Reed slow to speak (or not at all)

[fatt_mazio]

My A3 has become either slow to speak only on the push, or not at all, feeling like I'm facing built up pressure, which is very frustrating during tunes. I've inspected the reed and valve, not seeing any apparent issue or debris. One thing I have noticed is that if I go quickly from pull to push (it's an English) that it starts just fine. Thoughts? Thanks, as always.

 

edit: something resolved and all appears good now! Not exactly sure what I did...

 

edit 2: back to being slow to respond. Wondering if the reed set is too low? After having swapped the reed, it's definitely following the reed itself, not the valve.

Edited April 1 by fatt_mazio

[Scott N]

I had a similar problem and solved it. Mild corosion and crud can accumulate in the clearance between the reed and the shoe at the root of the reed near where it's fastened to the shoe. I found an automotive 0.0015" thick steel feeler gauge in my tool box and slid it up and down in the gap cleaning out the crud. Now it speaks free and clear. The clearance is slightly less than the feeler gague so I worked it at anangle to not put any stress on the reed. You don't want to cause the reed to shift in the shoe.

[Clive Thorne]

A sheet of paper can also work, until it tears off in the gap!

[Scott N]

That's a good idea for a hair or bit of dust along the side of the reed but I find that it takes the metal edge of the feeler gage to clear the gap all the way to the root of the shoe slot.

[d.elliott]

The reed is stalling through excess air pressure acting on too narrower gap between the tip of the reed tongue and the upper surface of the reed frame, increase the gap slightly to relieve the air pressure and all will be well. It works when it's companion reed has been sounding because the reed tongue is partially exited by transmitted vibrations making it easier for the initial release of air through the reed assembly. Nothing to do with reed fouling.

[Scott N]

Interesting theory. My experience supports the idea that, to speak clearly, the reed needs to be clear of the shoe all of the way to the base of the slot. I've had a couple of reeds that were sounding choked and light wasn't shining through the slot near the base until I "flossed them" with my steel feeler gage. Then the the clearance was clearly visible and it sounded bright and clear. Bear in mind that these reeds are over 100 years old so some light corrosion is expected.

 

[Jillser Nic Amhlaoibh]

Deleted reply

Edited Thursday at 07:01 AM by Jillser Nic Amhlaoibh
will be offline for a few days an unable to reply back

[d.elliott]

19 hours ago, Scott N said:

Interesting theory. My experience supports the idea that, to speak clearly, the reed needs to be clear of the shoe all of the way to the base of the slot. I've had a couple of reeds that were sounding choked and light wasn't shining through the slot near the base until I "flossed them" with my steel feeler gage. Then the the clearance was clearly visible and it sounded bright and clear. Bear in mind that these reeds are over 100 years old so some light corrosion is expected.

 

 

More than just a theory! You do not need a gap (set) at the root of the reed, indeed it is impossible to get one.  You do need flank clearance all the way down both side of the reed. To avoid stalling (the original poster's issue) we are talking about gapping or reed set, the clearance at the free end end of the reed tongue between the tongue and the UPPER surface of the reed frame. As I stated above.

[Scott N]

I'm sorry if I wasn't clear on my description. In your words my flossing of the reed needs to happen "in the flank clearance all the way down the reed". And I found that a steel feeler gague is needed to do it near the clamp end of the flanks because it's thin and rigid enough to do the job.

[d.elliott]

If you use a feeler gauge to sort out flank contamination, you risk displacing the reed tongue laterally, and any pre-existing burr from tuning filing can be rolled - over aggravating the situation. Assuming that the flank clearance is choked with the products of corrosion and dirt rather than the reed tongue being off centre line, then I use a scalpel to scrape gently down each flank of the reed tongue to get to bright metal; and a worn 600 grit file to clear the inside of the reed frame's vent. Whilst cleaning the vent I pay particular attention to removing any white 'salt' build up in the vent and to cleaning the areas of brass close to the reed tongue. You should then be able to hold the reed to the light with the reed tongue pressed down gently, just entering the vent, and see clear fine light bands down both side of the tongue and at it's tip.

[Scott N]

I appreciate your detailed advice. Thank you David.

[RogerT]

You need a way to sound the reed and observe it so you can get the gap exactly right (as Dave says). I have a couple of rigs..one to sound individual reeds (some bellows with simple shoe to hold the reed)…and another foot operated rig where i put the reed pan upside down and sound the reeds. Or else it is trial and error. The other factor is compression. If you have poor compression that will hinder starting a reed..esp big ones. Fluff up the chamois on the chamber walls when you reassemble, make sure the screws are tight (don’t overdo that) and check the pad. But watching how the reed behaves and making adjustments to the gap with the block/pan out in the open is how i voice concertinas (and accordions) ..(and before anyone comments..I fine tune with the reed in the casing…)

[fatt_mazio]

Agreed with David and Roger above. After having tried cleaning out any debris, my guess is still that it's a reed set issue: too low, very likely. Under high compression, it can fail to sound entirely, though under lower can often sound fine, and any time there is a bellows reversal on the note, it has no issue.