Custom octave key pads

Back in 2010 I published an article about using a new mouldable rubber compound called Sugru to make custom key risers and other ergonomic mods. Ever since then I've been experimenting with this unique product - and so here is my latest Sugru-inspired sax mod...the custom octave key pad.

On the face of it, it doesn't sound terribly exciting - after all, an octave key pad is a rather insignificant part isn't it?
In terms of its size it is, but in terms of what it does and where it sits it's actually quite an important part. If you get a leak in any of the other pads on your horn there's at least a chance that you can 'blow past' it, either by adjusting your embouchure or simply pressing down on the keys a little harder. If the octave key pad leaks it will affect the playability of almost the entire range of notes on a sax, and there's very little you can do about it other than have the pad replaced.
Fortunately this isn't a difficult or an expensive job but unless you had a spare octave key pad handy and the knowledge of how to replace it, it will mean a trip to the repairer.

Chances are your octave key pad is made in the same way as all the other pads on your horn. A felt core with a card backing, wrapped in thin leather.
While this works quite well for the rest of the pads, the octave key pad tends to take rather more punishment. It often gets thoroughly wet, which eventually hardens the felt and makes the leather brittle, and it has to maintain a seat on the pip - which tends not to have as well-defined a rim as a normal tone hole.
So it should come as no surprise that octave key pads need changing more often than the rest of the pads on a sax (with the palm key pads following closely behind).

Many repairers recognise this problem and favour the use of alternative materials for the octave key pads - cork being the most popular option.
On the face of it, cork is ideal. It shrugs off moisture better than a standard leather pad and it doesn't suffer from the stickiness that sometimes plagues these small pads.
However, cork is relatively inflexible and this means it can be rather tricky to set the pad correctly - and in some cases it can be a little noisy in use. Players often report that the 'clunk' a cork pad makes when the octave key comes down can be a bit distracting.
A good compromise is a synthetic pad. These are tough, long-lasting and reasonably quiet in use - but not many repairers keep them in stock.
So why not make your own?

You'll need a few items - as follows:

A sachet of Sugru (your choice of colour)
Superglue (gel for preference)
A flame (a gas lighter will do)
A pointy stick (screwdriver)
A flat blade (table knife)

The first thing to do is to remove the existing octave key pad. This should be held in place with a heat-soluable glue, such as shellac or hot-melt glue. Ordinarily you'd need a small blowtorch to remove a pad, but as the octave key pad is so small a cigarette lighter will easily put out enough heat for the job.
If you haven't got a 'hands free' lighter like the one shown, find someone to hold the lighter for you.
Gently heat the key cup with your flame - it shouldn't take long before the glue melts - and use the pointy stick to apply gentle leverage to the pad as you do so. This ensures the pad will move the moment the glue melts, at which point you simply lever the pad out of the key cup. No need to force it, it will come out easily once the cup is up to heat.
Try to avoid putting the pad into the flame - if it catches fire it'll make a bit of a (smelly) mess - it's enough that the key cup just barely touches the edge of the flame.
Don't risk leaving the lighter burning for too long (especially a disposable one) - if the pad doesn't come out after half a minute or so then there's a chance it's stuck in with something else, and you run the risk of burning any lacquer on the key. Give it up as a bad job and carefully pry the pad out with a small screwdriver.
Once the pad is off, inspect the key cup. Is it relatively clean? If there appears to be quite a bit of glue left in it, heat the cup again and, using a twisted-up corner of a rag, mop out the glue. It'll be hot, so mind your fingers. Don't worry about getting all of it out, a little bit left in the cup will give the Sugru something to hold on to.

While the key cup is cooling down, open up your sachet of Sugru (Handy Hint: Ignore the 'cut around here' lines on the sachet - just cut across one of the shorter ends and peel the foil back a little way. This helps to keep the remaining Sugru usable for longer).
I've chosen some orange Sugru for this job, simply because it makes it a bit easier to see what's going on in the photos and because it more or less duplicates the colour of a leather pad.
You won't need a lot - a lump about the size of a pea is about right. Roll it up into a neat ball with no cracks or lumps, then simply push it gently into the key cup. At this stage it doesn't matter too much what it looks like - this is the 'test-fit'.
What you're aiming for is to fill the key cup evenly and have a 'pad' that rises about 3mm out of it at the centre (below, right) - which roughly duplicates the height of a standard octave key pad.
If you haven't incinerated the old pad you can pop it back in the key cup to give you an idea of the thickness you're aiming for.

