Most of the time, room temperature water is sufficient for cleaning a fountain pen. However, if your pen has a lot of dried ink in it or you want to change your ink color or ink brand, a good soaking in a cleaning solution can help. This recipe was created by an experienced fountain pen user. A word of caution: we do not recommend using this formula with old or vintage fountain pens because ammonia or even water can cause damage to them. This solution should be safe for most modern fountain pens, but again, please use caution if your pen is made from some specialty material.
Here’s a formula for a fountain pen cleaning solution that you can make at home:
1 part household ammonia (no stronger than a 10% ammonia solution)
2 parts water
Drop or 2 of mild dish detergent such as Dawn or Joy
Store the solution in a wide-mouthed glass jar large enough to immerse the parts of a pen.
Take apart your fountain pen and soak the feed and nib in the cleaning solution for several hours. Most of the time it is not necessary to soak the barrel or the cap. Remove the feed and nib from the cleaning solution and rinse with room temperature tap water until water runs clear. Blot with a clean, lint-free cloth and allow to dry overnight.
This solution can be used several times. It is a bit smelly! Follow all warnings on the household ammonia container and do not mix with chlorine bleach.
Others have had success soaking & cleaning fountain pen feeds and nibs in household ammonia straight from the bottle. They warn that before doing this be sure that the household ammonia has no more than 10% ammonia in the solution! A stronger solution may damage your pens.