How To Vacuum Test A Flute

When doing repairs or checking the fit of plugs, pads, and cork, we use a simple test in the workshop to check for leaks and ensure that the various parts of a flute are airtight. The good news is, you don't need to be a skilled repair tech to do this at home, and anyone can learn to diagnose a leaky flute part.

You can do this test on any section of a flute, and while we use it most often to check a head-joint for leaks, it also works to check for leaking pads.

It's best to check each piece separately. For instance, to check a headjoint, remove the barrel and hold the head with a thumb or forefinger over the embouchure and place your lips on the metal tube end. Draw air out of the tube to create a partial vacuum, and keep the seal with your lips or tongue. You should be able to feel the resulting pressure as air tries to get back into the tube. After a few seconds, remove your lips, and there should be a slight "pop" as the pressure equalizes. If the tube is leaking, you won't be able to maintain this vacuum, or it won't hold for long and you'll feel the pressure reduce as air passes back into the head through the leak.

It's possible for a head to leak either around the plug or between the metal of the head tube and the wood of the headjoint, so if you detect a leak, the next step is to ascertain where the leak is coming from. To do this, remove the end cap and cover the end of the head tube with the palm of your hand so that the end is sealed, keep the mouth hole covered as well, and repeat the above suction test. If the leak is no longer detectable, it's likely that simply replacing the plug will solve the problem. If on the other hand, the leak is still present, a more delicate repair to seal the head tube may be needed. Our plugs (which are carefully fitted and faced with sheet cork) are very unlikely to leak so if a head is leaking, there's a good chance that the latter situation is to blame, with air leaking between the tube and wood of the head.

To check a midsection or footjoint for leaking pads, it is necessary to cover all the holes and repeat the suction test as above. With a one-piece midsection this is a little tricky, as you'll need both hands to cover the finger holes, so you'll have to either enlist a friend to help by covering the bottom of the midsection, push it against the bare skin of your leg to seal the end, or seal it in some other way. If you find a leak, it's probable that one of the key pads is not sealing properly and may need to be replaced, or that one of the springs needs to be adjusted.

Related Notes on Oiling:

It is possible for congealed oil and dust to get into a keyway (especially if you're over-oiling your flute) and cause the key to bind in the slot so that it is not able to freely return to a closed position as it should, which can cause a leak. It's a good idea to familiarize yourself with the action of the keys so that you can feel the difference when a key is binding in the slot.

When oiling a flute—generally inside only and no more often than needed—it's important not to over-do it. It's best to do this before playing the flute rather than after, so that the bore isn't saturated with moisture from playing. Aim for a light coat of oil that is not enough to run down the bore or cause drips. If you sight down the bore against a bright light, it should look shiny after oiling (in contrast to the dull, dry, matte look before oiling). Let it sit for a few minutes, then use a dry rag or paper towel on a cleaning rod to swab out any excess that could build up on the bore and the recesses that the keypads hit. We recommend almond or olive oil rather than bore oil. Petroleum-based bore oil is supposed to be non-hardening, but we have had some customers complain that it has built up on the bore and gummed up the keys and/or pads.

Here's an example of a flute that has been over-oiled and the keys not removed or protected from the oil:

You can see above how the oil has built up on the pad, interfering with the sealing action of the key, which is why is is a good idea to remove the keys when oiling, or to protect them with a twist of plastic wrap until you've allowed the oil to soak into the bore and then swabbed out the excess:

We hope this description will be helpful in explaining the process of a "vacuum test" and enable you to check your flute for leaks if something doesn't feel right. Happy fluting, and as always, drop us a line if you have a question!

Flutes & Humidity

Here in the fluteshop, we like to take every opportunity to remind flute players and our customers that like many musical instruments, wood flutes are quite sensitive to humidity and will swell or shrink as the wood absorbs or loses moisture from (or to) the surrounding environment. In the wrong conditions it's quite possible for a flute to crack, and even though we take great care to season our wood properly to reduce this risk, there are some steps you must take if you share your home with a flute or travel with one. If you can't find a "flute terrarium" like this one, never fear! There are some simple things you can and should do to protect your flute.

The first thing to be aware of is the ever-changing relative humidity (RH) in the geographical area and individual living space in which the flute is kept. While it's not important to understand all of the relevant physics (we can't all be meteorologists, right?), note that the volume of moisture needed to reach a given RH changes with air temperature—thus in winter, conditions tend to be drier, especially indoors with forced-air and most other heating systems. As far as we have been able to ascertain, the ideal humidity range for a wooden flute is about 45-60% (possibly 50-60% for antique flutes which may not tolerate drier conditions as well as modern ones). However, indoor humidity in a home can be much lower: easily 25% in many areas of the U.S. and so extra care is needed to protect your flute from the possibility of cracking.

Step 1: Get an Accurate Hygrometer

In our experience, these things aren't always calibrated correctly, so its a good idea to

get a several and check them against each other. If you have three or four and they all agree except for one, you can be reasonably certain that those with similar readings are correct. If you get the type with an additional sensor and place it outside, you'll be able to see what the outdoor conditions are as well. This can give you a heads-up when there is a change in the weather and it's about to get dry indoors.

