A few years ago I bought a Pilot Metropolitan fountain pen. It's decent, but the ink evaporates really quickly.
Last year I bought an inexpensive Platinum Preppy and it doesn't have this problem at all. No idea why the Pilot is so bad or if I can fix it, but it basically makes the pen useless to me because I do not write daily. Even if I did use it daily, the disappearing ink means I'd have more maintenance to deal with than I really want.
The other thing many people don't think about is paper quality. Fountain pen ink really soaks through many types of paper. It took me a while, but I finally found a yellow legal pad brand that is great with a fountain pen. Mintra canary premium legal pads are inexpensive and nice to write on.
For newcomers: if you get a pen that seals properly (so it won’t dry out), consider getting a fast-drying ink; you won’t end up with streaks across the paper and on your hands. I found Lamy T52 acceptable.
Last year I bought an inexpensive Platinum Preppy and it doesn't have this problem at all. No idea why the Pilot is so bad or if I can fix it, but it basically makes the pen useless to me because I do not write daily. Even if I did use it daily, the disappearing ink means I'd have more maintenance to deal with than I really want.
The other thing many people don't think about is paper quality. Fountain pen ink really soaks through many types of paper. It took me a while, but I finally found a yellow legal pad brand that is great with a fountain pen. Mintra canary premium legal pads are inexpensive and nice to write on.