Fountain pens float effortlessly over the paper when everything is working as it should. That is one of the reasons why people who prefer fountain pens really like them. But they can be difficult when something is not as it should be. They can be scratchy. Ink flows poorly or not at all. And, they may put out too much ink, even in the form of a sudden blob of ink that runs over a document and onto clothing. These problems are not inherent to all fountain pens, but occur in pens needing a little tender care to keep them in sound working condition. Fortunately, all of this is much easier than a person would think.
The pen shown is from a Classic American kit sold by Woodcraft. The pen is reminiscent of a Parker Duofold from the late 1920's and early 1930's. The color pattern is very similar to one used on Duofold pens.
Step 1: Making it flow if dried out
A couple of Instructables advise soaking the nib and feeder (the section) in cool water for a day or so to remove old dried ink from the ink flow path or capillary system. Actually, a good flushing of the capillary system like this is advised every month. Another good practice is to add a little moisture to ink held in the nib and feeder that may be partially evaporated after a few days of non-use. Get a drop of water on your fingertip and touch it to the slit between the nib's tines. If the pen has been sitting unused for more than a few days, add two or three drops of water, Let it soak in. If you do not write with the pen immediately, the water can mix with the ink under the nib more thoroughly. Do this once a week and as necessary.
In more severe cases, as when ink has been left in a pen during several weeks of non-use, cup your hand under a faucet and fill it with water. Quickly dip the whole section into the water in your hand and remove it. Cap the pen and carry it in your pocket for an hour or so before using. If the writing is light in color, touch a facial tissue to the nib and feeder a few times to remove excess water or watery ink.
Fountain pens like to be used regularly. If you are not going to use a pen for a while, empty the ink from it and flush the pen with water until no discoloration from ink appears.
Do not mix inks from different manufacturers. They sometimes react with each other and form chunky, gelatinous material that clogs the ink passageways. Use fresh ink that has been tightly capped or fresh cartridges. Purists fill the air space in an ink bottle with an inert gas like nitrogen before putting the cap onto the bottle. They do this to keep the ink from oxidizing.