51 Vac Ink Capacity

[siamackz]

I have a 51 vac from 1946. It was restored by a respected pro. But when I fill it and eject the ink itnonly lets out 5 drops. Is this the capacity of the pen, or does mine need a resacing? I have tried every approach to filling it - pressing the plunger 5 times, 10 times, 1 time, etc. but its always 5 drops out, not more.

[Beechwood]

Very timely question.

 

I have just finished a 51 vac and tested it in the same way as yourself, I was expecting 7-10 drops of ink, only got 5.

 

Some people say that you get a little more if you press 15 -20 times but for the sake of a couple of drops of ink I am not sure it matters too much.

 

If it needed resaccing I dont think that you would even get 5.

[inkstainedruth]

I don't about 51 Vacs, but I had a Vac Shadow Wave that did not seem to take up all that much ink, even after being repaired. Took it back to the repairer (under warranty), who took the pen back apart, checked all the seals, etc. And the answer is -- that pen just doesn't hold a lot of ink. Apparently it has something to do with the breather tube -- the pen will only fill to the height of the end of the tube (if the pen is nib down, the top of the tube will be how far it sticks up in the barrel. So that might be your problem with the 51 Vac as well. Because even "Little Brownie" expels more than 5 drops of ink....

Ruth Morrisson aka inkstainedruth

[Offret]

So what's the official word on ink capacity of 51 Vacumatic vs. Aerometric? I always hear people saying the P51 Vacumatic holds more ink, but I read a couple experimental reports that that's not the case. Parkers own literature on the 51 Aerometric even states that it hold more ink than the Vacumatic version. Which is it?

[siamackz]

Thanks so much guys, this is a relief

[pajaro]

I would suppose that, if the Vac or Vac 51's breather tube is short, and mine are in both cases, it is because the diaphragm, when the filler rod is pressed, must still clear the breather tube, so there must be a clearance. I have restored my Vac and 51 Vacs, and the breather tube looks short, but the diaphragm gets pushed out toward it. There's only so much room in the pen.

[mitto]

My experiences is that ink capacity is almost the same. Well, there might be some negligible difference but not substiatial.

[Flounder]

The system isn't really designed to expel ink, so that's not a fantastic way to measure capacity. If I go really slowly on the downstroke, my vacumatic 51s will keep expelling ink droplets until about 1 ml, and still write afterwards.

[siamackz]

The system isn't really designed to expel ink, so that's not a fantastic way to measure capacity. If I go really slowly on the downstroke, my vacumatic 51s will keep expelling ink droplets until about 1 ml, and still write afterwards.

thats probably because the 51 feed holds so much ink ?

[Venemo]

Does the vacumatic 51 have a similar collector around the feed as the aerometric version?

[mitto]

Does the vacumatic 51 have a similar collector around the feed as the aerometric version?

Yes, the collector is the same in both vac and aero 51s.

[Flounder]

Yes, the collector is the same in both vac and aero 51s.

 

Similar but not quite the same - most aero collectors will have the later collectors with a spot weld to keep the weir vent open, while most vac collectors will have a little hole where their shim was sonicated out, aka 'fully serviced'

Edited December 19, 2017 by Flounder

[mitto]

Thank you. I think the context was the fin design and, thus, the ink capacity and not the minutiae.

[FarmBoy]

Best way to determine how much in a pen holds is to measure uptake from empty to full.

This can be done by using a volumetric flask to track ink taken up or by weighing a pen before and after filling and converting the difference in mass to a volume of ink.

[pajaro]

Some ink might dry up before you can write with it.

[oztech]

The ink capacity of a standard 51 Aero or Vac is about 1.5 mls. Todd is correct, the only way to tell if a 51 is filling to specification is by ink uptake NOT drops ejected. Parker supplied a special clear plastic "51 Capacity Gage" part number 10374. It held 1.5mls. The pen was inserted intothe gage full of water and the filler pumped or squeezed. If 1.5mls was drawn into the pen it "filled to spec"

Oztech