| Main tuning slide? Old Cornet? Have you tried cleaning it up with Brasso yet? If not, do so. You could be in for a pleasant surprise. The thing with many of the older horns is that the slide doesn't need "lapping" so much as it needs the crud and corrosion taken off. Go easy with the "elbow grease" and defiitely don't clean it beyond where the "marks, spots and stains" disappear. Stop frequently, regrease it, and try to see if you've taken enough off to allow it to move smoothly.
You may find that either of the tubes is somewhat "out of round" also... a repairman is generally required to run a sizing ball through it and get it back to "circular". Pretty inexpensive work. |