How to Fix Sticky Valves
by Arthur Lehman U.S. Marine Band,
edited by David Werden
Some players are able to prevent valves from sticking by diligent maintenance. Most players are not so diligent and occasionally they find that their valves are not working well. 'When valves do stick, many players are able to take the proper steps necessary to restore good valve action. Other players do not know how to cure the problem of sticky valves, however, and certain valve problems are so stubborn that an instrument repairman must be employed. Rarely do valves fail to respond to the skill of a good repairman.
First of all, what are the causes of sticky valves? Let us confine our discussion to piston valves and not get into problems of rotary valves at this time.
Here are the usual causes of sticky valvesi
- dirt - dirt is no doubt the usual cause of sticky valves. Dirt comes from the air in the form of dust and grit and it comes from an accumulation of dirt and sludge which forms in the tubing of the instrument and is forced into the valves slowly by the air blown through the horn. This can cause immediate trouble, intermittent trouble, or, as is usually the case, it causes a slow and gradual buildup on the valve surface. This dirt, combined with lubricating oil, forms a thick, sticky film which causes much sticking.
- rust - acids from the saliva often cause the valves to become pitted. Once pitting occurs, the pits usually rust. This rust extends above the surface of the valve - it seems to rise up - and, thus, causes the valve to stick.
- Lack of lubrication - some kind of lubrication is necessary for good valve action. Water works well but water doesn't inhibit rust. Oil is most frequently used for oil lubricates well, lasts longer than water (evaporates more slowly), and inhibits rust.
- Heat - heat usually causes valves to dry out quickly and this, then, comes to a sticky condition caused by lack of lubrication. Dry valves simply do not work freely. Dry valves are usually encountered during out of door playing in hot, dry weather.
- faulty springs - there is always a certain amount of friction between the valve spring and the valve casing. ’Whenever a spring binds, bunches up, compresses in a distorted fashion, it can cause valve problems. A good lubricant will help such conditions sometimes but usually new springs are necessary. If the spring is not of the correct kind, if it is too stiff or too weak, or if it is the wrong diameter, it can cause sticking.
- key and slot - a valve has a key (guide) at the top: a casing has a slot. When the valve goes up and down, the key slides up and down in the slot - keeps the valve exactly straight. If the slot is dirty, it will cause the valve to stick. Also, the key can become worn or nicked, twisted or bent, and these conditions can cause sticking, too.
- keep instrument clean - clean the instrument thoroughly inside and out on a regular basis. Be sure to polish valves at these times.
- Lubricate - use lots of valve oil and lubricate daily - whenever the instrument is played, put oil on the valves.
- correct springs - use the proper kind and size of springs with the correct tension. When springs start causing trouble, discard them and get a new set.
- Keys and slots clean - watch the keys for nicks, wear, bends, twists and get a repairman to replace any which aren't right. Clean slots whenever instrument is cleaned, using a wooden matchstick or toothpick; gouge out the dirt.
- fight heat - lubrication is the way to combat drying action of heat. Valves may require lubrication several times during a concert in the heat.
- Flush with oil - while this is not actually flushing, a good plan of action is to run oil from the mouthpiece, into the leadpipe, and down to the valves. In this manner, if it is done daily, it will keep any dirt and sludge which might tend to form in the leadpipe moving through. The oil carries the dirt with it and out of the valve section.
Soap it up several times. Rinse 'well. Then, check the spring. Is it undistorted, even, of the proper diameter and tension? Probably it is o.k. finally, check the casing. Do you feel any dirt? Do you feel any sticky spots? If you do, you must clean the casing, too. Do this by using a mild sand soap, such as "lava" soap. Soap the valve heavily and put it into the casing while hot and wet. Move valve up and down in the casing until the valve moves fairly freely.
Do all of the above to all valves, taking one valve at a time. When you Have sand-soaped all four valves and worked them up and down in the casings long enough so that the springs will lift them, then, practice for an hour or so, including your warmups. After one half hour of this, add valve oil. You don't ever rinse the soap off. The oil will gradually wash it away. As soon as the valves work quite well - easily and freely - lubricate the valves with water. This will cause the valves to become quits slick and slippery. They will work extremely well now.
This almost always causes the sticky valve condition to disappear. If it does not, you may be wise if you do all of the above all over again. Sticky dirty grease is often very difficult to remove completely. The lava soap treatment will do the trick, but it may take two or three applications.
If the valves still stick, the best thing to do is to take the instrument to a good repairman. If the valve key is mutilated or too well worn, a repairman must be employed. If the surface is too badly pitted, a repairman will have to reflate it and lap it in the casing. If the casing is at fault, a repairman can cure this by special means while the individual player can usually cure his own sticky valves, sometimes a repairman is the best, easiest, and safest solution to the problem. It is well to be acquainted with the repairman. He can do wonders with your instrument.