How to Properly Clean a Cornet or Trumpet.

If you play trumpet or cornet, chances are you’ve spent years practicing songs and making stupid noises to amuse your friends. You’ve probably been taught by a dedicated tutor or laboured gruellingly over the fingering charts, trying to memorize the various notes. What most players aren’t taught, however, is how to clean their instrument. If you don’t clean a brass instrument, all of the spittle (yes, I know it’s disgusting to think about, but it’s true) accumulates in the bends of your instrument. And trust me when I say it isn’t pleasant to lift the mouthpiece up to your lips and notice a smell that reminds you strongly of a rotting corpse. This tutorial will show you how to fully clean your instrument cheaply and (relatively) quickly.

You will need;

  • A bath, basin or something that will hold both water and your instrument.
  • Vaseline or another form of petroleum jelly. You can get this from most drugstores.
  • Valve oil. This is the most important piece of kit aside from your instrument itself, and also the most expensive. Most music stores will sell you it at a range between £3-£5 ( About $5-$8). If you can get it, I highly recommend asking for ‘Blue Juice’. It's one of the best on the market.
  • A cloth/duster and a roll of kitchen towel/toilet roll.
  • An old towel.


  1. The first and most important thing to do is to remove everything from your instrument. And I mean everything. Valves, screws (most cornets will have a screw that stops the frontmost tuning slide from falling off when you pull it out, as will many makes of trumpets), and I suggest taking the valve caps off as well. You should be left with the shell of your instrument. This will allow the water to flow quickly through the instrument.
  2. Next, run a bath. No, I’m not joking. Run a bath of water, quite warm, but not roasting. Do not add in any bath salts or bubble baths. Place your instrument slowly into the water, and leave it for about an hour. This will soften any grit and grime stuck to the insides of your instruments. I usually add the valve caps and mouthpiece in with this for about ten minutes, and then dry them off with some kitchen towel.
  3. While you’re waiting on that finishing, it’s a good idea to grease up your tuning slides. This is where Vaseline comes in handy, but if you don’t have any, valve oil can work just as well. Taking quite a generous amount of Vaseline on your finger, lather it on the part of your tuning slide that goes into the instrument. Rub it into the metal as well as you can, and then take another piece of kitchen towel, and take it all completely off. This removes any grime from your slides. You’d be surprised at how dirty they can get. Add another layer of Vaseline, this one much thinner than before. Leave this layer on. It will act as oil to your slides, allowing them to move freely.
  4. Next give your valves a wipe down. You’ve probably been told not to do this, but it removes any crust, and gives you a clean slate to work with. Taking a cloth, just lightly rub the chamber a few times. Apply your valve oil to the main chamber (this is the part below the spring, with all the holes in it), and sit them down again.
  5. By this point, your trumpet or cornet should be ready to lift from the bath. Before removing it from the water, give it a shake around, firstly from left to right, and then up and down. You might see some flakes coming from the inside, especially where your mouthpiece attaches, but this is normal. Lift the instrument from the water, and put it on an old towel. Shake it carefully for a moment – bell first – to remove any water drops from the main part of your instrument. You now need to leave it sitting for a while. I’d recommend leaving it overnight to fully dry out.
  6. When you’re sure that your instrument is dry, put a little Vaseline onto the exposed slide metal that is on your trumpet. Then carefully replace all of your slides, taking care to wipe away any excess Vaseline. Put your valves back into their respective areas, and re-attach your valve caps. You may need to add a little more valve oil at this point. Blow some air through your instrument to check the valves are in the right way. If you find the air is blocked, turn the valves ninety-degrees at a time, checking to make sure that you can get a clear path of air to the bell.

And there you have it! No fancy sprays, polishes or abrasive cleaners, and nothing too expensive. Just a simple and effective way to clean out the inside of your instrument and keep it smelling fresh! And the best part? You shouldn’t have to do this more often than every six months. That means more time for playing and impressing your friends.

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