Pad Materials

[RWL]

I'm considering repadding two instruments, and 56 button Edeophone Tenor Treble and a 48 button Wheatstone English treble.  I wanted to try my hand at pad making for my Edeophone's bowing / air valve because it was leaking terribly.  This is intended to be a quick experiment so I bought a chamois (.032-.036" thick), a piece of poster board (.017" thick) and have some craft felt of unknown parentage that's about .080" / 2mm thick.  Having said that I've also been doing a little looking on this site to find the proper materials.  I live about 2 hours from Columbia organ supply so I could run down there and pick the skin myself, but what to buy.

 

Here are my choices at Columbia:  https://www.columbiaorgan.com/columbia-leather-home/products/leather-skins/#valve_leather

My guess is that the first item in the list CPL Columbia Pneumatic Leather is the type I need, but it comes in different thicknesses.  Thin, about .011" thick,  Medium, about .015" thick, Heavy, about .019" thick, Extra Heavy, about .024" thick and Valve leather about .030" thick.  Is this the right leather?  What thickness are you using?  I know from some of the posts here that people have gotten away with using chamois from the auto parts store, and in David Pierceall's case, an old leather coat.  A skin would cost me $60 to $90 US dollars, so I don't want to buy something I don't really need.  Is there a noticeable difference in air tightness between an auto parts chamois and pneumatic leather?

 

Lets deal with the leather first.  I also have questions about the felt, card, sampers and beads that I'll ask when I see your thoughts on the leather.

[Chris Ghent]

Columbia sells smaller pieces than a whole skin, from memory they are about 12” by about 6”. Their pneumatic leather is ideal though in practise almost any leather of the right thickness will do as most of its usual characteristics (strong, flexible, relatively airtight) are voided when it is glued to the felt.  It does not need to be thick, the felt is doing the cushioning. The cardboard is the frame, (choose cardboard that does not delaminate when punched) the felt is the shock absorber and the leather is the seal. Experiments by Terry McGee showed using the leather soft side down sealed best. 

[Skran]

I would jump in (I hope that's ok) and ask if anyone knows where you can get good leather in the EU. I have some experience with exchanging pads, but have always been lucky enough not to have to get the materials myself.After searching the internet, I'm not much smarter. I found this company  https://www.herzogleather.com/en/organ-building-leather/ and was thinking about the pneumatic leather they offer. But a whole skin would be too much for my needs (~50 to 100 pads max).
I would prefer to be able to use the same leather for other things like valves as well (would that be possible?) to keep the hassle of ordering as small as possible.

 

[Frank Edgley]

The thickness of the leather is important. If you use leather that is thicker the than the original there will be less clearance between the pad and the action board. This will affect the volume of the instrument. You don't want to have to bend the arms because the pads are not opening enough. Very few concertinas have fulcrums that are adjustable in height. Personally, I use the thinner pad material. This does not create noise. There is enough padding the mute that.

[Don Taylor]

1 hour ago, Frank Edgley said:

This will affect the volume of the instrument.

Just the volume? 

 

If it does not also affect the response and the tone then would this be a way to quieten a few over loud reeds?

[RWL]

5 hours ago, Frank Edgley said:

The thickness of the leather is important. If you use leather that is thicker the than the original there will be less clearance between the pad and the action board. 

Well, my goose is cooked for the bowing / air valves since I have the chamois already, but even though it's over .030 thick I should have enough room for these.  When you buy a skin, what thickness or thicknesses do you use for your pads?

[alex_holden]

I use the medium CPL, but the heavy or x-heavy would probably be fine. I'm not sure chamois would work as well as CPL for pad facing as it is fairly porous (you can suck air through it). Finding the right thickness and density of felt is more tricky.

[RWL]

12 hours ago, alex_holden said:

I use the medium CPL, but the heavy or x-heavy would probably be fine.

 

Finding the right thickness and density of felt is more tricky.

What characteristics of the felt are important for the pads?  Is there a specific felt that you look for?  The felt I have is of unknown origin, but since most of the felt I've seen in stores is made of polyester, that's probably what it is.  I believe someone here at concertina.net mentioned that JoAnn Fabrics (U.S.) carries wool felt, but I haven't been there to confirm that it's available locally.

 

With regard to the pneumatic leather, is there a reason for preferring the medium over the thicker leather?

[RWL]

On 2/3/2022 at 5:40 PM, Chris Ghent said:

Columbia sells smaller pieces than a whole skin, from memory they are about 12” by about 6”. Their pneumatic leather is ideal though in practise almost any leather of the right thickness will do as most of its usual characteristics (strong, flexible, relatively airtight) are voided when it is glued to the felt.  It does not need to be thick, the felt is doing the cushioning. The cardboard is the frame, (choose cardboard that does not delaminate when punched) the felt is the shock absorber and the leather is the seal. Experiments by Terry McGee showed using the leather soft side down sealed best. 

I had initially thought I'd need to purchase a whole skin in order to do all the valves but I did a quick calculation and I think a 6x12" (15x30 cm) piece would do it.  If all the pads were .625" (16mm) in diameter, I could get between 160 and 170 pads from that sheet, assuming each circle touched.  Not all pads are 16 mm, some are 14 mm and a few seem to be 15 mm so I should be able to get more than 160 out of a single sheet.

