Tech/maintenance Dutch wooden saxophone pads

[Woodpad]

Today I started on the right hand stack of the Couturier by measuring the required thickness of the first pad.

The pad consists of two layers of felt each 2.0 mm measured on the side The leather is around 0.35 mm. There is no carton or paper and you have a layer of leather on the top and on the bottom. So the thickness of the pad was originally 4.7 mm. When the empty key cup is hold parallel to the rim of the tone holethere is a gap of 2.0 mm. The cup is 2.7 mm deep.

As 2,7 + 2,0 =4.7, this is a well made saxophone where they applied the correct sized pad. The saxophone is in tune so I should copy the present height of the key. Now there is a ring in the pad 0.4 mm deep at the axis end and 0.8 mm deep at the right hand side of the pad. So the pad should be 4,3 mm on the axis side and 3,9 mm on the other side.

Time to grind the first pad.

 

[Woodpad]

After grinding the pad it is glued into the cup, The trench was already filled with silicone sealant (grey). The gap between the pad and the tone hole is now around 0.1 mm. A thin layer of fresh silicone is added and the key is mounted in its place with the spring on so it will not touch the tone hole. The two next keys are added (without spring) and the F is key is closed with an elastic band with a closing force of approximately 100 gram. The G/G# pad is now in position on the tone hole and can solidify. By accident the second key scraped some silicone from the G/G# pad so it will need some correction. Against common belief this pad will not be sticky after hardening. When it gets wet it even becomes slippery.

 

[Woodpad]

part 3 roundabout

When I mold the pad in place on the tonehole the mould is incomplete. On the tonehole side a roundabout is formed with some excess material as hedges around and inside the roundabout.
By trimming the hedges and the sides of the talud below the roundabout the profile looks like:

With a leather pad this looks more like:

so it is a bit different.

 

[Woodpad]

Today I found a new way to deal with warped tone holes. I took a plastic pad and heated it until it became malleable.
Then I pressed it on the tone hole until it had the same deviation. Put it in the refrigerator to cool. Now I only have to grind the back of the pad until it fits in the key cup, glue it and finish the silicone ring.

 

[DavidUK]

Rolled tone holes I'm guessing? Otherwise why not simply file the tone holes flat rather than bending to their warped demands?

 

[Woodpad]

Rolled tone holes I'm guessing?

Straight, but someone has already filed it too much and I could buy the instrument on Ebay as decoration.

The minimum level of the chimney is 2 mm and on another point it is already filed to 2.5 mm beyond this point. It is one of the experiments to find the borders between possible and impossible for this type of pad.

I use this saxophone for classical music and it is already in good playing shape with a flat plastic pad. As I didn't like the differences in the thickness of the silicone ring this solution popped up. As I have some concerts with this instrument the placement of the pad has to wait a few weeks.

If it works, its certainly a solution for the north south differences on rolled tone holes.
I think I will expand the idea to flutes too.

 

[Woodpad]

As I am aiming to reduce the thickness of the silicone layer in this synthetic pad, I have to measure the required thickness of the pad with some accuracy.

For the left hand palm keys I take out the leather pad, clean the key cup and reassemble the key. I estimate the distance between the rims of the key cup and tone hole when they are parallel. by holding different sheet materials in between.
To that distance I ad the average depth of the key cup nearest to the axis and the depth of the side across. Than I grind the pad to the required size. Sometimes I have to use shims, but not often.

In this parallel position a leather pad will develop a an even indenture, so I us this as a standard. 3.8 mm is often found for situations where a 4.0 mm leather pad is used so the indentures are aimed at around 0.2 mm. Now there is a large variation in this 'standard' among different brands.

In a 1970 Amati I found a necessary indenture of 1.0 mm to reach this standard. It was consistent for the whole main stack. So this saxophone was designed to have deep rims in the pads. Most brands are less consistent but have more normal values for the designed indentures. An American Couturier saxophone is the most consistent until now.

 

[Woodpad]

A small update on development of the polyester/silicon pads.

Since I retired in October I do a few hours pad work in the morning. It is very relaxing and the morning sun helps to see the small details on the surface of the pads.
The sound of my saxophones still improve by very small changes. As there are a lot of these changes it is still a time consuming DIY method.

