Fountain Pen Sac Size Guide For Repairers

[crofton99]

In response to a dearth of requests, I have just created a Fountain Pen Sac Size Guide for Repairers.

I write science papers and have always wanted to publish something with the phrase 'veritable dearth of information'. Seems editors never think this is a good idea and it gets redlined out ....

[tenney]

Thank you, Richard. What about some brands not found in that chart (oh, Swan, Conway Stewart, Unic, Wyvern, etc.)? If one's learning to re-sac their own pens, do you suggest just getting a set of sacs and then keep trying until it won't fit and then go down one size?

[wasnhas]

Thank you !

[Cognaticrotty]

What sac would be needed for a mabie Todd blackbird? I'll post pix when it gets here

[hbquikcomjamesl]

A #16 straight sac is indeed a match for a Wearever Pennant. As is a 54mm J-bar (but note that the original J-bar has a ridge where modern ones have a channel, which means you'll have a slightly floppy lever).

[rpk1204]

Hey, anyone happen to know the correct sac size for a Salz Brothers Peter Pan pen? Just restored one and need a sac. I suppose I could just do it the old fashioned way and get the ruler out..... Much smaller than an Arnold mini which takes a 14,so guessing it may be as small as a 10. When I flushed the nib and feed I was amazed at how much ink came out. Thanks for any help! The pen actually turned out pretty well and cute!

[sumgaikid]

From the responses so far, it seems reports of its dearth have been greatly exaggerated...

 

--Daniel

 

 

No problem in my mind which sac to use; I just love this quote!

 

John

Edited September 11, 2013 by sumgaikid

[LWJ2]

Thank you, kind sir. It was both generous and thoughtful of you to publish this.

 

Leon Jester

Roanoke, VA

[S-K]

It seems the link not working now..

[BookCat]

Does anyone know which sac size (not length) I'll need to re-sac a Conway Stewart Dinkie 550?

 

Thanks Lots,

Catherine

[Steven Mellemans]

This is quite a list. I'm impressed!

Do I understand correctly that these sizes are not the original but your proposal for a best fit?

 

Regards,

Steven

[PenjaminFranklin]

This has proven to be quite helpful to me. Thank you, Sir.

 

Mike

[corgicoupe]

I just acquired a Parker Parkette the with a 0.30" nipple. The Esterbrook #16 was a tight fit, so I guessed at #17. Was this a good guess? It seemed to work.

Edited November 15, 2016 by corgicoupe

[AL01]

In response to a dearth of requests, I have just created a Fountain Pen Sac Size Guide for Repairers.

 

Thank you for the useful guide!!!

 

Now I can repair the most expensive pen in the world.....

 

(It's totally NOT a Wearever Pennant.)

 

Thanks Again!

[jcp1st]

What size sac would be appropriate for the modern Conklin Mark Twain Crescent Filler?

[Ron Z]

I you are not sure what sac size to use, you can measure the size of the sac nipple. General sells a dial caliper with a scale graduated in 64ths of an inch. A nipple diameter of say 18/64 would use a #18 sac, 20/64 would be use a #20 sac etc. If you need to, you can go down a size, from 18 to 17 for instance, but not up because the sac would be loose on the sac nipple and would not be sealed or hold properly even with shellac.

[MYU]

I was previously trying to measure section nipple diameter by eyeballing it with a ruler. And I think that method inherently ends up with a slightly smaller value. As a result, when I bought some sacs recently, they turned out to be on the small side... enough that I had to shift my intended pens for installation.

 

Thankfully I discovered that I do have a digital caliper! And I confirmed that my previous measurements were smaller than actual.

 

I have a question though. Two pens I measured came out as 7.6 and 8.6 mm in diameter. What sac sizes should I use for them?

7.6 --> #19 or #20 ?

8.6 --> #21 or #22 ?

Edited May 6, 2017 by MYU

[KathleenBlair]

In response to a dearth of requests, I have just created a Fountain Pen Sac Size Guide for Repairers.

Dear Richard,

 

I've read your Reference section about sac replacements here

http://www.richardspens.com/ref/repair/sacs.htm

 

but I don't see any mention of what kind of replacement sac to use for my particular pen. I found your reference section on the Fountain Pen Network Forums here https://www.fountainpennetwork.com/forum/topic/219105-fountain-pen-sac-size-guide-for-repairers/

 

My pen is a Pato fountain pen, and the sac was kind of crumbly and dried and seemed to be made of some kind of rubber - pictures are here https://imgur.com/a/hoqNPOm

 

I think I'm also going to have to replace the nib - it says Durium 4 but the left tip of the nib is missing.

 

Can you make a suggestion for a sac replacement ?

 

Thanks

 

Kathleen

[Ron Z]

Having retired, Richard is rarely on FPN these days.

 

This is not one of the major brands, so is not likely to show up in any list of pens. Pens that size usually use a sac in the 16-18 range, so that would be a safe guess. Lots of folks say, "Just use the sac that fits," but that assumes that you have a supply of sacs, and not all amateurs do. If you want to be "precise", and don't want to buy a bunch of sacs, you can measure the sac nipple.

 

Sacs are sized in 64ths of an inch i.e. a #16 sac is 16/64 OD. It will stretch and fit onto the sac nipple. Home Depot still sells a dial caliper by General with a scale in 64ths of an inch. Both Home Depot, Lowes and Harbor Freight sell a digital fractional caliper that would work.

 

Whatever size you use, be sure to secure it with shellac, often sold as sac cement.

[Richard]

As it happens, Richard is here today.

 

My sac size guide also includes instructions for finding the right size sac for any vintage pen. I will quote those instructions here:

 

"For pens not listed, choose the largest sac that drops freely into the barrel with the pressure bar in place."

 

By following these instructions, you will get a sac that fits well, does not bind, and gives you a little breathing room between the sac and the barrel, thereby reducing the tendency for ink to bleed out of the pen due to heat from your hand.

 

As for your Durium nib, replacement is the only alternative. For the reason, I'll quote from my Glossopedia:

 

DURIUM. Term imprinted on untipped nibs used by third-tier manufacturers during the 1930s and 1940s, an exotic-sounding marketing name for ordinary stainless steel. Some untipped nibs were even imprinted durium tipped, a designation intended to deceive purchasers by its resemblance to iridium tipped. See also iridium, steel.

Edited February 17, 2019 by Richard