What Am I Mistaking - Sac Size Charts Binder Vs Fountainpensacs.com

[LargeSofa]

just getting going with re-sacing several newly acquired pens I bought and 1 that has sat in my drawer for 4+ years...

 

I saw two different sac size charts (both from reputable sources) and very complete.

 

Wondering my the differences and what I am reading wrong.

 

For example Parker Duofold Senior

 

http://fountainpensacs.com/parker.html

http://www.richardspens.com/?page=ref/repair/sacs.htm

 

thanks for the help.

[LargeSofa]

duh!

 

From Binder:

"For these reasons, the charts recommend sacs that are usually one or two sizes smaller than the sizes originally used; but in some cases, the difference can be as great as four sizes. In most cases, the smaller sac size vitiates the need for a necked sac; unless otherwise specified, all sacs listed here are straight sacs. For pens not listed, choose a sac that drops freely into the barrel with the pressure bar in place."

Edited September 11, 2014 by LargeSofa

[Procyon]

Edit: Well, LargeSofa beat me to an answer, and he is correct. Anyway, my response is still below.

 

Well, it appears to me that fountainpensacs has shown the original specs for the pen. Often those are very specialized necked sacs. Richard has probably given his, much more practical, recommendations for restoring pens. Richard mostly uses straight sacs - so he can keep a more reasonable inventory on hand.

 

The original spec sacs try to maximize ink capacity, which was a big deal, back in the day. To the owner of a valuable restored vintage pen, this is probably not so important. In addition, pens often function better with slightly smaller sacs, because there is an insulation layer of air between the inside of the barrel and the sac wall. This means that the heat from your hand will not heat up the air inside the sac and cause it to "burp" and deposit a blob of ink on your paper.

 

Richard can speak for himself, and I don't know who provided the information at fountainpensacs, but I don't presume to speak for them either. What I have said is my opinion. As a pen restorer, I tend to agree more with Richard, although I find his sizing to be a bit on the small side. Basically, I keep even sizes in only straight sacs, and I have never had a problem making them work.

Edited September 11, 2014 by Procyon

[LargeSofa]

thank you... I pretty much get it now... sac size need not be precise... I ordered a few based on Binder's size chart, will see how I feel about and if it feels too small or not... my guess is it will be fine.

[Procyon]

thank you... I pretty much get it now... sac size need not be precise... I ordered a few based on Binder's size chart, will see how I feel about and if it feels too small or not... my guess is it will be fine.

 

Yep, I suspect you will be fine with those sacs. Good Luck!

[Doug1426]

Thanks folks for a very informative thread.

[sulman2000]

I don't often chime in but I must say I agree Procyon. To state it simply - a correct sac is best on the smallish side - inserted without interference or friction. The sac chart we have on fountainpensacs.com is used by permission from Peter Amis of the Pen Sac Company. One of the reasons we carry such a large inventory of sacs is for the "purist". We have many many customers who simply will not restore a pen other than with the sac that was originally in the pen. Believe me I have tried to dissuade people from using a necked sac in favor of a straight sac but for the most part - except for necked sacs like the #15 X 2 1/8 which are no longer manufactured - they insist on putting a necked sac into the pen if that was the original sac that came with the pen. For some it's not just about getting the pen to work again but restoring to the original state. So for that reason we are happy to carry one of the largest inventories of sacs on the internet as a convenience to those restorers.

 

Getting back to the charts themselves - many new restorers do expect charts to be their savior. We receive emails daily about what size sac do I put into this pen or that pen. I always stress that charts are just a starting point and are often very inaccurate due to variables like pen shrinkage over the 70 or 80 years of their existence, or perhaps a pressure bar or j-bar hanging down a bit causing interference. Of course many newbie repairers want it right the first time - especially if they have only one or two pens to restore - and I don't blame them in the least. Suggesting an assortment of sacs to try get the best fitting sac is often not a viable solution for these individuals - after all why buy a bunch of sacs when you only have one pen to repair. In this case, I will suggest that they use a set a drill bits and insert them into the barrel of the pen - simulating sac insertion (blank side of course ) until one fits comfortably without friction or contact. They can then convert the drill size to 64th's of an inch and passed their measurement on to me. Even with this type of measurement I always recommend they buy one size down from their measurement. We always try to accommodate our customers often going back and forth with them for 7 or 8 emails before they make their purchase.

 

So I believe charts have their place -- one just has to remember that it's just a starting point.

 

Good luck to all on their pen repairs and restorations.

 

Sulman2000 --- Larry (owner)

 

http://fountainpensacs.com

Edited September 20, 2014 by sulman2000