I was riding with a Wing Sung 3009 today (a pretty nice, super cheap piston filler BTW) when I noticed this gunk on the inside of the cap. I’m pretty sure that I filled the pen up with Noodler’s Air Corps Blue/Black a few months ago and then let the pen sit. It wrote pretty much right away.
But I noticed this brownish / tan / black residue on the inside of a cap, at the very bottom. I’m not sure if it was there before and I just didn’t notice, or if it is new. It almost looks like burned plastic? Or maybe it’s mold? But it seems like a weird place for mold to develop since there’s no ink there. Has anybody seen anything like this before? I’m probably going to throw the pen away anyway (it’s about $3.50) but was curious 🧐.
Looks like the screw is made of poor quality metal and it corroded
I’ve had this happen with cheap pens before, it’s definitely corrosion. It doesn’t harm the pen function but if you don’t like the look you can replace it with a nylon screw which won’t react to ink.
It looks like corroded metal, maybe?
Thanks everyone! I’ll rescue the pen now knowing that it’s not harmful!