All musical instruments require routine servicing in order to play optimally. For flutes, that service is called a COA, or Clean, Oil, and Adjust. Flute Center recommends that all instruments receive an annual COA. We perform hundreds of them every year. We met with Flute Center's industry-leading Repair Department to explore what happens to your flute when it comes in for a COA.
A Clean, Oil, and Adjust receives its name from the work performed:
- Clean the flute’s tubing
- Remove the old oil and add fresh oil to the mechanism
- Fully adjust the instrument into excellent playing condition
We begin with a thorough evaluation. First, we check for any obvious mechanical issues. Next, we assess the condition of the pads. This evaluation helps determine the cost of the COA, which can vary based on the number of pads that need replacing. It also tells us whether the flute needs something more comprehensive, like significant metalworking or an overhaul. If a flute is determined to be needing a routine COA, the repair team begins with a complete breakdown of the flute.Cleaning
To begin the “Cleaning” process, we remove the steel rods and pivot screws, unhook all the springs, and disassemble each section. While dent and scratch removal is not part of a standard COA, it is included in an upgraded COA+. Now would be the time to remove any dents or scratches, if needed. We gently dip the tube into a special cleaning solution that assists with tarnish removal. The flute sits in the solution for a few seconds before it is removed, thoroughly rinsed and dried. Our technician then lightly hand-polishes the tubes. Important note: A standard COA does not include polishing of the mechanism, though you can request that the mechanism be polished for an additional charge.Oil
Next, we begin the “Oil” section of a Clean, Oil, and Adjust. First, we remove the pins and thoroughly clean the steel rods with a paper towel and denatured alcohol. Then, we clean the insides of the hinge-tubes with a pipe cleaner. The technician uses special pointed Q-tips for hard-to-reach places. Finally, we add a drop or two of oil and reassemble the mechanism, making sure that the keys move freely on the steel. The technician repeats this process for every section of the flute: the footjoint, the right hand section, the left hand section, and an additional section if you have an offset G.Adjustment
Finally, we enter the “Adjustment” phase. This is by far the most time-consuming and difficult part of a COA. This consists mostly of replacing and shimming pads as needed. It takes years of training and practice for a technician to become proficient at shimming a flute - this is truly what separates a professional repair technician from a novice. Using a feeler gauge, the technician lightly closes the key and pulls the feeler gauge away from the pad. We then remove the pad from the cup and use glue to adhere shims directly to the back of the pad. Shims are small, donut-shaped pieces of paper or plastic that come in various thicknesses, some even thinner than a human hair! We replace the pad in the key cup, remount the key onto the flute, and use the feeler gauge again to check the seal. We repeat the process until the feeler gauge shows a perfect seal. Some pads may need to be shimmed many times. Once the pad is fully shimmed, we move to the next pad, and the next, until all pads are sealing properly. The work is tedious and repetitive, but it’s the only method that truly works.Regulate the Mechanism
Next, we regulate the mechanism as a whole, ensuring that all dependent keys work in tandem, and close at the exact same time. We replace any corks and felts that need replacing, check for lost motion, and ensure that spring tension is even across the whole instrument. The technician adds protective tape to prevent any scratches on the flute. After this, we replace your headjoint cork. Over time, headjoint corks shrink and dry out, so replacing the cork is an essential part of the COA. We always write the date of installation on the cork before installing it. Finally, we clean the areas where grit and gunk can accumulate, like inside the embouchure hole. We check the fit between all three joints, making sure they are not too loose or too tight. Lastly, we check the fit of the flute in its case. inserting foam or felt to reduce excess motion.Play-Test
Our COA is now complete. We play-test the instrument to make sure the flute is performing at its best. Your flute is ready for pickup or to be shipped back to you. We’ll see your instrument again next year, when it’s time for its annual COA.