Stuck bass reed

[Harry]

Hi. I was given an old "Goldwater Special" 120 bass by a friend last year. I am a beginner player. Lately, one of the bass notes (f) sounds at random times. Just the higher f reed and once it gets stuck it will continue to sound on all bellows movements, and intensities.

No buttons are sticking and to my untrained eye, all the mechanical bits look good (I've opened it up)

I think the only thing that could cause this problem is an open pallet (the felt things in the first picture... I am just learning about the mechanism). But they look fine to me.

And while I'm here.. some of the leather reed valves are bent away from the reed. Is this a problem?

Thanks..

 

[debra]

Hard to say what may cause the f to play by itself at random. The pallets appear to be fine, so the mechanism is the first suspect. You should take detailed pictures of the mechanism at a time when the problem occurs. When the random playing note is silent again nothing may be seen in the mechanism that is out of place...
The leathers that are curled up are a problem. They should all be straightened so they lay flat on the reed plate. If they are too stiff they should be replaced.

 

[JerryPH]

It is possible that when a value is open, it is going to let air in until pressure folds it flat and randomly sounds that note, so those raised valves could indeed be the issue. The purpose of those valves is to stop air coming in the opposite direction.

 

[Harry]

Thanks.. I'm pretty sure the mechanism from the buttons to the pallet is ok...But I'll have another look as suggested. Also another look at the pallet for that note.

I have no idea of how to straighten the valves. Replacing them does not seem too hard, is it?

 

[debra]

Thanks.. I'm pretty sure the mechanism from the buttons to the pallet is ok...But I'll have another look as suggested. Also another look at the pallet for that note.

I have no idea of how to straighten the valves. Replacing them does not seem too hard, is it?

If you suspect a pallet you should shine a light (flashlight) from the mechanism side up and see if light shines through around the edge of any pallet, and then also do the reverse: shine a light at the pallets and look in the mechanism part to see if any light gets through. (Dim the lights in the room for this experiment.)

 

[boxplayer4000]

Harry:
Have you made any progress in locating your mis-behaving bass reed?
It could be helpful if you can identify whether it is the fundamental F bass or a chord F which is causing the problem.
Though you say there’s no buttons sticking what you describe is a classic case of a button mechanism partially sticking and not allowing the pallet to close fully after being played.
Buttons tend to become sticky quite often because of dirt/grime/dust, misalignment of the buttons where they pass through their keyboard or where the piston rod, a continuation of the button, passes through its support at the rear.
If it’s a fundamental bass which is faulty there will only be two buttons to check but if its a chord fault then every chord button in the twelve keys available which use an F reed will need to be checked.

 

[Harry]

I think it is an issue with chord. It happened with a G7 chord, which has an F. Also Dm. I'll test another couple of chords that have f in them.

There are never any buttons that are visibly out of line when the f sticks. I'll figure out another few chords with an f that I can try. And some without. If this checks out, should I consider taking the whole bass mechanism apart for a proper cleaning. (This box I think is about as old as I am, which is old)

 

[boxplayer4000]

Harry;
I really would think twice about dismantling the whole mechanism. A lot of the potentially dirty areas can be accessed with a cotton bud without dismantling. Look on this site for advice about good cleaning solutions; it's been discussed before. WD40 is not recommended on this occasion. It leaves a greasy skin which attracts dust.

 

[debra]

I think it is an issue with chord. It happened with a G7 chord, which has an F. Also Dm. I'll test another couple of chords that have f in them.

There are never any buttons that are visibly out of line when the f sticks. I'll figure out another few chords with an f that I can try. And some without. If this checks out, should I consider taking the whole bass mechanism apart for a proper cleaning. (This box I think is about as old as I am, which is old)

Open up the bass compartment (remove the bass belt first). The first row of pistons you see is that of the 7th chords. Press the G7 and see if the piston is likely to jump past the lever it is supposed to push. A stuck bass occurs most often when a pin somewhere jumps past the lever. It can be a bit of a puzzle to figure out where it happens. Patience is key here!

