Sac for Faber Castell Osmia 223 ?

[Pterodactylus]

Hi All,

My Faber Castell Osmia 223 needs a new sac.

https://live.staticflickr.com/65535/50611417497_d7c3d8802c_o.jpg (https://flic.kr/p/2k7mK9v)Faber Castell Osmia 223 - F (https://flic.kr/p/2k7mK9v) by Ptero Ptero (https://www.flickr.com/photos/160419091@N04/), auf Flickr

Faber Castell Osmia 223 - F


Currently it had a straight sac installed.

Peg width is 6mm so I would choose a size 15 as replacement.

But the filling volume of this push button filler was always quite poor so I thought wouldn´t it be an option (or even better) to install a necked or necked and tapered sac as replacement?
As I read often that Necked sacs are better for push button fillers.

Pendragons offers the following sacs (beside the straight ones):


Size 15 x 1 7/8 Necked
Size 15 x 2 1/8 Necked
Size 15 x 2 1/4 Necked and Tapered


Can you please advise me what size to choose and if you also would try a necked one instead of a straight one?

And is my assumption correct that also for necked sacs the size stands for the narrow part (just like for the straight ones)?

And what exactly is the second number?
Does it mean that it widens e.g. for (1 7/8)/64 of an inch?
How is this for necked and tapered ones?

Thanks :)

[Seattleite]

I think that you are mostly correct. The second number is the length in inches of the numbered girth portion, e.g. 15/64ths x 1 7/8th inches. I think that the 64ths coefficient only applies to the #size, not the length. I guess that diameter and length of the neck is not defined. Way way back when I ordered necked and tapered sacs, the size was paired with the specific pen models that it fit, so I never paid attention to size. The Pen Sac Company still has a reference, but mostly for American pens.

When you figure shipping costs, maybe it makes sense to get at least a couple of the sizes that seem close. May take a couple of tries to get it right.

Is that a 50s vintage Osmia? Looks like it is in fabulous condition.

Bob

[whych]

Have you asked Pendragons what size they recommend? Although FC/Osmia is a 'niche' brand in UK, he may well have done one in the past.

I should imagine the sac should be a similar size to the old Parker Duofold button fillers.

[Pterodactylus]

Thanks for your responses.

Yes it is from the 50s and in excellent condition.
I really enjoy writing with this little pen, the pen is marked as F but the semi flex nib writes very fine, almost a needle point (but still feels excellent).

I read the references lists, but they do not include Osmia / FC pens.
I doubt that they have additional compatibility infos, as they mention on their site they keep the lists updated when new info become available.

Do anybody has experiences with necked vs straight sacs?
Is there a noticeable difference for button fillers (as some posts claim)?

[whych]

The vintage German nibs are a grade or so finer than the modern nibs. All the nibs of that era write finer than one would expect from the modern widths, So a vintage fine is probably closer to a modern EF at least.

At the time your pen was made, Osmia was producing nibs for most of the major brands.
Like the Pelikans of the time, flex in the nib would have been common. People all knew how to write with a FP so rarely pressed too hard.
If you needed to press hard, like for carbon copies, you bought a 'D' nib (the Americans called theirs a manifold nib).

What I meant by 'asked pendragons' was 'have you sent him an email and asked him?' They are usually good at replying.

If it was my pen, I wouldn't worry too much about using a necked sac, As long as you get the length right and don't twist the sac on the pressure bar when you put the barrel back, the sac should hold enough ink and the bit of extra lenght you may get from the tapered sac should be minimal.
If you look at the shape of the Parker Duofolds, it is similar to the Osmia with the taper at the end and they all use straight sacs.

The other person you can ask is Christof (username both here and on FPN) Chances are he has had some experience of Osmia button fillers.

Sorry I can't be of more help, but all my vintage German pens are piston fillers.

[jos]

Can you please advise me what size to choose and if you also would try a necked one instead of a straight one?
And is my assumption correct that also for necked sacs the size stands for the narrow part (just like for the straight ones)?
And what exactly is the second number?
Does it mean that it widens e.g. for (1 7/8)/64 of an inch?
How is this for necked and tapered ones?
Thanks :)

A "15 x 1 7/8" sac has an outer diameter of 15/64 inches (measured at the open end) and a length of 1 7/8 inches.

If you choose the necked sac, it is important to know the exact length of the sac in need (the neck prevents significant shortening of the sac). The original sac for this pen will not have been a necked one. The 223 is the middle size of this Osmia series (in between 222 and 224), risking that the necked sac is also too broad for the 223 barrel. So I would go for a simple straight sac that you can cut to the optimal length according to the available space inside the barrel.

[Pterodactylus]

https://live.staticflickr.com/65535/50808088331_2c34b43354_o.jpg (https://flic.kr/p/2kpJJwX)

(Faber Castell Osmia 223 - F ..... Colorverse Gravity Wave)

[Seattleite]

A job well done! If the internal dimensions in your pen point to a necked sac, why not!

Beautiful handwriting.

Bob