that the Darwin has 12 additional buttons, allowing you to play chords and bass runs for all 12 keys. A few accordion builders are offering this on small diatonic and chromatic button accordions. It would work for a small PA as well, but I don't know if anyone has done this.