The remarks of Stephen on tone holes helped to improve the seal of the Bell pads. It still takes more corrections and time to do the large tone holes compared to the small ones. For the palm keys it is mostly one correction which increases to around 8 (slowly dropping) with the Bell keys.

It is a separate art to put the right amount of pressure to the keys during the solidification of the silicon in the pads, mainly with elastic hair bands and cork wedges. It is not only about pressure but also about the direction.

My padding method for rolled tone holes changed significantly. You can make very wide contact surfaces with the tone hole rim but that is not the optimal solution. The main pressure from the hands is concentrated on the middle mm of the rim and that is the only pressure you need to make a good seal.
The remaining contact surface doesn't improve the seal much and it can grab the top of the rim during opening and closing of the key. So I try to concentrate on that one mm. Hedges of the roundabout are cut to the same height and beyond that mm the silicon is cut in a slope of around 45 degrees. Warm bending of the pads helps with warped rolled tone holes. It is easier to do this work on flutes because of the small pads and the cylindric shape. Also less warped tone holes.

 

[Woodpad]

During the yearly maintenance of my 1956 Hohner President tenor I found a reasonable mechanism why large silcone/ polyester pads require more corrections than small pads.

The last thin layer of silicone paste is put in its place by the pressure from elastic bands or spings that mimic the minimal closing force during playing. On the 14 mm diameter palm keys tone holes the pressure on the silicone paste is is 9 times higher than on the 42 mm bell tone holes. When the correction on the bell keys are too large the pressure is not sufficient to flatten the viscous paste properly before it hardens. It seems that I have to use very thin layers of correction paste for the bell keys.

By doing this maintenance I could see some improvement in my handwork for the last year. Mainly correcting micro leaks and reducing friction in a part of the octave mechanism. The sound is also slightly better.

 

[Woodpad]

The work sequence plan for a saxophone is now:

grind silicone filled pads to correct thickness

glue pads in key cup centered to the tone hole

bring second layer of silicone paste on the pad.

close pads with elastic bands (no rubber) with a force comparable to finger pressure while playing.
All springs are hooked. Check with leak light and add silicone paste if neccesary.
The saxophone has to be in a playing position as some key work is affected by gravity in the 0.1 mm range. Move the saxophone as litle as possible during hardening of the silicone and don't touch the keys.

After hardening, open keys very slowly. Put regulation cork on the main stack

Remove excessive silicone. Correct visual small flaws on the contact area with small amounts of silicone paste. Close keys with minimal force without springs or bands. Check with leak light during closing. Sometimes closing with minimal fgorce leaves a small gap at a position on the tone hole the furthest from the turning axis. This is caused by the elastic action of the original silicone filling. Close this gap with the smallest amount of silicone paste on the rim of the tone hole. Fixate the keys with scotch tape and be aware not to put extra pressure on the keys.

After hardening open keys very slowly and remove excessive silicone.

 

[Woodpad]

Here we have a key that requires a thickness smaller than the key cup.

The original pad (left) has a deep indenture on the axis side and a faint one on the other side. This reduces the life of the pad considerably.

It is a 4.0 to 4.2 mm thick pad, while the location of the key requires a 2.5 mm thick pad to give the pad an even indenture around. I grinded one pad to 2.2 mm (left), just below the rim of the key cup.
. The number 18 is related to the diameter of the tone hole (18.5 mm on the saxophone).

Now I have to glue the pad and install it.

 

[Woodpad]

Does this look strange?

As the pad fals completely into the key cup there is not much to see. The next exotic part of this saxophone is the C# correction mechanism with of two pads in a bunk bed construction.

The lower part seems to be PU. Once it closed wel, but due to aging for 30-40 years the PU hardened on the tone hole side. As the tone hole is not perfectly flat there is now a leak. The glued side of the PU pad is still soft, so the hardening is caused by thing like oxygen and water.

I wonder if this also happens to leather pads with PU coating. Now time to replace it with silicone pads that age slower than PU (or leather).