[alex_holden]

12 hours ago, RWL said:

What characteristics of the felt are important for the pads?  Is there a specific felt that you look for?  The felt I have is of unknown origin, but since most of the felt I've seen in stores is made of polyester, that's probably what it is.  I believe someone here at concertina.net mentioned that JoAnn Fabrics (U.S.) carries wool felt, but I haven't been there to confirm that it's available locally.

 

With regard to the pneumatic leather, is there a reason for preferring the medium over the thicker leather?

 

The stuff I'm using is wool felt. I got several samples from a specialist felt supplier here in the UK and made some experimental pads from them to see which type worked best, then I had to buy a minimum amount that is probably enough to make many thousands of pads. It's about 1.8mm thick as supplied, cream coloured, has quite a smooth surface texture, and is dense enough that it doesn't get a lot thinner when you lightly press it during the gluing process.

 

No particular reason for choosing the medium CPL leather. I bought a skin of it and it proved to be too thin to make valves, but it works fine for pads.

[alex_holden]

9 hours ago, RWL said:

I had initially thought I'd need to purchase a whole skin in order to do all the valves but I did a quick calculation and I think a 6x12" (15x30 cm) piece would do it.  If all the pads were .625" (16mm) in diameter, I could get between 160 and 170 pads from that sheet, assuming each circle touched.  Not all pads are 16 mm, some are 14 mm and a few seem to be 15 mm so I should be able to get more than 160 out of a single sheet.

 

In my experience you won't be able to place the holes right up to each other because the punching process damages the card in a circle around the punch entry point. I regrind and sharpen my punches so they cut cleaner and don't cause as much damage to the pad stock:

https://www.instagram.com/p/CZEaGtZI4_G/

 

[Chris Ghent]

I endorse everything Alex has said in this thread. 

[RWL]

On 2/6/2022 at 2:50 AM, alex_holden said:

 

I regrind and sharpen my punches so they cut cleaner and don't cause as much damage to the pad stock:

https://www.instagram.com/p/CZEaGtZI4_G/

 

I'm not on Instagram and am hesitant to have yet another company tracking my viewing in order to sell me stuff.  Can you post the photos here?

[alex_holden]

 

 

Instagram caption: "I ground and sharpened a new 19mm arch punch for making pads. As supplied, they are way too chunky, have firescale inside the hole, and are not sharp enough to cut cleanly. This will be used initially for the air pad on No. 12."

[Daveylocker]

Harbor Freight also sells an assorted set of these type of hole punches that should work well if they are large enough. I truly do admire your machining abilities thought, along with the photography. Fine craftsmanship!

[Don Taylor]

I would like some advice about card stock for pads. 

 

The heaviest weight that I can easily buy is Accent Opaque Digital Cover White Smooth, 120lb from Amazon.  There are 150 sheets in a ream pack so, by my reckoning, each sheet is about .4mm thick.

 

This is quite a bit thinner than the stock used on the old pads (which looks more like cardboard than paper stock) so I am concerned that it might not be thick enough or stiff enough.

 

Is there any reason that I should not glue several layers of the above stock together to make a thicker, stiffer base for the pads?

 

Added later:  I have since found this stuff which is 2mm thick: Cricut Heavy Chipboard - 11”x11” - 5 Sheets - Brown

 

Edited February 7, 2022 by Don Taylor

[Dana Johnson]

Just for reference, the extra heavy CPL from Columbia is heavy only in the context of organ pneumatics.  It is too thin for valves for notes below midrange.  Their “valve” leather is substantially heavier.  But the valves in question are organ valves.  I wish they would carry their CPL in “ultra heavy “ around .028-.032”  their skins are not that even in thickness and the top number they list for each weight may only be reached on dome pieces.  I always thouroughly wet it and dry it on glass because it Is tumbled softer than good flap valves should be.
Dana

[Don Taylor]

1 hour ago, Dana Johnson said:

Just for reference, the extra heavy CPL from Columbia is heavy only in the context of organ pneumatics.  It is too thin for valves for notes below midrange.  Their “valve” leather is substantially heavier.  But the valves in question are organ valves.  I wish they would carry their CPL in “ultra heavy “ around .028-.032”  their skins are not that even in thickness and the top number they list for each weight may only be reached on dome pieces.  I always thouroughly wet it and dry it on glass because it Is tumbled softer than good flap valves should be.
Dana

So I still do not know what to buy for valves for reeds below midrange (C4?).

 

How about this from Columbia:

CCL™ Flap Valve Leather

This leather is made from our Chrome Tanned Cow Hide which has been pre-stretched especially for flap valves. It is a rich, chocolate brown color and it is useful for reed organs, player pianos and any pneumatic pump where a flap valve is needed.  It is approximately .065″ thick, however we can split this leather to any thickness you request.  Since these skins are so large, (20 to 30 square feet in 1/2 skin), we are pleased to offer them pre-cut to your specifications.  The cost is $.15 per square inch plus a $9.00 cutting fee per order.  For example, if you needed a 3″ x 13″ piece, you would multiply 3 X 13, which equals  39 square inches, multiplied x $.15, this would cost $5.85 plus the $9.00 cutting fee.  The cutting fee is applied to your entire order only once no matter how many pieces you have cut.

If so, should I get it split to a thinner thickness?