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Nov 30, 2021 - 7:52:29 AM
73 posts since 11/10/2021

I have an old Tenor Banjo (c. 1917). When the strings are up to tension the neck tilts (doesn't bow) forwards, raising the action and causing intonation issues. I remedied this by placing washers between the neck heel and tension ring to keep it more level.

Are washers an acceptable way of doing this or is it a bit sloppy?

Nov 30, 2021 - 8:19:35 AM

leehar

USA

43 posts since 2/18/2018

I did the same thing on a Harmony open back with the Bakelite shell. It worked just fine. Probably not the recommended method and I wouldn’t do it on my Gibson or my Gold Star but it made the banjo playable.

Nov 30, 2021 - 8:21:14 AM
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117 posts since 12/19/2017

I usually use wood shims because of the way it transfers vibration to the pot. This creates better tone in my opinion.

Nov 30, 2021 - 8:37:35 AM
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beegee

USA

22570 posts since 7/6/2005

I use credit card shims cut to fit. They are cheap, they don't rust, they transfer vibration as well as wood, they are inert, they don't absorb moisture

Nov 30, 2021 - 8:52:13 AM
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14436 posts since 10/30/2008

Washers are flat, so they won't "quite" conform to the radius of the neck heel cut and the rim. Will probably leave significant imprints. Thin shims of brass or hardwood (maple) are more typical. That's what I have used in my Gibsons that needed a tweak in action height.

Nov 30, 2021 - 9:43:12 AM

14137 posts since 6/29/2005

Here's a chart showing the speed of sound transmitted through various materials—wood is by no means the fastest. 

Steel or stainless steel would make better shims if you believe that transmitting vibrations from the neck into the rim has some "sonic merit".

Personally, I would want the shims to be made in a way and with a material that made a very rigid and unyielding mechanical connection.

Nov 30, 2021 - 9:56:33 AM

2125 posts since 2/4/2013

The first banjo (actually guitar banjo) I bought was a bottlecap badged as an SX. These came with washers acting as shims. The same thing was found on the five string. To me it was a sign of poor quality.

Nov 30, 2021 - 11:17:42 AM

14436 posts since 10/30/2008

It just occurred to me you might mean putting shims over the neck lag bolt???

That's going to push the rest of the "meat" of the neck heel wood out of contact with the rim. Skimpy contact of neck heel wood with the rim is always bad for sound/tone. Always best to have a perfect match in the fit of the neck heel wood against the rim. That's why the builders take great care to match the radiuses (radii?) of the neck heel wood to the rim wood, for intimate contact. It also helps with structural strength and neck stiffness.

Nov 30, 2021 - 11:30:52 AM
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11933 posts since 10/27/2006

quote:
Originally posted by beegee

I use credit card shims cut to fit. They are cheap, they don't rust, they transfer vibration as well as wood, they are inert, they don't absorb moisture


I cut mine from celluloid picks. They conform to the shape I need as a credit card will but they are gauged. A Fender style Medium is normally .072". The tortoisoid is usually impossible to see between the neck heel and rim..

Nov 30, 2021 - 11:44:53 AM

9176 posts since 8/28/2013

If the neck pulls up with string tension, thr nrck attacment hardware may not be tightened properly or missing altogether. Worse yet, the neck heel-to-dowelstick glue joint might be loose. In that case, shimming will only be a temporary fix. Loosen the strings and see if you can wobble the neck; if you can, you need to address that neck hardware or glue joint.

I never shim against the tension hoop. I've seen the hoop didtorted that way due to the pressure from string tension. The shim, should go between the wood of the neck and the wood of the rim.

I think others have already explained why washers do not make good shims.

Nov 30, 2021 - 12:58:14 PM

73 posts since 11/10/2021

quote:
Originally posted by G Edward Porgie

If the neck pulls up with string tension, thr nrck attacment hardware may not be tightened properly or missing altogether. Worse yet, the neck heel-to-dowelstick glue joint might be loose. In that case, shimming will only be a temporary fix. Loosen the strings and see if you can wobble the neck; if you can, you need to address that neck hardware or glue joint.

I never shim against the tension hoop. I've seen the hoop didtorted that way due to the pressure from string tension. The shim, should go between the wood of the neck and the wood of the rim.

I think others have already explained why washers do not make good shims.


Yes, the neck does wobble. The hardware is there but very basic: just a metal bracket. Maybe I could do something to make this a tighter fit instead? 


