As some of you are aware, I have a few Esterbrook desk pens. (16-ish) I am particularly fond of the 444 Dipless models.
I decided to keep one filled with Diamine Registrar's on my desk for writing bills and such. I first restored (i.e. cleaned thoroughly and replaced the seal) the base, put a basic 1555 nib on it (no huge loss should it get ruined) and filled her up.
It worked great for several months. It was wonderful to be able to just reach over and pull out the pen, write a check and put it back in. And with the Registrar's ink my checks and envelops are quite safe from washing, water spills, rain, or whatever liquid may befall them.
Then Christmas came and I went out of town. And I wrote bills out of town so almost two months went by without using the pen. It dried up.
Today I went to clean it and I thought someone might be interested in the results.
The ink did stain the red plastic ring that goes inside of these bases to show level of ink. I was able to scrub it mostly off except in between the letters. I soaked the nib and soaked the rods in their little basket, but didn't bother taking them out for a thorough scrubbing. I rinsed it all over several times, dried them all, and filled it back up. It's now working wonderfully.
Probably in another couple of months I'll dissemble the base and clean the rods outs, making sure they're not sticking together.
With the exception of the staining of the red plastic ring, I had no issues even letting IG ink dry in the base. If I were going to change inks, I would have cleaned out the rod basket and cleaned off the rods carefully. But since I'm putting the same ink in, I didn't bother.
These 444's are so easy to restore, look great, and the design with the feeder rods I find preferable (and less likely to dry out) than the open well like the 407's.
So, fill up your 444, put a nice nib on the pen and use it. Keep one by the phone for messages, or grocery lists. Keep one on your desk for notes, bills, etc... And don't worry about IG inks rotting things out. Dipless pens don't have the same issues of clogging that you find in fountain pens, (because they don't need to flow from the reservoir to the nib), and Esterbrook's are built tough.