Cleaning ink

So I am new to fountain pens and have some questions.

First I bought a Pilot Varsity and Platinum Preppy. I have read that the varsity can be refilled and the preppy made to an eye dropper pen. My question is when switching inks do you just rinse it in the sink? Are the inks water soluble?

Also a similar question is I have an older fountain pen from my father. It probably hasn't been written with in years. The tip is all like dried up ink and it doesn't write. How do you clean it out? Can I use a wet rag?

Thank you.

For switching inks, just rinse out all parts containing/using ink under lukewarm water until it runs clean. After that, let it thoroughly dry (preferably overnight) then reload with your new ink.

For your fathers old pen, flush warm soapy water through it to break up the old dried ink, then use the above steps.

There are a couple of videos on the Goulet Pens site that may help. This one is helpful, but this other one shows a useful fast method

Before advising on your father's old pen, it might help to know what kind of filling system it has. If it uses cartridges and/or a converter then the method in the second video may be helpful. If it has a built in filling system of some sort, then depending on what it is, you may want to use different methods, and in a worst case it may need more than just a cleaning. But let us know.

I use a couple of old cups: one empty and one with clean water. Use the clean water to wash the pen and the empty cup to rinse. When I'm done, I usually dilute the inky water with more clean water before dumping it into the sink, just in case. If I stained the sink, I'm pretty sure my wife would make the rest of my day very bad!

get a nose/ear bulb for babies and cut the tip down a bit if needed. They work well to flush out most pens and blowing air through helps to dry faster.