 

Dec 1, 2021 - 9:54:10 AM

9176 posts since 8/28/2013

You need to check the neck-to-dowelstick glue joint. From what you describe as symptons (neck pulling up, neck wobble) that glue joint sounds suspicious. If the joint has loosened up, nothing can be done to tighten it without regluing the dowelstick and properly re-setting the neck angle when it's being done. That's a difficult job probably best left to a professional.

Dec 2, 2021 - 1:12:33 PM

73 posts since 11/10/2021

quote:
Originally posted by G Edward Porgie

You need to check the neck-to-dowelstick glue joint. From what you describe as symptons (neck pulling up, neck wobble) that glue joint sounds suspicious. If the joint has loosened up, nothing can be done to tighten it without regluing the dowelstick and properly re-setting the neck angle when it's being done. That's a difficult job probably best left to a professional.


Just took it apart and the glue joint is solid. When trying to wobble the neck around, the whole dowel stick wobbles with it (only by 1mm). 

Dec 4, 2021 - 7:56:05 AM

95 posts since 5/27/2019

quote:
Originally posted by Ken LeVan

Here's a chart showing the speed of sound transmitted through various materials—wood is by no means the fastest. 

Steel or stainless steel would make better shims if you believe that transmitting vibrations from the neck into the rim has some "sonic merit".

Personally, I would want the shims to be made in a way and with a material that made a very rigid and unyielding mechanical connection.


I suspect that better banjos actually have rims and necks that are more acoustically inert than lesser banjos (e.g. thicker rims made of stiffer and denser woods; necks made out of stiffer woods that incorporate additional stiffening elements).  Meaning that if transmission of vibration through the neck to the rim makes a perceptible impact on the banjo's sound, it's probably not a good thing.  A rock-solid connection between neck and rim would help with that.

Dec 4, 2021 - 11:33:24 AM

12588 posts since 6/2/2008

Years ago I bought a pack of 10 maple veneer cards on Etsy to use as shim material for necks and tone rings. Similar to these. The wood in the ones I linked to here isn't specified, and this is a different seller. You could just get veneer. Or use metal or plastic.

Dec 4, 2021 - 1:40:47 PM

14137 posts since 6/29/2005

quote:
Originally posted by Uke-alot
quote:
Originally posted by Ken LeVan

Here's a chart showing the speed of sound transmitted through various materials—wood is by no means the fastest. 

Steel or stainless steel would make better shims if you believe that transmitting vibrations from the neck into the rim has some "sonic merit".

Personally, I would want the shims to be made in a way and with a material that made a very rigid and unyielding mechanical connection.


I suspect that better banjos actually have rims and necks that are more acoustically inert than lesser banjos (e.g. thicker rims made of stiffer and denser woods; necks made out of stiffer woods that incorporate additional stiffening elements).  Meaning that if transmission of vibration through the neck to the rim makes a perceptible impact on the banjo's sound, it's probably not a good thing.  A rock-solid connection between neck and rim would help with that.


Agreed!

Dec 4, 2021 - 5:25:15 PM

9176 posts since 8/28/2013

quote:
Originally posted by adamrhowe
quote:
Originally posted by G Edward Porgie

You need to check the neck-to-dowelstick glue joint. From what you describe as symptons (neck pulling up, neck wobble) that glue joint sounds suspicious. If the joint has loosened up, nothing can be done to tighten it without regluing the dowelstick and properly re-setting the neck angle when it's being done. That's a difficult job probably best left to a professional.


Just took it apart and the glue joint is solid. When trying to wobble the neck around, the whole dowel stick wobbles with it (only by 1mm). 


I don't quite understand what you are saying here by stating "only by one millimeter." there should be no wobble at all, unless you haven't fully disassembled and actually held the neck in one hand and the dowel in the other. I suspect that's the case, and that you have partially disassembled and are simply rocking the entire neck/ dowel assembly while it's still in the pot.  

If that's the case, you need to pull the entire neck/dowel out and then check it for wobble at the joint. Simply rocking the unit while it's still partway in the banjo doesn't apply enough force to determine what may actually be going on.

If you then find there is no wobble, you will need to check the attachment hardware for screws which may need to be tightened, and also check the bolt at the tailpiece end for tightness. Hopefully, you don't have any glue joint issues and merely need to tighten the crews holding the hardware at the front and the bolt at the back. 

