Moisture problems in the bagpipe can be confusing. The bagpipe needs moisture in order to work at peak efficiency. Too much though, and problems occur. The external conditions whenever we are playing bagpipes are the same for everyone, yet the build up of moisture is not. So what is really going on?
It’s common for pipers to consider themselves a “wet” or “dry” blower. But calling yourself a “wet” blower or a “dry” blower is basically bagpiper jargon. Neither is true. No one expels wetter or dryer air than anyone else. The humidity level of human breath is fairly constant at around 95%. It is biologically impossible for it to be lower or very much higher since the moisture in our bodies is in the form of a saline solution, water molecules bound to salt, which will not evaporate.
There is a reason we don’t see clouds of condensing moisture shooting out of our drones when we play bagpipes outside in the winter or early spring. “Wet” or “dry” blowing is really a function of temperature and resulting evaporation and condensation. The temperature and humidity level of the surrounding air is always going to be lower than your breath (exceptions exist of course, particularly if you live in a desert climate or mountain elevations). The difference will determine how quickly moisture will condense. On average, the temperature of the breath leaving our bodies is 37° C or 98.6° F—body temperature. Everyone is different though, and normal body temperature can be as much as a whole degree lower or higher for some people. Even still, this should make blowing into a bagpipe constant for everyone. Oh, if only that were the case! As bagpipers we are doing two things that change the parameters:
1) Expelling a jet of air at different speed and frequency.
2) Placing air under pressure in a closed system, and then adding more.
The variety found in producing these two things explains the “wet” and “dry” blowing that different pipers experience.
The pressurized air in your bag is going to start to equalize instantly with the surrounding conditions. This means that the new air you put into the bag is always going to be warmer than the air already in it. When air cools, it becomes more humid, even though the moisture content in the air remains the same. The humidity level in the bag will approach full saturation very quickly. What do you think is going to happen? The 100% of water vapor in the cooler air of your bag will instantly begin to condense. Where will that moisture go? It will evaporate into the atmosphere or condense on the coolest available surfaces. That is going to be the surfaces of your reeds and the wood of your drones, inside the chambers and stocks, where it causes the most trouble. A balance is struck when air is expelled from the instrument at greater speed and pressure, which will increase evaporation and reduce humidity, thus reducing the amount of condensed moisture.
It would be nice if these principles were constant. We could control them easily. But alas.
Controlling this process is the reason so many moisture control systems exist in the piping market. Plain tube water traps are so effective and ubiquitous mainly because they provide a point of collection for condensing moisture before it enters the bag and moves through the bagpipe. Many pipers have found success with the different moisture control system out there. These systems do work, but only up to a point. They work best, when the underlying trouble is addressed and remedied.
Check out Part II where we dive into moisture trouble and the solution!
For more insight into moisture issues on the bagpipe, check out these Dojo U classes.