 

[Woodpad]

This is something you don't see very often, an old German ringed pad. It came out of a Hohner President saxophone with rolled tone holes . It was neatly installed in a repad. You can see that it fitted over the rim of the key cup as the brass ring inside of the pad was made wth an L profile and the leather

With rolled tone holes you have to be very precise with the thickness of the pad. Too thin and it leaks, too thick and the tone hole makes a deep ring in the leather and the key becomes sticky and slow. This makes the combination of rolled tone holes and ringed pads understandable as they define how high the pad sticks out above the key cup.

The Hohner saxophones are known for there technical quality so the must have mastered how to match keys and tone holes. This is not easy, Stephan Howard described this for the ringed Reso Pads as:

The idea was to make a pad that could be fitted very easily - quite possibly by the home-repairer (as was quite common back in the day).
Unfortunately the cups were never quite as level as they ought to have been, and neither were the toneholes. So it was back to square one, in effect.

Unfortunately the repad was not done with the Hohner factory pads but with pads with slighly thicker leather. This gave two problems.

The bell keys showed a gap of 2mm,
The regulating cork of the right hand stack was paper thin but there was not enough room for the F to F# pad.
It was "solved" by using a pad with a smaller diameter that leaked.

By replacing these three pads the sax worked properly. It has a sound with a very strong core.

 

[Stephen Howard]

This is something you don't see very often, an old German ringed pad.

Depends on how many Weltklangs you work on. Given that they (and the Czech Corton) were the de-facto student horn from the mid 60s to the late 70's (at least in Europe), there are an awful lot of old German ringed pads still out there.

 

[Woodpad]

Depends on how many Weltklangs you work on. Given that they (and the Czech Corton) were the de-facto student horn from the mid 60s to the late 70's (at least in Europe), there are an awful lot of old German ringed pads still out there.

Very few Weltklangs and all with repads. In the Netherlands Martins are the most frequent used old saxophones.

 

[Woodpad]

Working on old bari saxophones (Conn crossbar, King Zephyr, Pierret) I noticed that the extra stiffening on larger keys from present bari saxophones are necessary. The contact area between pad and tone hole can shift 0.2 mm when you put the saxophone from upright to horizontal.

Until now I could cut the silicon contact area with the same size as the brass thickness of the tone hole. To compensate for the swivel action I now cut them slightly larger. This was not necessary for tenors.

 

[DavidUK]

So you have to cut a wider circular channel to accommodate this lateral movement over the tone hole, is that correct?

 

[Woodpad]

The channel in the polyester carrier of the silicone ring is still the same. Only in very specific cases the top layer of the silicone ring is cut wider:

• tone hole diameter must be larger than 42 mm
• only one long beam between keycup and axis

For the King Zephyr it was only used for the low C and B keycup (5 and 6cm beams).

The reason for this policy change is to avoid any reward for gorrilla grip. To reach that the pressure to close a tone hole must always be equal even if your playing laying on the floor.

 

[Woodpad]

The left hand palm key for F (E>F) seems to have its own problem area. Ideally if you remove the pad and measure the distance between cup floor and tone hole rim it should be around 3.7 mm when the key cup is parallel to the tone hole. When you put in a 4mm thick pad it will have a 0.3 mm deep ring that will be seated without much problems.

In reality you find a wide range of required pad thickness from 2.7 mm to beyond 5 mm. On the lower end the pad fals completely in the key cup. Above 5 mm you can shim it, but I don't like the look of that so here I grind the pad with an angle. With leather pads it is difficult to find pads below 3 mm, so you have to rebuild them or accept that the ring in the pad is uneven. Bending the key is another solution, but I can not recommended this for the F key.

 

[Woodpad]

Working on a stencil saxophone from around 1970 I measured that the whole right hand main stack required pads 5,6 mm thick. I don't like how that looks so measured how the thickness required by the left hand main stack could be used. By making the axis side of the pad 1 mm thicker tha the opposite site the saxophone would be alright. An alternative solution could be to lower the right hand posts 15 mm, but that is too much work for me.

In such a case 4.6 mm leather pads will leak in a few years unless ugly thick shims are used. I don't name the stencil brand as you don't find this problem in their main products.