Cleaning Pistons

[tubarepair]

Your casing brush should be made with relatively soft bristles and be just larger in diameter than the casing. If it has a sharp tip, cover it to protect the casing from scratches. You can soak the valves in 100% white vinegar to remove scale - about five minutes and be sure to remove any felts first. Rinse throughly (making sure all of the vinegar is forced out of the inside of the valve), reassemble and lubricate.

[Rick Denney]

What's the best way to clean piston valves? Is there a brush that's the right size or a certain cloth or something else?

Also, what's the best way to get the caps off the bottom when they're really stuck? I havent been able to get them off at all.

Thanks!

Gabe *who loves his tuba but hates when she is stubborn like this*

A small toothbrush will work fine for the valves and casings. Get one designed for children.

A small rawhide hammer with a chisel point, tapped lightly at an angle (in the direction of loosening) on the rim of the cap should loosen it. Get a real rawhide hammer, and get a small one. Ferree's sells them. If you damage something, though, don't blame me.

For those of you who own silver tubas, remember that silver against silver will eventually weld together. Loosen mated silver parts from time to time.

Rick "who thinks a small rawhide hammer is a necessary tool, and not likely to do too much damage" Denney

[Dan Schultz]

Gabe *who loves his tuba but hates when she is stubborn like this*

Your tuba is female? Post a picture.

[tubarepair]

For the rawhide mallet...

Rick mentioned Ferree's Tools (Battle Creek, MI)

I'll suggest Rio Grande Jewelery Supply (Albuquerque, NM) as well. Both have toll free numbers, just dial 1-800-555-1212 and ask for 'em. Daryl

[kegmcnabb]

For those of you who own silver tubas, remember that silver against silver will eventually weld together. Loosen mated silver parts from time to time.

Wow! Thanks for the info. I'm going to go loosen my bottom caps right now. My Marzan is my first silver tuba.

Once again TubeNet saves my

THANKS Rick!

[TMurphy]

Before you resort to the rawhide mallet, get one of those cloth rubber jar openers, and use that to get a good grip on the valve caps. That might give you the extra grip needed to get it open. If that don't work...mallet away.

[Art Hovey]

Most of the experts here seem to favor mallets for loosening stuck valve caps, but I use a large pair of pliers, the kind with a slip joint so that you can adjust the gap between the jaws. First I glue pieces of popsicle stick to the jaws, using "Goop", a kind of rubber cement available in most hardware stores. The wood protects the brass valve cap from scarring and grips the knurled edges of the valve cap pretty well. I think this method puts less stress on the metal than hammering; perhaps someone will explain how I am wrong. A little heating can also be helpful in stubborn cases.

I also find that on some tubas you can get the valve cap to turn, but not all the way. Apparently crud builds up in the threads. In such cases it is necessary to turn the cap back and forth repeatedly, using the pliers if necessary. The crud gradually gives way until you can finally unscrew the cap all the way. I think this gentle, repeating motion puts a lot less stress on the instrument than forcibly unscrewing the cap all the way against resistance.

I have seen two instances of brand new piston sets from Germany in which the valve caps at first would not screw on all the way. The gentle, repeating approach with a little lava soap on the threads eventually freed them up so that they could go all the way down.

[Paul S]

I would think that rather than use a hammer to apply even a light, controled blow, a leather strap wrench would be much more preferable. I work with fragile ebonite ear caps, frozen brass screws and soft nuts on late 1800s telephones and I always use a strap wrench to free them safely without damage or scarring.

The leather strap leaves no marks in the soft brass, applies torque along the whole outside diameter of the object equally and is a relatively inexpensive and simple tool to use. They are handy to have around for all sorts of "sticky" situations as well.


around a cornet mouthpiece for size comparison

[Dean E]

Also, what's the best way to get the caps off the bottom when they're really stuck? I havent been able to get them off at all.

To free the bottom caps, soak them overnight with Liquid Wrench, WD40, Breakfree, or one of the other gun cleaners.

They should unscrew by hand or with a small strap wrench. If not, and you don't mind tiny tool marks in the cap center holes, then, from the bottom, use a large Easy Out and a long tap wrench.

If you don't have an Easy Out and tap wrench, take it to a repair shop.

[Rick F]

I recommend you get a kitchen tool called the "Zyliss Strong Boy". It works great on valve caps and has a rubber area to protect against scratching. The band or strap is now made of rubber and is tightened by turning the bottom handle. I've used it with much success. It's fairly narrow so fits in tight spots like valve caps. Cost is $12.56.



Tuba-Euphonium Store
http://astore.amazon.com/tubaeuphonium- ... B002O3Y7I2

[Lew]

I have one of those, but it tends to slip on really tight caps, like those on the 100+ year old tubas that I have purchased. Letting a little WD-40 sit on the threads for a little while works well, and a leather or rubber strap wrench seems to have a little more torque when needed.

[Rick Denney]

I think this method puts less stress on the metal than hammering; perhaps someone will explain how I am wrong.

Art, it seems that most of the time my valve caps are not stuck because of being torqued down too tightly (despite my nickname when I was a mechanic in college--Captain Torque). It seems as though they usually get stuck because of corrosion. A small rawhide hammer will break loose the corrosion directly (corrosion is more brittle than the base metal). If the corrosion is really bad, pliers might have a better chance of galling the metal.

Also, on most tubas these days, it's not easy to approach the bottom valve cap with a pair of pliers as you describe at the necessary straight and secure angle. Thus, pliers seem riskier to me than the rawhide hammer. That's also the problem with most strap wrenches and other tools of that sort. They would all be completely ineffective on all three of my piston tubas because the bottom caps are buried in the tubing.

Rick "who would rather let the tool do the work and avoid muscling things too much" Denney

[sticky_valve]

I took my recently acquired horn to the local repairman to do some minor solder work and thought while it was there get him to free the bottom valve caps (correctly).

When I collected my horn he advised he did not have the correct size tool to complete the job.

I have not yet tried to soak in WD40, I'll start this process tonight. However the repairman also sugested securing a metal hose clamp around the cap and then taping on the screw to free them up.

Has anyone tried this succesfully without causing damage? Can anyone forsee something I or the repaiman has not considered if the process was applied?

I'm hoping the WD40 will do the trick, just thinking ahead if it does not.

[Dan Schultz]

..... The gentle, repeating approach with a little lava soap on the threads eventually freed them up so that they could go all the way down.

Be careful with the 'lava soap approach'. That stuff contains pumice and pumice will imbed in brass... and can cause more trouble than you started with. There are some very good garnet lapping powders that will not imbed in brass and work very well for lapping pistons, slides, and beat-up threads.

[pjv]

I didn't read all the posts (sorry, my valves aren't stuck) so pardon me if I'm repeating someone else, but;

don't use pliers. You can warp the valve casings.

Once they're unstuck they can always stick again. I put a drop of valve oil on the threads (possibly a useless endeavor) and I always loosen up all valve caps (top & bottom) on a regular basis.

Good luck.

[Alex C]

All you need to do is break the corrosion on the threads. You can tap the bottom caps with a leather hammer (NEVER use a metal hammer) quite sharply on the outer edge striking straight "down." Do not strike "in" toward the casing if using force, a miss may dent the casing.

If the bottom of the valves is buried in the tubing, use a wooden dowel rod on the outer edge and strike it with the hammer. You don't have to strike the valve caps in the direction of the turn (but it helps). All you are doing is breaking up corrosion.

If none of that doesn't works (and it always has for me) take it to a repairman.

Lastly, once you are finished with brushes on the casings and valves, clean and grease the threads.