New information from Aaron [8Nov2012]:
For freeing up frozen screws, I use Evapo-Rust— which is easily available at auto parts stores. Although it reduces and dissolves rust, it doesn't restore the iron to the surface. So you don't get back the metal that was destroyed by rust on the threads on a screw. But it does remove the rust.
Another method for removing rust is to use an ultrasonic cleaner.
There are ultrasonic cleaners for jewlery for small parts. For whole clarinet joints I use one that I made. It's a bread pan with two tweeters mounted under the bottom. I drive the speakers/tweeters with a signal generator pumped into a 10 watt audio amp.
My thanks to Lars at MusicTrader.com for this information. Open the PDF attached below.
Ivan adds this:
Frozen screws --- heat area and allow to cool (soldering iron) -- apply a drop of Coca-Cola to the screw head. Heat /cool/apply drop two or three times. Proceed with your PDFI can't wait to try that! Will Diet Coke work? What ingredient causes this to work?
NOTE: One needs to be careful about heating posts on a wood or any composite clarinet! There are at least three clarinets in the world that I have almost ruined by heating a post too much. It's too much when there is a little whisp of smoke coming up from a wooden clarinet! And on a plastic clarinet, the material very quickly goes soft before there is smoke! Incidentally, I happen to know that Ivan has been working on a metal clarinet. One could safely apply a lot of heat on one of those.
2nd NOTE: Coca-Cola didn't work for me. I wonder if that works better for larger bolts than it does for little clarinet hinge screws.
More information from Ivan:
A small note of caution about some metal clarinets(like Harry Pedlers)
some metal clarinets had sub-components hard-soldered together, and then the final clarinet assembly was soft soldered with a very low melting point solder with silver in it (see the little islands in the pics of the clarinet I am restoring) - the ones that the pivot posts sit on). These were obviously held in a jig and sweated on at a final assembly.
Thanks for that great advice!
I used to keep a screw-top bottle of flat Coca-Cola in my engineering workshop for seized bolts etc -- think its the acidic chemicals in the coke that make it work. It works a lot better than WD-40.
I make my own screwdrivers when I have a stubborn screw (and I often put the driver in the slot and give it a tap (with backup).
The new diamond hones by Lansky are especially good for hand honing screwdrivers. It is most important to get a good fit in the slot,