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Valve Curling


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There are lots of reasons for valves curling though in your case, with only 1 valve curling and the rest in good shape after 10 years... AND if the adjacent pitch vavles are okay... it may be due to a less-than-ideal vavle to begin with. The lower the reed pitch and larger/longer the valve, the thicker and springier the valve needs to be.

 

The best ones are skived and hand-punched from the forechest section of specially treated hair sheep hide. That part has the right density for larger vavles. As you work your way around the sheep the hide gets thinner (okay for smaller valves). The back and especially the shoulder areas aren't suitable at all as being too thin and not very stretchy. The neck area has too many folds that make for "weak" areas (easy to crease) in valves.

 

Not many people go to this extreme but rather buy valves from a supplier. The higher quality (and more expensive) the valves, the more attention will have been taken to the areas - and grain direction - the various size valves are punched from.

 

If all the rest of your valves are in good shape, you probably had a very good set of valves and a very knowledgeable person choose and install them (even with a great set of valves there'll be some culls). I think that your wayward valve may have been one that slipped by the quality control and installer.

 

-- Rich --

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There are lots of reasons for valves curling though in your case, with only 1 valve curling and the rest in good shape after 10 years... AND if the adjacent pitch vavles are okay... it may be due to a less-than-ideal vavle to begin with. The lower the reed pitch and larger/longer the valve, the thicker and springier the valve needs to be.

 

The best ones are skived and hand-punched from the forechest section of specially treated hair sheep hide. That part has the right density for larger vavles. As you work your way around the sheep the hide gets thinner (okay for smaller valves). The back and especially the shoulder areas aren't suitable at all as being too thin and not very stretchy. The neck area has too many folds that make for "weak" areas (easy to crease) in valves.

 

Not many people go to this extreme but rather buy valves from a supplier. The higher quality (and more expensive) the valves, the more attention will have been taken to the areas - and grain direction - the various size valves are punched from.

 

If all the rest of your valves are in good shape, you probably had a very good set of valves and a very knowledgeable person choose and install them (even with a great set of valves there'll be some culls). I think that your wayward valve may have been one that slipped by the quality control and installer.

 

-- Rich --

 

 

Steve Dickinson at Wheatstone did the valve work. I still wonder what actually makes the valve curl. It seems to me that it would have to be shrinkage of the hair side of the leather. This makes me wonder if there isn't something you could put on it to relax the fibers like lanolin which is the natural oil in sheep leather.

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Steve Dickinson at Wheatstone did the valve work.
And he's one of the best.
I still wonder what actually makes the valve curl. It seems to me that it would have to be shrinkage of the hair side of the leather.
Valves are usually installed with the split (hairy) side *down* against the reedpan. I can't imagine Steve installing one backwards. Vavles tend to curl toward the "skin" side rather than split side (one of the reasons their installed split side down).
This makes me wonder if there isn't something you could put on it to relax the fibers like lanolin which is the natural oil in sheep leather.
I recommend NOT oiling the valve. Just replace it. Oil may attract dust and/or make it adhere somewhat to the reedpan. Perhaps that is one of the reasons why hair sheep is used for valves - hair sheep have far less oil (grease/fat/lanolin) than do wool sheep.

 

-- Rich --

Edited by Richard Morse
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... hair sheep have far less oil (grease/fat/lanolin) than do wood sheep.

Did you mean "wool" sheep? ;) A friend of mine does have a few sheep that have escaped into the wood, but that's not what they're supposed to be known for, and when she catches them they're gonna become sausage. :o

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I am pretty sure he meant hair sheep, i.e. breeds of sheep that have hair instead of the traditional wool. For instance, I know that some are raised in the southwest US where the heavy wool could cause the animal to overheat. And yes, I know that certain tribes do keep wool sheep their as well.

 

Alan

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How much wool would a wool sheep shed in a woodshed shorn by wood sheep?

 

Saying that quickly 10xs will curl anyone's valves!

 

Part of the tuning and setting up process in reconditioning an instrument is checking all the valves for noiseless closure and response. Sometimes otherwise good looking valves "act naughty". Rehabilitation is really not practical and at $.50 apiece, replacement isn't cost prohibitive.

 

If you are a careful, deliberate person you can change an annoying popping or gurgling valve. I'd recommend reading the Dave Elliott repair manual. Avoid using PVA (white glue) that might "bring wood" with it the next valve change. Evaporated shellac a la The Button Box method is my fixative of choice.

There are threads in the repair forum that mention success with arabic gum as a gentle valve glue.

http://www.concertina.net/forums/index.php?showtopic=506

 

There is a possibility that the pitch of the valve affected reed may change.

http://www.concertina.net/forums/index.php...=1706&st=15

It may not be enough to bother you too much. But wholesale, do it yourself changing of all the valves is not recommended unless you are prepared for a retuning. And that is a job for an experienced professional.

 

Greg

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How much wool would a wool sheep shed in a woodshed shorn by wood sheep?

 

Saying that quickly 10xs will curl anyone's valves!

 

Part of the tuning and setting up process in reconditioning an instrument is checking all the valves for noiseless closure and response. Sometimes otherwise good looking valves "act naughty". Rehabilitation is really not practical and at $.50 apiece, replacement isn't cost prohibitive.

 

If you are a careful, deliberate person you can change an annoying popping or gurgling valve. I'd recommend reading the Dave Elliott repair manual. Avoid using PVA (white glue) that might "bring wood" with it the next valve change. Evaporated shellac a la The Button Box method is my fixative of choice.

