@Chessie - There are various factors affecting how much use you can get out of a broad edge nib. (As
@Erica McPhee notes: pointed pen nibs don't last as long, because you stress them more by flexing).
The main three variables are:
How heavy your hand is. If you have a very heavy hand, you can splay/"spring" the nibs - especially very flexible, relatively delicate nibs like the Mitchells. A while ago you mentioned railroading with the Mitchells - that's a sign that you could lighten up the pressure.
What kind of ink you're using. Heavily lacquered sumi inks or acidic iron gall inks will corrode nibs pretty fast. When I use really heavily lacquered sumi inks (which are beautiful and shiny), I can see the bronze coating on the nib get stripped off after just a few hours.
How you're cleaning, drying, and storing your nibs. If you're using a straight holder (especially one with "universal/adjustable" internal metal flanges that grip the base of the nib), a little bit of water in there can cause a lot of corrosion and rust. I always take my nibs out of the holder, clean them thoroughly, wipe them dry, and store them in a separate tin to keep track of which nibs are in current use (I try to only have one or two active nibs of each size in use at one time). If I'm using sumi ink, gouache, metallics, or that Dr. Martin's bleed-proof white, I also give my nibs a whirl in the ultra-sonic bath at the end of the day.
A few other troubleshooting reminders:
* Sometimes you have to re-prep nibs if you get oils on them from your hands.
* When you remove a nib from a straight holder, pull it straight out. Try to avoid twisting it, because you can damage the alignment of the tines. (maybe that's how yours warped/bent?)
* You can sharpen broad edge nibs when they start to go dull (very much like a knife! hey, your knife sharpening skills might provide a great transition to nib tuning)
As a point of comparison, I often use a #2 or #1.5 Mitchell broad edge nib for years at a time before it goes bad. And even then, sometimes I give it a few passes over some 2400 grit sandpaper to tune it up and keep it going for another stretch. #2 and #1.5 are the ones I use most too. The more delicate #4, #5 and #6 nibs don't last quite as long, but I still use them for a year or two a time. And come to think of it, I can't even remember the last time I needed to bring out a new #2.5 or #3.
A few things allow for the preservation of my nibs: I have a very light hand from working with quills and brushes; I practice and layout with walnut ink and/or dye based fountain pen inks, which are very mild on nibs; I'm an absolute fanatic about cleaning and drying my equipment (seriously, not too long ago we had a discussion on the Forum about how to keep nibs from rusting, and everyone thought that I was a total weirdo for the lengths I go to clean and dry my nibs & holders every time I even pause for a little break).
* In contrast my students treat their nibs like garbage, and they hardly last through the semester.
Maybe if it's bothering you to go through $20-worth of nibs a year, try adjusting your pressure or cleaning regimen. But really, even though you're going through kind of a lot of nibs, do not worry that you're doing anything "wrong" as such, especially not at this stage of your development. You're pretty devoted to your ink sticks, so even if you clean and dry your nibs every day, they'll corrode faster. (Just a reminder that those ink sticks were originally designed with brushes in mind, not metal nibs).
--yours, K