You'll now need to fit the crook to the sax.
There's a relationship between the thickness of the crook pad and the distance between the octave key pin (the sticky-up bit that rises above the crook socket/receiver) and the octave key ring. The thinner the pad, the closer the ring will be to the pin. This is a critical relationship - if the pad is too thin the ring will touch the pin, which will in turn prevent the pad from closing fully...so you'll have a leak. If the pad is too thick the ring will be held too far away from the pin, and when you press the octave key you might find that crook key doesn't move at all.
There's another factor to take into account, and it's that the crook can be fitted in a variety of positions. Some players fit it so that the mouthpiece ends up more less in line with the octave key thumb rest - others prefer it slightly to the left or the right - and still others vary it depending on whether they're sitting or standing.
If the ring isn't truly circular you might find that the gap between the pin and the ring varies depending on the angle of the crook.

There's also likely to be some lost motion in the octave key mechanism - even the best of them are still quite crudely built by engineering standards - and all this adds up to a need for a bit of 'breathing space' between the octave key pin and the crook key ring.
As a rough guide, with the crook in its normal playing position and all the keys at rest, there should be a gap between the pin and the ring. This will allow for different crook positions, free play in the mechanism and any settling in of pads and corks over time. If you vary your crook position, set the thickness of the pad at the angle of the crook where the ring is nearest to the pin.
On a good octave mechanism in fine mechanical order (such as on the TJ RAW on the left) it can be as little as 1mm - but for an older horn, or one that's a bit worn or that isn't very well made it could be as much as 3mm.
So this gap is what you're looking out for. If it's not there (and I'm assuming it was before) you need to thicken up the Sugru pad. If it's there but it's much larger than specified, you need to thin the pad out a little.
This is easy enough to do on both counts, either add a bit more to the pad or pull some off. You won't need to remove the Sugru, you can just squish it back into shape when you're done. If in any doubt, pop the old pad in the cup again and see how the ring sits in relation to the pin.

It would make sense at this point to test it. Position your fingers on the horn as though you were about to play a G - and press the octave key. This will raise the body octave key pad, situated a little below and to the side of the octave key pin. Watch the octave key pin. If it moves at all it should hit the octave key ring and come to a stop (the spring on the crook key will be acting against it). This will cause the body key cup to rise.
If the mechanism is a bit off balance you might find that as your thumb presses the octave key fully home, the octave key pin just about raises the crook key. Thicken the pad up and retest.
If all is well, lift your G finger - so that you're now playing a top A. At this point the octave key mechanism will automatically switch from the body key to the crook key. The body pad closes, the octave pin pushes against the key ring and the crook cup rises.
How far it rises depends on how well set up your octave key is - but it should be at least 3mm.
If it doesn't rise enough, check the thickness of the crook pad...perhaps it could go a tad thinner.

Hopefully you'll find the sweet spot - but by now you might have noticed that each time the crook key raises and closes, the octave key pip pushes its way into the Sugru, and this might throw the mechanism out. There's no need to worry about it at this stage - once the Sugru has set it will be quite firm enough - but this will give you some indication of where the pad thickness will end up once you've made the final impression in it.
Now is a good time though to decide on a profile for the pad.
Oh yes, you get to choose exactly what shape you want your octave key pad. How's that for customisation?

The vast majority of horns work just fine with 'any old pad' in the octave key, but a few sometimes show an improvement if the face of the pad has a specific shape. For example, some horns are inclined to 'whistle' if the face of the pad is too flat. Others, particularly those where the crook key is quite worn and can be moved from side-to-side tend to work better with flat pads. To make a truly flat surface, use the blade of a knife.
For my purposes a flattish curve (centre shot, above) works very well.
It's easy enough to experiment - simply shape the pad as you wish and give the horn a blow. If you find the pad keeps sticking you can wrap a little cling film around it, to act as a temporary skin - or just lick your finger and smear a little saliva over the face of the pad. Above all, you must ensure the pad covers the octave pip evenly. This is especially true of a flat pad. It doesn't matter too much if the pad itself is set at an angle and forms a sort of wedge shape, just as long as the face comes down square with the surface of the pip. A curved face presents less of a problem in this regard.

So - you've sorted out the thickness, you've decided on a profile for the pad, now it's time to fix it in place.
The bit of Sugru you've been using for testing might be a bit grubby by now, so feel free to roll up a fresh ball. It might be worth washing your hands first, just to prevent any grime getting onto the fresh Sugru.
As before, push it into the cup and check the thickness. Now remove it again. Turn it over and place it face down on a table and make a very shallow indentation in the back of it. Now unstick the pad from the table - you'll want to be able to pick it up quickly and easily once you've applied the glue. Take up your superglue and place a small drop into the indentation. This is where superglue gel has an advantage over the watery variety, as it's less inclined to run off when you move the pad.
Now, carefully pick the pad up and push it gently but swiftly into the key cup, glued side down.
This adds a bit of security. Sugru's pretty grippy but there are times when it need a bit of help, and the very last thing you want is for your octave key pad to drop out in the middle of a gig.
You could just as easily pop a drop of glue into the key cup instead, but I found there's more of a risk that the glue will be pushed up the sides of the cup when you push the Sugru in - which gets a bit messy.

