How to remove a 51 aerometric breather tube

[mitto]

Even if not snapped off flush with the end of the feed, the croded tube would break off from the end of the feed if in case you try to pull it out without using heat.

Edited April 16, 2018 by mitto

[MarcoA63]

the article written in 2009 by kirchh is not available anymore in 2022. Is it possible to find it somewhere else? thank you

[Ron Z]

The short answer about breather tubes.

 

Breather tubes allow for a more complete fill of a pen.  Eversharp used them in their Skylines, and they pop up on some other brands.

 

Pens with breather tubes fill incrementally.  On Vacumatic filler pens, each cycle of the pump pushes air out the breather tube, and ink is drawn into the pen through the breather tube when the pump is released, over the top of the breather tube to be retained in the barrel.  Because the ink channels are smaller than the ID of the breather tube,  there is resistance to ink flowing out through the feed, so air is pushed out the next time the pump is pushed down.  The cycle is repeated with each cycle  until the ink is at or a little over the top of the breather tube.  The last time the pump is pushed down, the pen is removed from the ink so that air is pulled in, clearing the excess ink out of the breather tube and feed.  A 51 in particular will tend to flood if you don't do this when filling a pen.

 

When to replace?  On Vacumatics, only when the breather tube breaks.  The replacement should be short so that it clears the end of the diaphragm when the pump is fully depressed.  I usually find them to be about 3/16" - 1/4" at most.  On aerometric 51 pens, they should be replaced if snapped off or broken anywhere along its length, or if the breather tube appears to be corroded.

[es9]

Is there any reason why the original silver tubes are functionally better than the stainless replacements? 

[Ron Z]

Not really.  I don't change them unless I need to though.  David Nishimura's work well.  I've made my own, but finding the right size tubing can be interesting, and then you have to drill the hole.