There are threads in the repair forum that mention success with arabic gum as a gentle valve glue.

http://www.concertina.net/forums/index.php?showtopic=506

 

There is a possibility that the pitch of the valve affected reed may change.

http://www.concertina.net/forums/index.php...=1706&st=15

It may not be enough to bother you too much. But wholesale, do it yourself changing of all the valves is not recommended unless you are prepared for a retuning. And that is a job for an experienced professional.

 

Greg

 

I recommend gum arabic for valve work, it is in my book as that (second edition). This is one of the corrections from the first editition.

 

Dave

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Oil may attract dust and/or make it adhere somewhat to the reedpan. Perhaps that is one of the reasons why hair sheep is used for valves - hair sheep have far less oil (grease/fat/lanolin) than do wool sheep.

Rich, a friend has recently been raising my awareness of different "wool" sheep breeds, but until reading your posts in this thread, I hadn't realized that there were also "hair" sheep.

 

The Wensleydale breed ( post-13-1170693876_thumb.jpg ) is at the opposite extreme from hair sheep. :)

 

But I've now found this link to descriptions (with photos) of different hair sheep breeds, and it leads me to wonder whether specific breeds are better than others for valves (or for other concertina uses, for that matter). Do you get that specific?

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Steve Dickinson at Wheatstone did the valve work.
And he's one of the best.
I still wonder what actually makes the valve curl. It seems to me that it would have to be shrinkage of the hair side of the leather.
Valves are usually installed with the split (hairy) side *down* against the reedpan. I can't imagine Steve installing one backwards. Vavles tend to curl toward the "skin" side rather than split side (one of the reasons their installed split side down).
This makes me wonder if there isn't something you could put on it to relax the fibers like lanolin which is the natural oil in sheep leather.
I recommend NOT oiling the valve. Just replace it. Oil may attract dust and/or make it adhere somewhat to the reedpan. Perhaps that is one of the reasons why hair sheep is used for valves - hair sheep have far less oil (grease/fat/lanolin) than do wool sheep.

 

-- Rich --

 

I think we are using the term 'hairy side' differently, or else I am totally confused as to which side of the valve shoud be against the reed pan. I was using the term 'hair side' to mean the side of the leather that the hair grew on which is actually the smooth surface of the leather. I think you were using the term 'hairy' to mean the rough or split side. Is this correct?

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I think we are using the term 'hairy side' differently, or else I am totally confused as to which side of the valve shoud be against the reed pan. I was using the term 'hair side' to mean the side of the leather that the hair grew on which is actually the smooth surface of the leather. I think you were using the term 'hairy' to mean the rough or split side. Is this correct?

 

 

Michael

 

shiny (hard) side up, and the matt, (hairy) side against the reed pan & its vent

 

Dave

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I think we are using the term 'hairy side' differently, or else I am totally confused as to which side of the valve shoud be against the reed pan. I was using the term 'hair side' to mean the side of the leather that the hair grew on which is actually the smooth surface of the leather. I think you were using the term 'hairy' to mean the rough or split side. Is this correct?
Ah yes, you are correct. We get so many customers referring to the split side as the "hairy" side that we've been calling it that too so as not to confuse them. I'm going to have to be more careful about the "hair" and "hairy" side descriptions.

 

Not to confuse things, but there are animals which have hair that goes COMPLETELY THROUGH the hide! Now which side is the hairy one? Such as pigs. That's why pigskin is "breathable" - because once the hair is removed there are zillions of air passages from one side to the other.

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We get so many customers referring to the split side as the "hairy" side that we've been calling it that too so as not to confuse them. I'm going to have to be more careful about the "hair" and "hairy" side descriptions.

??? "Fuzzy", yes. But "hairy", no. ("Nappy" should be better, but I suspect many people wouldn't understand it.) Aside from the obvious problem which has surfaced here, resulting from calling the side opposite where the hair grows as "the hairy side", "hairs" are to individual fibers, not the amorphous roughness resulting from abrasion. You might as well call a skinned knee "hairy".

 

I would suggest that if someone calls the rough side "hairy", you respond by referring to it as "fuzzy" or "rough". They will certainly understand what you mean; you won't be perpetuating a misleading misuse of the language; and they might even adopt your terminology.

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Anyone care to venture an opinion as to why changing the valves would change the tuning. It makes no sense to me.
While I don't know the mechanics of it, the pitch of a reed is partly dependent upon the airflow. Whether it's the pressure, speed of air, flow path (cushions, direction, eddies?).... It's nearly impossible to secure a new valve with exactly the same amount of vent covering as the old one, and the new one will be different in flexure. Generally speaking the more restrictive the valve is to the vent, the higher pitched the reed will become.

 

Granted we're only talking a few hundredths of a semitone, but even that is quite noticeable.

 

-- Rich --

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Are not the correct leather terms for skin orientation "flesh side" and "hair" side?

 

 

FLESH SIDE

 

is the side of the skin being next to the flesh ( flesh is the fat and muscle between the skin and the bone)

 

HAIR SIDE

 

the part we shave in the morning

 

 

Flesh is not the same as skin. We eat flesh, we do not usually eat skin.

 

 

Bob

 

 

 

 

I think we are using the term 'hairy side' differently, or else I am totally confused as to which side of the valve shoud be against the reed pan. I was using the term 'hair side' to mean the side of the leather that the hair grew on which is actually the smooth surface of the leather. I think you were using the term 'hairy' to mean the rough or split side. Is this correct?
Ah yes, you are correct. We get so many customers referring to the split side as the "hairy" side that we've been calling it that too so as not to confuse them. I'm going to have to be more careful about the "hair" and "hairy" side descriptions.

 

Not to confuse things, but there are animals which have hair that goes COMPLETELY THROUGH the hide! Now which side is the hairy one? Such as pigs. That's why pigskin is "breathable" - because once the hair is removed there are zillions of air passages from one side to the other.

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