Finding Leaks

[Jon C.]

Hi,

So, I have this leak, it seems to be coming from the action board, the valves seem to be sealing. The notes sound seperatly, so there is no leaking between the chambers. New gasket chammy in the bellow frame, sealing the action board and the reed pan. There was a slight warp in the action board, but seems to be sealing to the reed board.

It is amazing that most of the reeds actually sound and are in tune with each other.

Any ideas?

Take care,

Jon

[Jon C.]

Hi,

So, I have this leak, it seems to be coming from the action board, the valves seem to be sealing. The notes sound seperatly, so there is no leaking between the chambers. New gasket chammy in the bellow frame, sealing the action board and the reed pan. There was a slight warp in the action board, but seems to be sealing to the reed board.

It is amazing that most of the reeds actually sound and are in tune with each other.

Any ideas?

Take care,

Jon

 

I found one leak in a corner, using a stick of incense, and looking for a upset in the smoke stream. still have a leak on the action board. I can see how the corners can be a weak point for leaks. I guess I have to look at the relationship of the gasket edge to the reed pan edge?

[d.elliott]

As a baby engineer I was sent to inspect some hydraulic gismo at the side of a 200Tonne electic arc furnace. One of the older hands wandered by and asked me what I was doing. 'Looking for leaks' said I. 'Then best try Wales' said he, and wandered off.

 

But can I suggest you eliminate all pad board orifices be means of: selotape? Tape over all the underside of pad holes, underside of any action pivot post holes, any screw holes from action plate pillar screws, even where pd board sits into the action caseing rebate. If that causes your leak to disappear, the its like Christmas, you keep unwrapping. Other than that Pad alignment is often an issue, coupled with a weak or badly aligned spring. If the leak is there on bellows compression but not bellows tension then its odds on to be a pad or spring causing a pad not to seal fully.

 

Dave

[Jon C.]

As a baby engineer I was sent to inspect some hydraulic gismo at the side of a 200Tonne electic arc furnace. One of the older hands wandered by and asked me what I was doing. 'Looking for leaks' said I. 'Then best try Wales' said he, and wandered off.

 

But can I suggest you eliminate all pad board orifices be means of: selotape? Tape over all the underside of pad holes, underside of any action pivot post holes, any screw holes from action plate pillar screws, even where pd board sits into the action caseing rebate. If that causes your leak to disappear, the its like Christmas, you keep unwrapping. Other than that Pad alignment is often an issue, coupled with a weak or badly aligned spring. If the leak is there on bellows compression but not bellows tension then its odds on to be a pad or spring causing a pad not to seal fully.

 

Dave

Hi,

That makes sense, I will try that. I bet it was in your book too, my bad.

I should have known, that is how I check my antique flutes...

Thanks,

Jon

[Jon C.]

As a baby engineer I was sent to inspect some hydraulic gismo at the side of a 200Tonne electic arc furnace. One of the older hands wandered by and asked me what I was doing. 'Looking for leaks' said I. 'Then best try Wales' said he, and wandered off.

 

But can I suggest you eliminate all pad board orifices be means of: selotape? Tape over all the underside of pad holes, underside of any action pivot post holes, any screw holes from action plate pillar screws, even where pd board sits into the action caseing rebate. If that causes your leak to disappear, the its like Christmas, you keep unwrapping. Other than that Pad alignment is often an issue, coupled with a weak or badly aligned spring. If the leak is there on bellows compression but not bellows tension then its odds on to be a pad or spring causing a pad not to seal fully.

 

Dave

I narrowed it down to the shrinking of the reed board. So I have built up the gap with a couple of pieces of card, (your recommendation on a previous post) and have replaced the chammy once again, giving the board a nice snug fit. Hopefully this will take care of the big leak. I am getting a little more "clar on the concept" as I go.

Thanks much!

Jon

[Dave Prebble]

Hi,

another handy tip is to get yourself a cheapo stethoscope - a couple of pounds on ebay.

 

Remove the drum from the end of the tube and replace this with a short length of small bore plastic tube ( I use a bit stripped from an electical cable).

 

This can then be inserted through the fretwork and can be used to check round all the pads etc. When the tip of the tube comes close to a leak you get a distinctive roaring sound. Not only can you identify which pad is leaking, but also which side of the pad.

 

Dave

[Jon C.]

Hi,

another handy tip is to get yourself a cheapo stethoscope - a couple of pounds on ebay.

 

Remove the drum from the end of the tube and replace this with a short length of small bore plastic tube ( I use a bit stripped from an electical cable).

 

This can then be inserted through the fretwork and can be used to check round all the pads etc. When the tip of the tube comes close to a leak you get a distinctive roaring sound. Not only can you identify which pad is leaking, but also which side of the pad.

 

Dave

That sounds like a great idea, thanks!

Jon