I'm changing colors in my cheap Wing Sung, and the PR Midnight Blues has stained the ink sack. I'm filling with 10% solution of Pearson's Ammonia household cleaner (non-sudsing) and I'm wondering how long it might need to soak, and if I should not soak too long.

I'm wondering if the ink partially dried out in the pen (poor cap or seal?) but it was not to the extent of crusting over. I had no trouble rinsing out the nib and converter.

--John

Don't let it sit too long. Ammonia's a chemical with potential to affect various plastic and rubber parts over time.

I had an ammonia experiment blow up in my face in college chemistry. Hot broken glass everywhere. It can be powerful stuff!

Were you using 30% ammonium hydroxide?

A stained sac isn't a problem, unless you want a clear sac on the pen. The stain gets into the sac & stays there. If it does leech out (very unlikely in my experience), it'll only be so slowly that it won't affect the current colour.

I'm a bit niggled myself with a P17 Lady, it had a clear sac and chalkmark when I put in Diamine Sapphire Blue. It now looks heavily used - in fact the sac is so stained it's almost impossible to check on the ink level. The chalk mark is still there, and now looks out of place. When I put different ink in, there was no discolouration of the ink from the Sapphire Blue though.

Regards

Richard.