How Flute Pads Work – Part 2 – Straubinger Pads

In the previous article, I described the benefits and drawbacks of the traditional flute pad – still the most commonly-used pad on flutes.  In this article I want to talk about the first break from the mold – the first real changer in the evolution of the flute pad. And that break is…

… the Straubinger pad.

The inventor, David Straubinger, was a real pioneer in his pursuit to develop a better pad. After beginning his research on materials and designs in 1975, he finally came up with a workable product by the mid-1980s.

A decade later, Straubinger pads were becoming popular, and eventually hit a peak when Bicknell Brennan (one of the Brennan Brothers Flutemakers) began using a re-designed version of the pads in their flutes. Since then, the Straubinger pad has become the standard for professional flutes and has lifted the bar when it comes to precision and excellence in flute function.

Qualities that the pad bring to the table are a quicker, more stable response, and a clearer tone.  Many world-class flutes now use Straubinger pads as their standard pad and the pursuit of excellent has prompted competition in pad design by other makers.  We’ll look at those in the following articles.

In a nutshell, the Straubinger pads are, in some ways, a much more stable version of the traditional pad.

What are they made from?

Straubinger pads consist of a hard, cup-shaped, outer shell made from delrin plastic, that contains a synthetic felt layer and an outer covering of goldbeater’s skin. The breakdown looks very similar to the traditional pad:

• Cup-shaped plastic backing
• Synthetic felt material
• Goldbeater’s skin

In essence, it is almost exactly the same as the traditional pad except that it now has two major differences: the card has been replaced with a plastic cup-shape and the main components are now made from synthetic materials. The plastic cup is not completely rigid, so there is a small amount of give in the pad which the repair technician can use to his or her advantage.

How stable are the pads?

The Straubinger pad is virtually unaffected by the environment (for the most part). Under normal conditions, the plastic cup and synthetic felt won’t warp, expand, or change shape in the way that traditional flute pads will.

This means that players can move between warm, dry or humid climates and find no difference to the function of the pads. I have also met players that have become lazy about swabbing their flutes, because the lingering moisture doesn’t change the way the flute plays over time.

So, is there a downside?

Yes, and that downside is heat. If you live in a really hot climate, such as a Queensland summer, for instance, you could find the pads developing some micro-changes that would affect the playability of the instrument. Keeping a flute in a room on the hot side of the house, or even worse  –  leaving the flute in a car, can change everything.

Firstly, the plastic cup, which gives the pad its strength, can soften slightly with heat. The hotter the environment gets, the more flexible the plastic pad cup becomes.  As flexibility increases, it begins to mold and ‘settle’ further into the keycup. The inner surfaces of flute keycups are not always absolutely flat, so there is room to move, and I often see these changes in flute pads when they arrive to me for servicing.

Secondly, the most delicate part of the pad is the goldbeater’s skin, which can shrink or pull tighter when heated. This won’t change the shape of the pad, because the goldbeater’s skin is being held in place by the plastic pad cup. What it will do is decrease the life of the skin and lead to tears along the edge where it folds over the plastic cup, and along the seat where the pad contacts the tone-hole.

It is common for flutists in hotter areas to have to change the pads on a regular basis. If you live in southern parts of Australia or elsewhere in the world where the sun is not quite as strong, you are probably fairly safe, but take care to ensure your flute remains at a reasonable temperature.

Straubinger pad variations

It is now possible to obtain imitations/copies of the Straubinger pad.

The most famous one, made in Italy, is absolutely identical, with just one tiny little difference.

• The plastic pad ‘cup’ is the same
• The synthetic felt padding is the same
• It also uses goldbeater’s skin, but the imitation version is slightly thicker and a little more durable than the original Straubinger pad.

For this reason (the durability of the goldbeater’s skin), I personally prefer the imitation product to the original.

I suspect that the thin skin on the original versions are meant to increase the likelihood of a perfectly flat seal over the tone-holes. Goldbeater’s skin can be a little uneven in texture at times, so using a very thin skin can minimize this problem. Unfortunately, it seems to make the product less durable and, judging by the discussion on various internet forums, is turning many players away from them.

The imitation pads have all the advantages of the original, but are also more durable, making them a more attractive product.

Best use for Straubinger pads

The inflexibility of the pad means that there are limited options for its use.  They must be used on professional-grade flutes or on intermediate flutes that have the following qualities:

• Accurately functioning mechanism
• Strength in the metal that can resist the stresses of general use.

The mechanism must be accurate because a worn mechanism allows a pad to move around.  As a result, different combinations of fingerings cause the pad to close in different ways. Instead, to work properly, a pad must close exactly the same way no matter how it is being depressed.

The material strength is important because weak metal in the body of the flute (usually found in student flutes) can lead to warped tone holes, even with normal day-to-day use. Instead, to enable a proper seal, the tone holes must remain perfectly flat.

The idea behind the pad is to have something so accurate, that the response is enhanced. And this is exactly what it does. Part of the popularity of the pad lies in the fact that flutes appear to become easier to play, with better response and clearer tone.

Fitting Straubinger pads to a flute

Fitting a Straubinger pad to a flute differs significantly to fitting a traditional pad:

• Choice of pad size is a more exact science (Straubinger pads come in a range of diameters, all one tenth of a millimeter apart. Traditional pad sizes are all a half millimeter apart.
• Felt pads require techniques to make them firmer and flatter, to make the pad work at its best, whereas Straubinger pads already have the density and shape that we need. As long as the correct diameter is chosen for the keycup, there is nothing else to do with the pad.
• Felt pads are stabilized by heat and steam to mold them into the keycups. Straubinger pads cannot be molded into the keycups. Instead, techniques must be used to maintain their flat structure.

If a tone-hole is damaged or warped too much, it will need to be repaired before a Straubinger pad can be used with it. If there is a special reason why this repair cannot be done, then a Straubinger pad will not work with this flute.  Another, more suitable type of pad will need to be used, such as the traditional flute pad we discussed in the previous article.

If a keycup is not perfectly flat (and this is common), this is a lot more difficult to manage. This is something that cannot always be detected from outside, but is not always a problem. The delrin shims that are used during installation help to combat this problem so that the pad always remains in its perfect flat condition. If the flute lives in a very hot climate, as I was explaining earlier, then this can soften the stabilizing components of the pad. This means that the pad could shift, creating the need for adjustments to be made.

There are many people that  believe Straubinger pads are like a cure-all for flutes. Unfortunately, Straubinger pads can make a great flute play better, but they cannot do anything for a flute that has a tired or poorly functioning mechanism.

Conclusion

For the professional player or serious amateur, Straubinger pads are standard fare. They have already stood the test of time and have proved themselves to be a valuable asset. Steering away from them in favour of another pad type should be done with serious consideration.

Having said that, there is certainly at least one other alternative that is worth looking into. Before you begin to assure yourself that Straubinger pads are the pinnacle of flute pad manufacture, I would encourage you to read through the next two articles that describe the latest innovations in flute pad design. Straubingers may have a lot of great qualities, but I believe the newer alternatives have even more going for them.

Read about them in the next two articles.