OK, you're now 'committed'. If for any reason you need to remove the pad now you'll have to clean up the remains that will be stuck in the key cup - so if you need to make any last-minute adjustments you'll have to do them in-situ. Recheck the pad thickness, shape the pad as desired - and now for the final touch...the pad impression.

More choices here - you can choose to let the key fall naturally, and it will make a small impression. You can give it a very gentle push down and it will form a larger impression - or you can hold the key off so that no impression is formed at all. I'd only advise the latter if you're absolutely sure that the key is wobble-free, the octave key pip is dead level and you've got the pad thickness bang on. Notice how shallow the impression is on this pad.
If in any doubt, let the key cup rest on the pip, close off one end of the crook and blow down the other to check for leaks. Don't suck - you might pull the Sugru into the pip.
Finally, wedge the key open with a piece of cork or card.

And now all you have to do is wait for the Sugru to cure.
If placed in a warm room it will take most of a day for the compound to become firm enough to use - but to be on the safe side I'd bank on leaving it until the next day.
You won't have used much of the Sugru in the sachet, so roll it closed and pop it in the fridge to slow down the curing process - if something goes wrong you'll need some fresh Sugru to make another pad. It's helpful to retain any of the waste bits left over from making your pad - just fashion them into a pad-shaped ball and leave it to set alongside the crook. It'll provide a means of testing when the compound has hardened enough to withstand some testing of the fitted pad, which should give you enough time to make a new one if necessary.

Assuming all has gone to plan what you'll end up with the next day is a firm synthetic pad that seals perfectly, isn't too noisy in use and very resistant to wear and tear...and sticking.
If, though, you find that the pad is a little too thin or too thick, and the octave key mechanism is slightly out of balance, you might need to tweak the crook key a little.
This is easy enough to do and only involves a bit of simple key bending.
Hold the crook up in front of you with the mouthpiece cork pointing to the right. Look at the octave key - see how it resembles the letter 'C'?
The ring is on the bottom, the pad is on the top.
The chances are that the pad is a bit thinner than you expected, and will not now close properly, so you'll need to move the ring away from the octave pin. You do this by compressing the key in the manner shown on the left.
There are a couple of things to be aware of. You should keep an eye on the part of the ring that runs up into the main shaft of the key - ensure that during the bending process it doesn't touch the body of the crook...it might leave a small dent or a mark.
Now, there is a risk that you might completely fold the key up - but you'd really, really have to be going for it. As you hold it between your fingers you can feel how springy the metal is...if you compress the key lightly and release it, you can see how it springs back. A gentle but firm squeeze is all that's required.
Fit the crook to the horn - if you've adjusted the key properly there should now be a little gap between the octave key pin and the ring.

There might also be too much of a gap, in which case you'll need to open the 'C' out. You can do this by simply pulling down on the key ring - but this will heavily compress the pad and might damage it, so pop a finger underneath the key cup shaft to cushion it and hold the pad open.
Now, gently but firmly, push the ring down and inwards with your thumb.

Don't be surprised if it takes a few goes to get it right, even an experienced repairer might adjust the crook key half a dozen or so times before getting it exactly as they want it - opening out the key then closing it up - and don't worry about snapping the key, it's not going to break.

As for how long the pad will last - that's an unknown quantity at the moment. Everything else I've made with Sugru has lasted very well, including some mods that get a lot of handling (screwdriver handles, palm key risers etc.) - and the octave key pad I made a few months ago for testing on my own horn looks as fresh as the day it was made.

You'll have plenty of Sugru left over after you've done this job, so it might not be a bad time to think about any other small mods you might want to try. Maybe a custom key riser, for example?

Here's a little mod I made when I was working on the prototype octave key pad. It's just a simple taper on the end of the crook where there'd normally be a step between the end of the mouthpiece cork and the crook's tip ring.
Does it work? Well, it's stayed on...so that's a start - but in all honesty I can't say that I've noticed any change in the tone. It keeps the end of the cork nice and tidy and it stops gunk from building up in the gap, so it has a functional purpose...but you might well find it makes a tonal difference.
It's quite tricky to make though - you'll need to thoroughly clean the area first with a bit of cigarette lighter fluid, and thereafter you'll need a fair bit of patience. I found a wet knife blade was good for shaping the Sugru once I'd wrapped it around the tip, though more often than not it pulled off as much Sugru as it put on. If you get any on the cork you'll find that wiping it off carefully with a cloth soaked in a little cigarette lighter fluid works well.