6 replies to this topic

[gweddig]

Quick Question:
Striped Duofold with 3 part button filling mechanism, date code is .2. (1942, 2nd Quarter?)

The feed has a breather tube in it, was this common on button fillers? How long should it be? The one I have here is broken and only extended a 1/4" above the nipple. Should it really extend up to the other end of the sac, like in Skylines?

Is this color a good candidate for a silicone sac?

Thanks in advance,

--greg

Edited to add that I found a discussion about this at the other place:
http://www.fountainp...-button-filler/

Edited by gweddig, 08 May 2015 - 03:21 AM.

[John Danza]

Those are fake breather tubes. I have the same thing in my Geometric Duofold. I'm not quite sure why they were put in the pens, as they don't do anything with a button filler.

 

I usually default everything to a silicone sac, so you could certainly use one here.

[entertainment]

Although the filling system of an aerometric P51 with a metal sac guard and a pvc sac may make it look radically different from this duofold with a button filler and a rubber sac, both pens have sacs and pressure bars that work in essentially the same way.  The sac is compressed which creates a vacuum that pulls ink into the pen.  So why wouldn't a breather tube enable the sac of the Duofold to fill more fully with ink with multiple compressions of the sac?

 

John

[Ron Z]

Although the filling system of an aerometric P51 with a metal sac guard and a pvc sac may make it look radically different from this duofold with a button filler and a rubber sac, both pens have sacs and pressure bars that work in essentially the same way.  The sac is compressed which creates a vacuum that pulls ink into the pen.  So why wouldn't a breather tube enable the sac of the Duofold to fill more fully with ink with multiple compressions of the sac?

 

John

 

Because while the breather tube is there, and it's stuck into a hole in the end of the feed, there isn't a hole through the top of the feed under the nib.  No way for the ink to get through.  It really is non-functional, and I suspect just for looks.  Pen companies were not above deception.

 

re. silicone sacs.  i.e. the ones sold by David Nishimura.  There are issues with gas permeability.  Not all gasses get through the wall of the sac, but helium is pretty darn small.  I've had to re-do a number of pens in which the true silicone sacs were used because they ooze ink.  

 

Take a look at this article for more discussion.

[Procyon]

There is no reason a breather tube wouldn't work in a button-filler, if the breather tube had the proper pathway to the outside.  A button filler differs from a lever filler only in the way the sac gets compressed.  And it's air that flows through the tube, not ink.  This system works fine in the Skyline, although it is the only lever filler I know of that has a breather tube (which means you can use the lever several times to get more ink in the sac).

[entertainment]

Thank you for the very informative replies.  I guess I just could not imagine that a pen manufacturer would drill a hole in the feed and add a piece of tubing unless it had a function, especially if the tube is not even visible!

 

John

[kernando]

The non-breather tubes that are just for looks are visible, before filling, in pens with clear sections.