Step 1: Disassemble the Pen
First, uncap the pen and remove the nib section (also referred to as the grip section or just "the section") from the barrel of the pen. This is usually done by unscrewing the pen where the nib section meets the barrel.
If your fountain pen uses a cartridge or converter, remove it from the nib section. To save the ink and use it again after cleaning the pen, you can use a piece of tape to seal the opening of the cartridge or converter to keep it from drying out.
Step 2: Rinse
Hold the nib section under running water for a few seconds. This will wash off any easily removable ink and make the next step go much faster.
Use only cold or room-temperature water when cleaning a fountain pen. Hot water may warp or damage some components.
Step 3: Soak
Prepare a cup of clean water and place the nib section in it to soak. Replace the water when it becomes saturated with ink. Repeat until the water remains clean for at least an hour. Note that some inks—especially ones that have high saturation or water resistance—can take longer than others to clean out of a pen.
Regular tap water generally works fine, but distilled water may be safer if your tap water has a high mineral content.
Step 4: Dry
Remove the nib section from the water and let it dry for 12–24 hours. For best results, leave it sitting nib-down in a small cup with the nib wrapped in a soft, smooth cloth or paper towel to help draw the water out of the nib section.
Step 5: Reassemble
Once the nib section is dry, install the cartridge or converter if the pen uses one, and screw the nib section back into the barrel.