Thursday, June 13, 2013

A Closer Look at Spuds

Last fall, we took a look at what "spuds" are and how they work.  If you didn't have the chance to see it, take a look at  In that post, we highlighted the change in design from soldered spuds to spuds that are "machined" or built into the cup.  Both types have the same function, but what are the differences?

Well, the major difference is in construction.  Soldered spuds are made from brass and are soft soldered into the key cup.  We see these in the repair shop on older flutes, although the change in Powell was made just over 13 years ago.  So, a flute with soldered spuds is not necessarily "old," and other brands may have soldered spuds as well.  A machined spud is built into the cup and is, literally, part of the cup.  The cup's design includes the spud,  so when the cups are made, they are made with spuds!  Unlike the older brass spuds, these machined spuds are made from whatever material the cup is made of -- silver or various types of gold.

The construction also can give you a clear expectation of a spud's "lifespan."  Solder wears over time, so a soldered spud may become loose or ultimately completely detached from the key cup.  There is pressure on the pad from the screw and washer, which in turn causes the pad to pull on the spud.  With a machined spud that is part of the cup, well, the spud is not going anywhere!  It can take as much wear and tear as you can give it, and it will not be pulled out of the cup over time!

So, for those of you with machined spuds, rest assured that your spuds are secure!  For those of you with soldered spuds, do not despair.  Our repair technician re-solders every spud on an overhaul.  They can be easily fixed if you have any problems, and they can be replaced as well.

Soldered spud -- the bottom gets soldered into the key cup.
Close-up - we see the threads where the screw would go in.
Soldered spuds can be replaced.  There is a whole tube of them in this photo!
Machined spud -- will not get pulled out!

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