What is a converter on a fountain pen?

How to clean a fountain pen?

• This is not a generic "How to clean a fountain pen" question. I have googled and have not found an answer. As far as i understand, to clean a fountain pen that has not been written with for a while(full cartridge left in pen for 3months+): this is what i have done soaked the nib in warm water (it is a cross fountain pen, yes the instruction manual recommends using warm water) for 1 hour used the converter to pump water in and out until it is clear. I have now switched ink to blue(previously black). Everytime i write something the first few lines are blue ink as it should be. After that though it starts writing with black ink again when the piston type converter is filled with blue ink. The only way to stop this is to make some blue come out by forcing the ink from the piston-surely this is not the solution? How do you clean this pen so that it writes normally? p.s. I have heard that you can use ammonia if it is very dirty-how safe is it? thanks in advance the pen should now be

• Answer:

  You may have to do several cleanings. The reason for using warm water is that you don't want any residue from cleaning products as well as not wanting certain chemicals from products having an adverse effect on the parts or next ink. If the black ink that was used previously wasn't water soluble or dried to the point of no return, then you may have to use the pen for black ink only. I couldn't tell you how ammonia will work or if it will cause any damage, but if you don't mind losing the pen all together, try anything. As a graphics engineer, I have lost more than one pen to leaving ink in it too long.