 

[boxplayer4000]

The problem of the lever jumping out of place with the bass piston pin I associate more with an instrument which has suffered a fall or shock but it is a condition which can arise anytime and is fortunately fairly easy to spot and correct. Since Harry says he is a novice it might help to see the picture below which is what is seen when the bass cover is removed. The bass buttons are on the end of the vertical, white rods (pistons) just off the picture at the bottom. When a bass button is pressed the gold coloured lug on the piston engages with its lever (which in turn lifts the air palette etc). The ‘gold’ lugs should all be underneath their levers and the fault arises when a ‘gold’ lug ‘jumps’ past the lever and finishes up on the top side of the lever (and of course is no longer effective). It can often be re-located by simply pulling the piston rod aside to allow the lever to re-locate.

 

[Harry]

Thanks for all the advice. I'm going to have at it hammer and tongs tomorrow.

But much, much gentler : ) Q-tips and needle nose maybe.

I hope this turns out to be the issue cause it the easiest to fix.

I'm a beginner at this, but have a fair bit of mechanical experience, so I should be able to fix it if I can figure out what to fix and it not crazy advanced.

 

[boxplayer4000]

Go for it Harry.
What you've described makes me feel confident the obstruction/stickyness is a small matter. The only catch is trying to find it. Needle in a
haystack comes to mind.
Patience (and perhaps a small liquid stimulant nearby) should do the trick.

 

[Dingo40]

Speaking of needles in haystacks, check this out!

Missing radioactive capsule found in Australia

Emergency services "literally found the needle in the haystack", authorities have said.

www.bbc.com

 

[debra]

Speaking of needles in haystacks, check this out!

Missing radioactive capsule found in Australia

Emergency services "literally found the needle in the haystack", authorities have said.

www.bbc.com

Well... they did have "tools" to detect the radiation, which helped them find the capsuls.
To find problems with our bass mechanisms we only have our eyes and ears (and hands) to work with. So in fact finding a fault in the bass mechanism can be harder.

 

[boxplayer4000]

Australia's quite a big 'haystack'.

 

[Harry]

I've found something!

No buttons stick down, but on occasion some of these rods stay pressed down on some of the chords. I can feel a bit of rubbing somewhere if I push the rod by hand and can even get them to stick without using a button. I think that the button goes back in place because the lower rods in the chord are still pushing up.

Now what? I have to find the rubbie bit somehow in all of this forest.

 

[Tom]

When I have encountered this situation I have tried to locate the source and to judiciously bend a piece of the offending rubbing metal rod or post. This is a dangerous and potentially life threatening endeavor, which, when successful, results in one happy accordion player. I am quite sure I remember posting about this in the past, undoubtedly with pictures.

I recommend you bite the proverbial bullet and surge forward, throwing caution to the wind. If it doesn't work out you can always bend something else or take up flute instead.

Good luck, you can do it!

 

[debra]

I've found something!

No buttons stick down, but on occasion some of these rods stay pressed down on some of the chords. I can feel a bit of rubbing somewhere if I push the rod by hand and can even get them to stick without using a button. I think that the button goes back in place because the lower rods in the chord are still pushing up.

Now what? I have to find the rubbie bit somehow in all of this forest.

It is possible that one of the levers rubs agains a piston, not the piston of the button you are pressing. When you press the chord button three levers are pushed down, but when one (for F) rubs against a piston it may not come up or not come fully up when you release the button.
So you need to identify the catorcetto (lever) for F and see of any of the levers on that catorcetto rub against one of the pistons.

 

[Harry]

I think I (we) did it!

At least it did not stick on a first test play.

I still have no idea exactly what was rubbing on what or what I did that fixed it. I started removing button rods from the assembly and wiggling one of the rods connected to the f bar up and down and bending the exposed rods gently left. After removing 10 I could feel it running smoothly like the rest of the bass mechanism. That seemed to be a good place to stop : )

Thanks for all the advice, and I won't be needing a flute, or a trip to Philadelphia.