P51 troubleshooting?

Discussion in 'The Nib' started by Isaac, Aug 1, 2012.

  1. Isaac

    Isaac Moderator Emeritus

    I need some help from you all. I have a P51 that was serviced within the last two years. Now, everytime I use this pen, pen flushes take over 10 minutes and even at that time it is not clean. The water coming out is still tinged with whatever ink I had in it. This is after ammonia/water flushes. I also notice that it doesnt seem to hold as much water or ink. The pen use to give about 10 drops when the vacumatic plunger was pushed, and now it lets out about 4 drops. It is pretty tiring trying to flush a pen for 10+ minutes.

    Just wanted to get some member's take on whats going on
  2. nemo

    nemo Moderator Emeritus

    Fact: the complicated collector has a lot of surface area and is difficult to clean completely.

    The use of highly saturated inks exacerbates the problem. I would do normal routine flushes with plain water too. When you fill do you push 6-10 pumps then it stops making bubbles?

    Hopefully our resident expert pops up soon with some answers for your capacity problem.
  3. Dave258

    Dave258 Moderator Emeritus

    I am sure Brian or Doug know best, but could your feed be clogged? The first 51 I bought was like that. I had to take it apart to get all of the gunked up old ink out of it. After that, it filled and cleaned great!

    EDIT: See, Doug posted while I was typing
  4. brianw

    brianw Moderator Emeritus

    Aero or Vac ?
  5. nemo

    nemo Moderator Emeritus


    Breather tube problems?
  6. brianw

    brianw Moderator Emeritus

    That would be my guess.
  7. Isaac

    Isaac Moderator Emeritus

    I thought it might be a problem, but the pen was serviced about 1.5 years ago, and does not get heavy use. Do you think I need to send it in to someone again to take a look at it? BTW, who do you recommend?
  8. brianw

    brianw Moderator Emeritus


    breather tube is fine. Looks like a std vac filler sac was used instead of the debutante filler. Probably twisted and didn't fit the plunger cup well. No shellac on the hood as well.

    A trip thru the sonic bath, Refit with the Deb filler, lubed and inserted. 8 plunges in water. 7 drops out first plunge, 6 second plunge, 2 last. Looks like it was the filler sac.

    Will let sit overnight and try again.
  9. Isaac

    Isaac Moderator Emeritus

    Can I use this opportunity for some teaching? What is a debutante filler? I am assuming it is a size of tube. What is the purpose of the shellac?

    Did you see how much ink was still inside the pen and hood. that was after two ammonia rinses.
  10. brianw

    brianw Moderator Emeritus

    Vacumatic diaphragms come in 3 different sizes

    [​IMG] Vacumatic Diaphragms.Left to RightDebutante/51's, Major/Std., Oversize/Maxima

    *courtesy of Woodbin.

    I believe the sac was the center one which is a tad bigger and can twist. When I pulled the plunger out the diaphragm pulled off the cup. This wouldn't have happened if it was the correct one.

    Shellac is used to seal threads. Without shellac on the plunger threads you will not get a tight seal, and without shellac on the hood, you could end. up with inky fingers and the hood will spin.

    Yes there was alot of residual ink in the collector. I think because of the diaphragm, not sealed well at the plunger, and no seal on the hood it became almost impossible to fully flush.
  11. $mustang.jpg

    I would reccomend a qualified aviation mechanic if your P51 is acting up.

    Sorry, I couldn't resist.
  12. brianw

    brianw Moderator Emeritus

    I sure wish I had one of those
  13. Dave258

    Dave258 Moderator Emeritus

    Brian, when I opened my 51 to clean it I did not shellac the hood threads back, I just used some silicone grease. I haven't experienced any problems with it yet, but do you think I should open it back up and shellac it?
  14. brianw

    brianw Moderator Emeritus

    No, no need if it is not bothering you. The shellac on the hood threads keep it from spinning and forms a seal. The silicone grease will form the seal and give somewhat a stop to keep from spinning. The old way was to use shellac.

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