It is not easy to remove the stains of a iron gall ink with water. However, You may set your mind at ease. You can easily clean your fountain pen that stain with iron gall ink using ascorbic acid (vitamin C) solution.
How to Clean Iron Gall Ink Stains
|Above image is that fountain pen with iron gall ink stains.|
|Above image is after dipping in 1% of ascorbic acid water solution for 20 min.|
|Stains of iron(III) ion with gallic acid is solubilized by reduction with ascorbic acid.|