This will be my first FP, so bear with me. What if I want to change ink types? Do I flush out a used cartridge and refill using a syringe? If so, what do I need to flush it with? Any recommendations on inks that typically work well with these nibs?
CalebKIt comes with a converter which is basically a refillable cartridge with a piston mechanism that siphons up the ink. You just need to dip the whole nib in an ink bottle and twist a part of the converter repeatedly to bring the ink up. Some people find this messy and just take out the converter and dip it directly into the bottle, or even refill it with a syringe as you mention. You can also just use cartridges as sometimes you don't have access to a bottle e.g. when travelling abroad.
CalebKyou have a couple of choices, you can just fill the pin with new ink by doing as others have suggested, dip in ink and suck up some more. Then you can watch your color fade from one to another. Be warned you will taint your ink with a little bit of the old ink. Or you can wash out the old ink under the sink by running the nib under water and filling and un-filling the converter till it is as clean as you like. Finally you can clean and fill just the converter.
CalebKYoutube is your friend. Search "flushing fountain pen" Unless you leave the ink for months and it dries up. water is just fine. Do not mess with dish soap or ammonia under normal circumstances. Personally I flush the pen when I change ink. In terms of mixing ink, be careful. Put a couple of drops together on a plate and see if it reacts.
Flush the pen. Safest.
mpechnerReact, what do you mean by react, I have never seen anything suggesting. I've written some explosive letters before, but now I could have even more fun?