Reed valve springs

[KiwiSqueezer]

I'm slowly digging deeper into a Paramount, by E E Busilacchio, dismantling, discovering faults, removing corrosion, and wondering why I'm still a sucker for this sort of project, when I'm old enough to know better...

All the reed valve leathers will have to be replaced. Any advice as to whether to stick with leather, or go for synthetic, or a mixture, (or what?), would be gratefully received. There are plastic helper springs on the outside of all the reed blocks in one bank of bass reeds, but no springs on the inner side. Is this normal? If it is, why the asymmetry? Are the outer leathers considered to be more likely to curl? The plastic springs seem feeble, and have failed to prevent valve curling. If they are to be replaced, how would one know what thickness of metal(?) spring to order?

 

[debra]

For large valves (any note below C4) you may want leather valves. Anything higher is easiest to do with synthetic (plastic) valves. If you want to use leather, with metel booster springs, there is a learning curve in choosing the right strength spring, putting it on, adjusting the tension... so better go for synthetic.
When an accordion has leather valves with booster springs on the outside of the reed block and leather valves without springs on the inside it often means that the manufacturer was trying to cut costs, but sometimes it means the outside valve was replaced during repair and the inside valve was left untouched. Generally, plastic booster springs are rubbish. They do not hold their strength over the years.

 

[KiwiSqueezer]

Thanks Paul. I'm new to accordions, so it's not safe to assume that I know anything about them... Can I therefore ask for clarification?

Q1. It seems that booster springs should be fitted to the inside and outside reeds, not just to outside reeds; correct?

Q2. Can I translate the 'learning curve' in choosing spring strength as 'trial and error'?

Q3. Is the purpose of booster springs just to prevent or delay leather valve curling, or have they another intended function (as opposed to unintended side-effect), perhaps to do with voicing or reed response?

Q3a. Am I correct in thinking that a too-weak spring won't disrupt the reed's performance, but also won't be much good at preventing leather valve curl, whereas a too-strong spring will affect reed response and possibly tuning?

Q4. How many more questions can I ask, before I'm considered a nuisance?

 

[Dingo40]

The genie in the lamp granted 3 wishes

 

[Ffingers]

The genie in the lamp granted 3 wishes

I need just one - that all my wishes come true, which includes wishing to reverse them as required

 

[debra]

Thanks Paul. I'm new to accordions, so it's not safe to assume that I know anything about them... Can I therefore ask for clarification?

Q1. It seems that booster springs should be fitted to the inside and outside reeds, not just to outside reeds; correct?

Correct.

Q2. Can I translate the 'learning curve' in choosing spring strength as 'trial and error'?

Better: a lot of trial and error. (But most of it can be avoided by using synthetic (plastic) valves.

Q3. Is the purpose of booster springs just to prevent or delay leather valve curling, or have they another intended function (as opposed to unintended side-effect), perhaps to do with voicing or reed response?

The function is to help the leather valve to close and stay closed when the reed isn't being played.
The strength of the spring (and the stiffness or flexibility of the leather) also contributes to how the frequency changes under changing volume but this is complicated and mostly has a noticeable effect when the spring is too strong.

Q3a. Am I correct in thinking that a too-weak spring won't disrupt the reed's performance, but also won't be much good at preventing leather valve curl, whereas a too-strong spring will affect reed response and possibly tuning?

Yes.

Q4. How many more questions can I ask, before I'm considered a nuisance?

Many. But it depends on what you do with the answers. If you just keep asking but never get around to try revalving reeds you might become a nuisance.