Dutch wooden saxophone pads

[Woodpad]

part 1 irreversible engineering and the conservatory.

Apart from the engineering perspective, the saxophone is a beautifull instrument. The first prority in engineering is to avoid narrow tolerances.
Every tone hole, key, pad combination of a saxophone has at least 12 different measurements that can be regarded as a narrow tolerance.
With 34 toneholes you get more than 400 points that require attention. This makes the playability of a saxophone strongly dependent of the quality of the last repairman that worked on the instrument,
In every conservatory you see that the students flock to only a few maintenance specialists. Also some of the materials used are a bit outdated.

As I am engineer in food processing, who plays the saxophone I have to deal with this schism. So I look at choices for re-enginering the saxophone.
As a lot of saxophone profesionals favor the opposite process I know that this is not a way to earn money. But as long as it improves my sound and gives me peace of mind I don't mind.

In the world outside saxophone players the blue springs have lost to the metalic, grey and copper colored springs. Mainly because they last longer.
On a saxophone the blue springs give more resistance before they move. As your brain already knows that you are moving a key it is redundant information.
I can understand that it is a reassuring feeling for players who always played on blue springs. As you can get used to other types of springs in a few days, it is not a big thing.

Leather seals have been replaced by ceramic seals. Leather has one feature that I like, its possibility to wet mold it with some pressure.
It can addapt on a nano scale to the surface of the tone hole. As the pad is replacable it is good engineering practice to adapt the replacable part to the longer lasting parts.

My first experiments with pads learned me that I didn't like the feel of further pad compression after the pad was closed.
So the pad should fit exactly on the tone hole and the elastic part of the pad should be as thin as possible.
I made a choice for silicone as the elastic layer as it is a long lasting material. Silicone keeps it elastic properties longer than any other material. It also remains chemical stable longer than any other plastic polymer.
The second choice was to mold the silicone against the tonehole, comparable to leather. The difference is that silicone molds only one time while leather can change its shape for a few years.
A layer of 0.5 - 1.5 mm felt comfortable to my finger. The remaining part of the pad is a carier for the elastic material that can be glued to the key cup.

The next part highlights the used materials.

 

[Woodpad]

part 2 Lignin in reeds

When the seal of the pad is a thin flat silicone ring there are various ways to put this ring into the saxophone.
The most simple way is a flat keycup with a ring punched at the location of the tone hole.

Nice idea, but it is much faster to convert a conventional saxophone.
Then you need a cilindrical shaped carier with a ring shaped cut-out, that fits in the key cup.
The material should be inert, solid, durable, chemically safe, without elasticity and light.
After several tests I found a MDF type 4mm sheet for wet conditions. I put a small part in water for 24 hours and measured it before and after. The measurements showed that in didn't change in size, so I thought it would be safe to use it in a saxophone.

I found a cut-compagnie that laser-cut more than a thousend pads in sizes from 6 to 50 mm diameter and started with my experiments. After a few years I attended a meeting with guest speaker Francois Louis. He told me some interesting thoughts on how a tone started in a saxophone. At the end he mentioned an experiment with reeds. When you brush a reed with warm water it can lose its tone very fast. You see a substance leaving the reed which we call "houtstof".

As I know the substances in wood and paper I could identify this substance as lignin and I started a liturature search how lignin could be bound in a reed by other means than using a plastic cover. According to literature it is not easy.
So I assumed that my MDF carriers slowly lose lignin. When enough lignin is lost the MDF loses its solidity. After 8 years of use in a saxophone the original MDF pads still do not splinter but I changed the material to plastic.
I could use the MDF pads to make moulds. And now I use the summer to make enough pads for the winter.

I also changed my cleaning method of reeds to cold water and a knife. If you want your reeds to last, don't use a brush, warm water or alcohol.

 

[DavidUK]

Hi Theo, I read your article here a year ago: A New Concept In Saxophone Pads: MDF & Silicone | The Bassic Sax Blog

I discovered it when doing research for my new type pads and found it interesting. Many thanks.

 

[saxyjt]

Théo, this sounds interesting but images are worth a million words.

I also checked the article and it's not generous in terms of images. I must be a bit thick in the head but I'm not sure I get the whole concept. Something escapes me that might become clearer with pictures.

 

[mizmar]

lignin

Certainly binds across the fibers in a reed and is a key component in their structural integrity - in the wild and in a reed. Water weakens these bonds allowing the fibers to slide past each other and softening the reed and the bonds can reform....
In MDF the fibers are bonded with resin, no? I don't know if the resins used are water soluble...

 

[Woodpad]

d sounds interesting but images are worth a million words.

Just after the article my eyes where in need of an operation and I have only made one picture since then. Luckily this summer I will make a photoshoot of my Van Hall tenor. It has wooden and plastic pads . I will try to make a clear picture how the pads fit in the saxophone, For the next parts I will make some drawings on the positioning of the silicon in the pad.

 

[Woodpad]

In MDF the fibers are bonded with resin, no?

As lignin is 20-30% of the wood the main task in making MDF is to bind the lignin with a polymerization reaction. As it is difficult to do chemical reactions in a solid only a part of the lignin is polymerized. Trespa is a sheet material where the fibers are bound with resin. If they had trespa in 4 mm sheets I would have used it.
It is possible that trespa like materials are sold as MDF.

