In my continued attempt to remove ink staining (some kind of uber-permanent variety) from the inside of my Montegrappa Symphony, I've moved up to soaking in Ammonia. I don't really know what I'm doing though, so would appreciate some tips. Beyond any general guidance, I'd be grateful if you could help me with these specific points:
- I hear people talk about 10% ammonia. Is this 10% household ammonia solution, or 10% household ammonia to 90% water (as in about 1% actual ammonia)?
- How long would you say it's safe to soak?
- Is it worth me putting the pen and ammonia in an ultrasonic cleaner, in the hope of speeding up the cleaning and thus having the pen exposed to the ammonia for less long?