1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Parker 61 fountain pen

  1. Jun 29, 2009 #1
    this is a unique fountain pen from the 60s in that you don't squeeze anything to get ink into it. you just dip the solid one piece 'cartridge' into the ink and it fills, presumably through capillary action - i don't know what's inside, but i doubt if it is a sponge to have lasted all these years.

    now if i keep the pen rightside up (the way you'd carry it on the clip in your pocket), i can write with it immediately. if i keep it upside down, no ink makes it to the nib despite the seeming gravitational advantage.

    if the instrument works on capillary action, the meniscus needs to be concave up in order for the surface tension to cause the ink to flow upwards against gravity. if we turn the pen downwards, the same capillary action will presumably cause the ink to go in the other direction despite gravity.

    the only difficulty i'm having with the above reasoning is that when upsidedown

    1. the ink doesn't flow out of the other end or flow to the nib
    2. the full-weight of the ink is towards the nib, but doesn't make any progress to it

    what i'm wondering is whether when upsidedown, the shape of the meniscus is sufficiently altered at both ends (though i don't know if it is correct to call it a meniscus at the bottom) so that capillary action stops completely.

    if so, this would seem to suggest an asymmetry in the capillary tubes perhaps (may be they narrow with proximity to the nib?), so that ink goes only one way?

    ideas or explanations?

    in friendship,
  2. jcsd
  3. Jun 30, 2009 #2
    Why would there be any "gravitational advantage" to the flow of ink in an upside down pen?
  4. Jun 30, 2009 #3
    i meant just towards the nib, pallidin.
    presumably with an upside down pen, gravity would pull the ink towards the nib which it does for regular fountain pens and ball points (which don't write too well when the nib is pointing up).

    in friendship,
  5. Jun 30, 2009 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Doesn't "upside-down" mean the nib would be the uppermost part of the pen? Then gravity would pull ink downward, away from the nib.

    What am I missing?
  6. Jun 30, 2009 #5
    we just have a discrepancy regarding interpretation of orientation. let me rephrase it.

    if the nib is pointing down, i would think gravity would pull the ink towards the nib - which it doesn't seem to be succeeding in doing if we just leave the pen lying around with the nib pointing down.

    if the nib is pointing up, gravity would pull the ink away from the nib, but it seems the capillary action overcomes this drawback and the ink makes it into the nib anyway.

    in friendship,
  7. Jun 30, 2009 #6
    Not to beat a dead horse, but I think it's important for those posting questions to phrase their questions in a way that is commonly accepted.
    For example, the "normal" orientation of a pen is either horozontal(such as on a table), or vertical(such as in a pen-holder) whereas in that last case the nib points downward.

    Therefore, a normal vertical orientation of pen is that the nib points downward.
    Thus, an "upside-down" pen infers(to the general public) that the nib is at the top.

    You presented the exact opposite.

    This is why we were confused.
  8. Jun 30, 2009 #7
    I must say this, however, in your defense:
    There are some pens which has a removable cap around the nib. The cap sometimes has a clip, which puts the nib in an inverted position when clipped on a pocket!!
    Yet, other pens have a clip mechanism on the opposite end to keep the nib pointing down

    So, I understand your position. But my(and others) previous post still firmly stands.
  9. Jun 30, 2009 #8

    i agree with you and apologize for causing this confusion.

    i wrote
    "i keep the pen rightside up (the way you'd carry it on the clip in your pocket)"
    and it wasn't sufficiently clear especially since pens do have clips in various places though i have never seen a fountain pen that is carried nib downwards in a pocket - i wonder what the consequences of doing so might be for pens other than the parker 61, but i'm not going to try it.

    so if the orientation issue is clear now:

    1. when the nib points up, the ink flows to the nib.
    2. when the nib points down (for extended periods of time) the nib seems to dry up.

    are there any ideas as to why this might be happening?

    in friendship,
  10. Jun 30, 2009 #9
    No need to apologize. We are all here for learning and sharing!!!

    For 1 and 2 why could it not be said:
    1: when the nib points up(for extended periods of time) the nib seems to dry up.
    2: when the nib points down, the ink flows to the nib.
  11. Jun 30, 2009 #10
    well palladin, it's not that it couldn't be said, it's that it doesn't happen at least for this pen which i think works on capillary action. the exact opposite happens as i outlined.

    i think it could be the way you state it though for a squeeze or cartridge fountain pen and definitely for a ballpoint (though that's really a different story).

    in friendship,
  12. Jun 30, 2009 #11
    Sure you have. Like those pens which you have to twist in order to extend the nib.
    The clip(in this case) is always on the opposite end of the pen from the retractable nib, thus keeping the nib downwards while clipped.
  13. Jun 30, 2009 #12
    Hmmm. Maybe I am unfamiliar with your specific type of pen.
    If so, my mistake!
  14. Jun 30, 2009 #13
    The original reason as to why pens were inverted(with the nib up) had nothing to do with promoting ink flow for writing, rather, had everything to do with helping to prevent ink-leakage onto a garment.
    Last edited: Jun 30, 2009
  15. Jun 30, 2009 #14
    In fact, ink flow is never promoted in an inverse capillary situation. It is reduced.
  16. Jun 30, 2009 #15
    I think I know what the root problem is now.
    Capillary action is not specifically dependent on gravity, but it is affected by it.

    Take two capillary-drawn ink pens. One with the nib pointed-up and the other pointed down.

    Over brief time, the one pointed-down will have an ink saturation in the nib far in excess of the one pointed-up, due solely to gravitational effects.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook