[TPIN] BACH 37

[John Miller]

D. Michael McIntyre wrote:
> I'll put in a me too on this one.  It really could work.  Clean out the 
> casings really well with Simple Green like Nanette recommends, BiNaK the 
> sucker, and see if it doesn't straighten up.  It's less than $10 to try, so 
> if it doesn't work, it was still worth a shot.
>   
What Michael and Steve said, and just as a reminder, lapping ought to be
the last thing tried, as it removes metal, and puts "thousands of miles"
of wear on the valves.  Regrettably, some folks -- even repair persons
who should know better -- jump directly to lapping, because it's easy
and effective.  An unfortunate side-effect is that it makes the valves
leakier.  Once valves are fitted and moving smoothly, lapping should
never be done, except after physical damage where a valve cylinder is
deformed.  Corrosion can be removed in other, less destructive ways, and
metal deposition is a whole different (and relatively rare) situation
which probably requires a complete overhaul, instead. 

-- 
John Miller
Peachtree Wind Ensemble