Dec 5, 2021 - 2:00:15 AM

73 posts since 11/10/2021

quote:
Originally posted by G Edward Porgie
quote:
Originally posted by adamrhowe
quote:
Originally posted by G Edward Porgie

You need to check the neck-to-dowelstick glue joint. From what you describe as symptons (neck pulling up, neck wobble) that glue joint sounds suspicious. If the joint has loosened up, nothing can be done to tighten it without regluing the dowelstick and properly re-setting the neck angle when it's being done. That's a difficult job probably best left to a professional.


Just took it apart and the glue joint is solid. When trying to wobble the neck around, the whole dowel stick wobbles with it (only by 1mm). 


I don't quite understand what you are saying here by stating "only by one millimeter." there should be no wobble at all, unless you haven't fully disassembled and actually held the neck in one hand and the dowel in the other. I suspect that's the case, and that you have partially disassembled and are simply rocking the entire neck/ dowel assembly while it's still in the pot.  

If that's the case, you need to pull the entire neck/dowel out and then check it for wobble at the joint. Simply rocking the unit while it's still partway in the banjo doesn't apply enough force to determine what may actually be going on.

If you then find there is no wobble, you will need to check the attachment hardware for screws which may need to be tightened, and also check the bolt at the tailpiece end for tightness. Hopefully, you don't have any glue joint issues and merely need to tighten the crews holding the hardware at the front and the bolt at the back. 


I am reluctant to remove the neck as the assembly is very primitive (not really sure if it was ever designed to be removed!). You have to unscrew one of the head hook brackets that lies under the tailpiece. Because it is so old, I don't want to ruin the threads. When I removed the head, I could see the neck-dowel joint and it looks like one seamless piece of wood. The neck attachment hardware is equally primitive and is just a 'push-in' bracket (as pictured in previous post). I've pushed this in as far as I can and it seems to be fine.

Dec 5, 2021 - 5:37:19 AM

9176 posts since 8/28/2013

quote:
Originally posted by adamrhowe
quote:
Originally posted by G Edward Porgie
quote:
Originally posted by adamrhowe
quote:
Originally posted by G Edward Porgie

You need to check the neck-to-dowelstick glue joint. From what you describe as symptons (neck pulling up, neck wobble) that glue joint sounds suspicious. If the joint has loosened up, nothing can be done to tighten it without regluing the dowelstick and properly re-setting the neck angle when it's being done. That's a difficult job probably best left to a professional.


Just took it apart and the glue joint is solid. When trying to wobble the neck around, the whole dowel stick wobbles with it (only by 1mm). 


I don't quite understand what you are saying here by stating "only by one millimeter." there should be no wobble at all, unless you haven't fully disassembled and actually held the neck in one hand and the dowel in the other. I suspect that's the case, and that you have partially disassembled and are simply rocking the entire neck/ dowel assembly while it's still in the pot.  

If that's the case, you need to pull the entire neck/dowel out and then check it for wobble at the joint. Simply rocking the unit while it's still partway in the banjo doesn't apply enough force to determine what may actually be going on.

If you then find there is no wobble, you will need to check the attachment hardware for screws which may need to be tightened, and also check the bolt at the tailpiece end for tightness. Hopefully, you don't have any glue joint issues and merely need to tighten the crews holding the hardware at the front and the bolt at the back. 


I am reluctant to remove the neck as the assembly is very primitive (not really sure if it was ever designed to be removed!). You have to unscrew one of the head hook brackets that lies under the tailpiece. Because it is so old, I don't want to ruin the threads. When I removed the head, I could see the neck-dowel joint and it looks like one seamless piece of wood. The neck attachment hardware is equally primitive and is just a 'push-in' bracket (as pictured in previous post). I've pushed this in as far as I can and it seems to be fine.


I am glad to hear that the neck attachment hardware, when pushed in, seems to sol;ve the problem. It's likely it wasn't as tight as it should have been due to age. (attachment hardware is one of the first things I check on old banjos). 

As far as stripping the tailpiece end tail[piece screws, that is actually unlikely. But a bit of some penetrating lubricant would be wise on all the brackets should you need to change the head later.

It's not usual for the neck and dowel to be one piece, but it is sometimes the case. More than likely, the dowel is mortised into the neck. But because you seem to have solved the problem, that's a moot point. If everything is tight, as it should be, you can shim the neck heel to get the proper action, or change the bridge height. Just don't overdo the shim thicness, use something besides washers, and place the shim below the tension hoop if there is room to do so.

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