The first thing to do is to clean the pen. Disassemble the business end of the pen by unscrewing the small collar into which the nib fits. You can then push the feed out of the collar from the rear, and the nib will come loose from the feed.
Put these parts and the gripping section to soak in a 1:10 solution of clear household ammonia in water, and soak overnight. Stir from time to time. This long soak is important because the collector, inside the section, is not readily removable, and you want to allow the solution time to work its way into the collector. When you fish the parts out, rinse them thoroughly, floss the nib slit with a piece of 0.002" (0.05 mm) sheet brass. Use the brass to floss the channels in the feed, too. Now reassemble, and use an ear syringe to force a lot of water through from the back end, to clean out the collector. Shake out the excess water, and try the pen.