 

[Alphorn]

Why would you bother about lignin in MDF? I can understand that it is important for the integrity of reeds as those vibrate and any change would affect that. As a carrier it is only about dimensional stability. Sine you describe soaking in water for 24 h had no effect, I wonder what effect the humidity involved by playing the sax would have at all. Sounds to me you are searching for problems where there might be none. I am a non- ingeneer so maybe I am just a bit thick headed.

Alphorn

 

[mizmar]

the main task in making MDF is to bind the lignin

Oh. I thought the point was to bind the cellulose fibers to provide structural integrity.

 

[DavidUK]

You changed mdf to plastic. How are the new plastic ones coming along? I guess machining them needs a different approach but they should be inert at least.

 

[Targa]

Certainly binds across the fibers in a reed and is a key component in their structural integrity - in the wild and in a reed. Water weakens these bonds allowing the fibers to slide past each other and softening the reed and the bonds can reform....
In MDF the fibers are bonded with resin, no? I don't know if the resins used are water soluble...

I think that might be answered with reference to the people whose water tank that was in the loft crashed through the bedroom ceiling after it had a slight leak. Instead of wooden planks it had been placed on now disintegrated MDF boards.

 

[mizmar]

I think that might be answered with reference to the people whose water tank that was in the loft crashed through the bedroom ceiling after it had a slight leak. Instead of wooden planks it had been placed on now disintegrated MDF boards.

I'm not sure if want any kind of answer form people who'd used the wrong material for the wrong job!

 

[JayeNM]

Just after the article my eyes where in need of an operation and I have only made one picture since then. Luckily this summer I will make a photoshoot of my Van Hall tenor. It has wooden and plastic pads . I will try to make a clear picture how the pads fit in the saxophone, For the next parts I will make some drawings on the positioning of the silicon in the pad.

More photos than that, please. Photos of the pads, front, back and profile...uninstalled/loose, photos of how the pads install into the cups (shellac ? glue? nothing ?), and photos (close-ups of the pad sealing on the tonehole with horn fully assembled would be very helpful .

Intriguing notion, keep it up !

 

[Woodpad]

Sounds to me you are searching for problems where there might be none.

The first batch of MDF lasted at least 8 years, which is reasonable. But when I knew that it is not completely inert I looked for alternatives. As an engineer I want pads to last as long as the saxophone. The guy in the sales department might have another opinion.

 

[Woodpad]

How are the new plastic ones coming along? I guess machining them needs a different approach but they should be inert at least.

Until now they are good. You can laser cut plastic, but it was easier to cast them as I had the wooden ones to make moulds.

 

[Woodpad]

Jochem Sitzen made a picture of one of the wooden pads to show the dept of the trench for the silicon (0.5 mm). This pad has a diameter of 48,5 mm. The trench is 3 mm wide.

The procedure for placing the pad in the saxophone has several steps:

1. grind the back of the pad to the required thickness
2. glue the pad in the key cup in a position that the rim of the tone hole is in the middle of the trench.
3. Fill the trench with fresh silicon
4. Close the key on the tone hole. The whole tone hole surface should be covered with silicon
5. Fasten the key cup at the correct height and wait until the silicon is solid.
6. Open the key cup, by pressing against the silicon
7. The rim of the tone hole has made a round path in te silicon. Cut away al silicon that is above this path.
8. look for the siver lining on the path

Every step will be clarified in the next parts.

 

[Woodpad]

Oh. I thought the point was to bind the cellulose fibers to provide structural integrity

It needs more sentences to describe this. In the classic mdf proces it is easier to polymerize the cellulose than to polymerize the lignin. The structural integrity comes mainly from te fibers. The lignin holds the fibers together. When the lignin disappears the mdf becomes more brittle.

At the moment there is a lot of research to improve mdf by increasing the polymerization rate of lignin in a environmental friendly way. The literature shows that this is not an easy step so it gets a lot of attention.

 

[DavidUK]

If the trench is 0.5mm deep, do you fill it only to this depth i.e. scrape it level with the surrounding mdf?

Isn't there a danger of the tone hole rim cutting all the way through the fresh silicon when pressing the key cup to set the height?

 

[Woodpad]

Isn't there a danger of the tone hole rim cutting all the way through the fresh silicon when pressing the key cup to set the height?

I never close the key that far by filling the 0.5 m trench in the pads some days before I need them and squeeze them on a flat plastic surface. So the silicon in this first layer fils the trench to the top level of the mdf.
The remainder of the silicon is brought on just before the key is closed. I try to make this second layer as thin as possible as silicon shrinks slightly in the first 24 hours.

With the two layer method The rim may only press lightly on the first layer, in order not to compress it,, while the second layer solidifies.

I have tried to do it in one layer but you need more corrections afterwards, so it doesn't save time.

 

[Woodpad]

This morning I changed a pad from a 1926 American Couturier saxophone as it started to leak. As the pads on this saxophone look like factory pads it didn't leak for 96 years. It is probably the oldest pad I have ever changed. . Is this a record?

There are still 6 original pads left in the saxophone.