Step 2: Keep an Eye on the Humidity

Depending on where you live, the climate may be more or less of an issue. Ireland for instance has wetter weather than most places in the U.S., but even in wet climates, indoor

humidity can be much lower than outdoor, depending on how the home is heated or cooled. It's a good idea to swab excess moisture out of the flute after playing and to keep a hygrometer in the case as well. This is especially important when traveling. Alternatively, in

very dry conditions it may be beneficial to refrain from wiping all of the moisture out of the flute and allow the condensation inside the bore to keep the conditions in the case from drying out. A smaller device like the one seen at right can be placed inside the case—particularly critical when going from a relatively wet climate to a drier one. For example, if you live in Virginia and take a trip to Arizona, be aware that you're moving from a medium-humidity environment to the literal desert and need to take extra precautions. No one wants their flute to end up like this...

Step 3: Ideas for DIY Humidors

Depending on the above variables, it can be quite difficult to maintain the proper humidity. During a recent test we performed at home, the RH was below 30%, even after running a humidifier on high for 48 hours. In this instance it is best to keep flutes in something with a sealed vapor barrier, even if it is just a large, heavy-duty ziplock bag. We have yet to find an affordable humidor option designed for flutes, so start with a bag with a hygrometer inside and then work your way up from there.

The next step up and the simplest is a plastic tub with a rubber seal integrated into the lid. One of these made by Sterilite is a good solution, especially if you have multiple

flutes, and the clear sides allow the hygrometer to be seen without opening the lid. The rubber seal is important because the bins without them tend to dry out too quickly. You can place a cut half of an apple or a damp sponge inside to act as a time-release moisture holder and then keep an eye on the hygrometer so you know when to change it out.

If you really want to go all the way down the RH rabbit hole and make something a little nicer to look at, it's actually not difficult to make a home humidor out of a wall cabinet with a few basic tools. Our in-house mad genius Aaron Olwell created one for flute parts in the shop by sealing around the door of a wall cabinet with foam rubber, cutting a hole in the door (that is then taped over with clear tape), affixing a hygrometer to the inside, and then putting in a moisture source. Some trial and error may be needed to get the right amount of moisture going inside, but then you have a stable place where it is easier to control the RH.

However you choose to do it, don't forget to monitor the environment in which your flutes are kept, and make sure it doesn't get too dry. Remember, a dry flute is a sad flute!

A Midwinter Move for the Fluteshop

“God is change.”

-Octavia Butler

At long last, it’s moving day for Olwell Flutes! We finally finished the dual purpose workshop/living space we've been building for many years, and just before Christmas, we began the process of moving shop.

It’s been a long time coming and we are so excited to be setting up in the new space that we thought we’d share a little history and some scenes from the move. It also feels like a good opportunity here at the start of a new year to pause and reflect in gratitude for workshops new and old…

In 1988 we moved into a rented space on the upper floor of an old brick building in Massies Mill Virginia, never thinking that it would house the business for the next thirty-four years. The site itself had originally been a bank, constructed in 1921 to serve what was then a bustling small town with a railroad depot, two sawmills, and a host of businesses, but the Great depression took its toll and the bank shut down in 1931. Times changed as they do, and by the 1980s the entrepreneurs, industry, and bankers had left for greener pastures and the railroad had stopped service to the depot. There wasn’t much happening in Massies Mill but that meant an affordable space for a budding flute business—and a weaver friend of Patrick's who rented the downstairs—to set up shop.

View from the window of the Massies Mill Shop, Winter 2023

The old bank building housed us—often in more ways than one—while we gradually transitioned from making bamboo flutes and selling them at arts and crafts festivals to

custom-made conical-bore simple system wooden flutes and doing our best to complete the many orders that continue to fill our infamous waiting list.

Through the years in Massies Mill, we made flutes, swam in the river in summer, and stoked the wood stove in winter. Patrick gradually outfitted the workshop with a collection of vintage machinery, did countless hours of research on flutemaking and flute history, developed his own designs, and became one of the world’s most respected flutemakers; Matthew and Aaron played with tools, flew paper airplanes, rode bikes, and grew up working in the shop; Rowena made flute cases, worked on the production line, designed show displays and letterhead, and did much of the endless series of tasks both small and large that happen behind the scenes to run a family business; and a long series of friends and flute apprentices worked on the instruments as Olwell flutes went out into the world and became an internationally respected name.

Over time, Aaron went from flute apprentice to master craftsman in his own right, and in recent years he and Patrick have been training Matthew and our other trusty apprentice Seth Swingle, both of whom are working their way along the informal apprentice-to-journeyman path of flutemaking. Through all, the old bank building has been a great creative home to us and an important stepping-stone for the business, but as anyone who’s ever visited and experienced the outhouse can attest, it was and is a bit rustic, so an upgraded workspace has been a longtime dream.

Building the new workshop has been a lengthy labor of love, beginning in 2009 and moving in fits and starts, now gradually reaching completion thirteen years later. Now we are

excited to report that we recently passed our final inspection and so commenced an epic hauling of machinery, tools, wood, and materials to the new space, and we’re excited to start making instruments here. We have had fun setting up the machinery and configuring storage for wood and the first few days of making wood chips in the new space have been joyful ones.

Big life transitions are often bittersweet and this one feels especially so, but mostly we are feeling excitement and gratitude to have the opportunity to continue making instruments and to do it in such a beautiful new workspace. Whatever else, it’s the end of one chapter and the beginning of another and we are happy to keep “poking holes in trees” as we say in the fluteshop. Here's to many more years of flutes!

Turning on the lathe for the first time in the new shop...