Air bubbles in converter

[greencobra]

I have a pen that picks up frothy air bubbles when the converter is filled. Obviously it picks up air somewhere but I can't figure this out. The converter screws in, the lips that fit on the nipple look good, no splits showing under a glass. The top of the converter at the screw knob seems secure onto the converter body. I've inserted this so deep into the ink I don't see where air would be introduced. But yet every time I remove it from the bottle the thing is filled with the frothy bubbles. I have to turn the nib/converter up, tap the converter with my finger and hope all the bubbles head up. I then turn the knob until a drop or two comes out the nib. The pen isn't 100% reliable, skipping at times, which I assume is associated with the air. Any ideas?

[ZeissIkon]

How tight is the converter on the cartridge fang? If it's not pretty tight, you might have a leak at that joint, which could cause the froth. That's the only place a leak can really occur behind the front end of the section.

 

The skipping can happen with a converter that's too small in diameter, allowing surface tension to support the ink column above air bubbles introduced from the feed -- the ink will seem to "stick" in the back of the converter instead of falling to the section end. The only solution for this latter problem (assuming flushing with dish soap in water doesn't improve it) is to use a larger diameter converter.

[Ondina]

I've always thought some air is necessary inside a converter for it to work properly. Isn't it this the reason one should turn the knob and drop a few ink drops and then turn it up again so the air helps the ink flow?

[scutterdav]

I've gotten bubbles in a converter like that before when I didn't have the nib in the ink enough. With some pens you just have to put the tip in the ink, but with other you have to submerge the entire nib up to the section in the ink for it to fill properly.

 

As for skipping, it's possible that it's due to the bubbles, but it's also possible that it's completely unrelated and could be a number of other reason.

[Mrsal]

I've always thought some air is necessary inside a converter for it to work properly. Isn't it this the reason one should turn the knob and drop a few ink drops and then turn it up again so the air helps the ink flow?

 

yes, this is true. you need to drop about 3-4 drops of ink back into the bottle then suck up some air so that the converter works properly.

[ZeissIkon]

I've always thought some air is necessary inside a converter for it to work properly. Isn't it this the reason one should turn the knob and drop a few ink drops and then turn it up again so the air helps the ink flow?

 

My understanding was that this puts the feed closer to steady state (by drawing air into the converter, you also draw excess ink from the filling out of the feed) than it would be if you just filled, wiped, and started writing.

 

On the opposite side of this, though, lever fillers are harder to do this with (manipulating the lever subtly enough to expel just a couple drops of ink is slightly tricky), and my Esterbrook (with external feed fins) seems happy enough if I just soak up the worst of the excess ink with the same paper towel I use to wipe the nib. In terms of the ink column, capillarity vs. gravity vs. pressure, it shouldn't matter if there's a tiny bubble in the converter or an absolutely complete fill (and I have very few pens that will fill 100% anyway, at least without considerable manipulation); the same balance of ink pressure against vacuum will establish itself pretty much instantly when you turn the pen nib down to write.

[Ondina]

I was just mentioning because air bubbles seem inherent to converters to me. But they usually go away after a few minutes. And I'm reluctant to accept skipping has anything to do with them. They are a good number of other reasons that cause it. But the air in a converter?

[ZeissIkon]

I was just mentioning because air bubbles seem inherent to converters to me. But they usually go away after a few minutes. And I'm reluctant to accept skipping has anything to do with them. They are a good number of other reasons that cause it. But the air in a converter?

 

The only connection between air in a converter and skipping would be in the scenario I outlined previously. As long as ink can get to the feed, the pen should write consistently, unless there's a problem with the feed, nib, etc., and a converter that's correctly designed (dimensions and materials) should allow ink to bypass bubbles and reach the feed. A partially clogged feed may cause the nib to run dry and skip; a nib that's too far from the feed may skip due to broken capillary path if too much pressure is applied, etc.

[aldi]

I have a pen that picks up frothy air bubbles when the converter is filled. Obviously it picks up air somewhere but I can't figure this out. The converter screws in, the lips that fit on the nipple look good, no splits showing under a glass. The top of the converter at the screw knob seems secure onto the converter body. I've inserted this so deep into the ink I don't see where air would be introduced. But yet every time I remove it from the bottle the thing is filled with the frothy bubbles. I have to turn the nib/converter up, tap the converter with my finger and hope all the bubbles head up. I then turn the knob until a drop or two comes out the nib. The pen isn't 100% reliable, skipping at times, which I assume is associated with the air. Any ideas?

 

I had the same problem with Visconti and Lamy converters. The ink doesn't flow due to capillarity efect (converter diameter is too small so ink "sticks"). I solved this problem by inserting a very small metal or plastic ball into the converter (1 - 2 mm in diameter). Now ink flows in the converter when I turn or shake the pen. If you want a "quality" plastic ball, some Sheaffer cartridges come with it. I hope this helps.

 

Regards