Posted by Jay Bertolet on June 28, 2002 at 07:30:28:
In Reply to: First Valve Sticking posted by Brenda on June 27, 2002 at 22:19:26:
If you don't want to go to all the trouble of following Roger's good advice (it isn't a certainty that imbedded pumice is the cause of your problem) and you want to try something a little less difficult, try this:
It has been explained to me that when an instrument is new, or if the valves have just been chemically cleaned on a used instrument, there is a necessary break-in period for the valves. When you oil a valve and then push it up and down in the casing, there is a varnish that forms on the surface of the valve. Initially, this varnish (which is visible but sometimes not very) has a very rough texture. It will cause the valves to bind. Eventually, after about two weeks give or take, the rough parts of this varnish are sheared off by the valve action and the valve operates more smoothly. The solution? For the first two weeks you use the horn, oil the valves ALL the time. I mean, multiple times per day. Also, try your level best not to do anything that might clean the varnish off the valves like using any sort of polishing compound or chemical. Cleaning out the valve casing and wiping off the piston are okay, just don't use anything other than water and a rag or brush. Just oil the valves a lot and be patient. So far, this theory has been borne out in reality with my piston instruments. I Especially like Roger's suggestion of using Hetman's Light Piston Oil. This is what I use on my most problematic piston valves and it is a pretty good oil. If you specifically look for any valve oil that is designed for very tight valves, it might be the best fix for you. New instruments tend to have very low tolerances in the valves and the normal or heavier valve oils will make the problem worse. If you still have problems, you may need to follow Roger's advice and look to remove pumice deposits. You also might have to deal with having the valves lapped to create more looseness in the fit which will help as well. I would advise this step as a very last resort because removing metal from the valves will shorten their lifespan. Good luck to you!
My opinion for what it's worth...