nostr:npub1p36pqtsd7as3a8qcqn2tmm3480acgqngaez0mvvta9vkwmcfzg2qduh2h0 I've used iron gall inks in my fountain pens for decades without an issue.. but yes I suspect that could be what caused an issue here simply due to the steel nib, and I think its fair to say with a reactive metal like steel you should be more cautious about the more aggressive inks that would be fine in a FP made with mor passive materials.

Speedballs are nice if you want dip pen. Not particularly helpful for a pen on the go though. Plus I prefer the convience of a FP as I can write anywhere in my home including on the couch or in bed.

Glass dip pens are nice but useless for most forms of calligraphy.