A Word About (supposedly) Silicone Pen Sacs

Word in the fountain pen community says the silicone sacs we have been purchasing for years really are not pure silicone, they contain.... vinyl!  What's wrong with vinyl you might ask?  Much is wrong with is, not only is soft vinyl somewhat toxic (plasticizer leech, phthalates anyone?) it has the ability to melt and destroy other types of plastic, celluloid and polystyrene are amongst these and most pens are made of those.  You might remember this having happened with some your toys when you were a child, you haphazardly toss your toys in the toy box and a soft vinyl toy happens to come to rest on top of one made of a hard plastic.  You go on vacation for a week and come back to find that the vinyl toy has melted the hard plastic toy where they touched.  Or maybe as you grew up you stored some of your childhood toys together, hoping that someday you would be able to pass them along to another child?  Maybe you take that box down when you find out someone in the family has a kid who might enjoy those toys, only to find some of them have melt marks and gummy plastic, maybe a toy containing both vinyl and hard plastic parts is in the process of self-destruction (dolls and action figures with vinyl heads and limbs and hard plastic bodies).  It's not always a process that will take place over night or even over a few years time.  This is what can happen to your pens if you leave the vinyl containing sac inside, so it's best to remove them while there is still time.

Today I removed all the vinyl sacs from my pens and I didn't find any damage, which is good considering some of these sacs have been in a pen for about six years.

Right now the only place to buy pure silicone sacs is:

http://www.vintagepens.com/catill_nibs_parts.shtml   (no affiliation)

They are only available in limited sizes right now, but the proprietor is working on making other sizes available.

You might also want to watch this:

Suspect Silicone Sacs: removed from my pens, the one on the right looks suspect to vinyl deterioration

All of this makes me wonder if pen sacs could also be made from TPE.  It's a plastic that is used in medical devices and implants and looks and feels much like silicone.

Exploded View of Parker Duofold

A look at a very popular, well designed and engineered fountain pen.

Parker Duofold Jr

Part of the beauty of the Duofold's design is that it is easily broken down into it's most basic components.  There is no need for any special tools (like an inner cap puller) to take this pen apart, this allows for damaged parts to be replaced easily.  The Duofold is also one of the simplest pens to repair, first you remove the blind cap at the end of the barrel and pull the button straight up and out without rocking it side to side (that could crack the blind cap nipple).  Next the pressure bar is eased out, they are designed to fit through the hole that the button is placed in.  After that you can open the pen, the threaded section makes it very easy to do.  Although it should be noted that 'streamlined' Duofolds have a friction fit section.

Streamlined Duofold Jr: the only difference is the friction fit section and the slightly tapered,  rounded off ends.  This pen also still has its original factory three-part pressure bar.

Duofolds were streamlined sometime around 1929 in an attempt to keep up appearances, competing pen makers had come out with radically streamlined pens and Parker wanted in on the action while retaining the Duofold's classic shape.  This pen model introduced sometime in 1921, although there was a similar model pen, the Parker Jack-Knife Safety that debuted in the late teens, utilizing the same basic shape and filling system.  The first Duofolds were made of hard rubber in either Chinese Lacquer Red (more burnt orange than anything, earned the pen the name Big Red), and plain black.  Celluloid or Permanite pens as Parker called it came out around 1925.  The Duofold was released in several sizes throughout the time it was on the market, oversize, junior (standard), a ladies ring top pen and a mens vest pocket ring top, there were also several variations on cap bands, the double band seen on the pens above being the most common.  Being a popular model the Duofold was on the market as a button filler until 1940, when is was drastically redesigned and released as a Vacumatic filler (more on Parker Vacumatics in a future post).

Left: Streamlined Duofold friction fit section.  Right: Original (flat-top) threaded section.

How Does it Work?

When the button is pressed, the pressure bar is forced down and bows outward, depressing the sac.  It's a very fool proof and failure proof filling system as there is little in the way of moving parts that can break.  When the button is released the bar goes straight allowing the sac to take in ink.  The original factory pressure bars have a lip that rests on the blind cap nipple, which holds the bar in place.  The new replacement are longer and rest against the section of the pen.

New Two Part Replacement Duofold Pressure Bar: When the button is pressed, the bar bows out depressing the sac.

Duofold Jr. seen above back together

Several Different Models- L to R: Flat-top 'True Blue' long, jade green Jr. streamlined, red flat-top Jr., chased hard rubber Deluxe Lady Duofold

Fountain Pens- Replacing a Sac

Disclaimer: Proceed at your own risk, I will not be held responsible to any damage you do to your pens.  The directions I present here are standard procedure for replacing sacs in lever filling pens.  Use common sense, if you don't feel competent enough to do these repairs don't do them.  Please send your pen off to a repair person.  Please keep in mind that sixty year old materials may be brittle due to age and sometimes a pen will just break even if you follow all the directions carefully.  Everyone who has repaired many of pens can vouch for me.

More often than not when you come across an old pen the sac will be bad- the rubber thing on the inside that holds the ink.  Pen sacs were and still are made from natural latex, which as it ages loses its elasticity and becomes hard and brittle, just like tires on a car or bike or other items made from natural rubber.  Other times one is lucky enough to come across a pen that still has a good sac, usually newer pens dating from the late 1940s to early 1960s when cartridges and ball points became popular.

Todays patient: Waterman's 452 1/2 V, sterling silver filigree over hard rubber

So, how do you know if a pen has a bad sac?  It's usually really easy to tell, first try lifting the lever if it's a lever filling pen like the one pictured above.  If the lever doesn't lift chances are the sac is hard and unyielding, if this is the case don't force it, you could end up breaking the the pin or c-ring that holds the lever in place.  If the lever does move but you still suspect the sac might be bad, give the pen a shake.  Sometimes a sac will crumble and the loose pieces will be rattling around inside the pen, no rattling means your sac should still be good and you probably don't need to do anything to the pen other than give it a basic cleaning.  If that is the case, to be sure the sac is good and has no leaks simply fill the pen with water and let it sit over night, in the morning check around the lever, or button in the case of button filling pens for dampness.  Any dampness means you have a leak and the sac will still need to be replaced.

Where to Begin

Replacing your first sac can be somewhat daunting, it was for me the first time I did it six years ago.  There are parts you need to purchase, unexpected surprises, precautions that need to be followed and the chance something may go wrong.  Plastics that are fifty plus years old can be fussy, they may have shrunk over the years, become brittle or can be undergoing degradation depending on how they were stored and treated.   For example celluloid can be destroyed by storage in damp places or by UV light or being kept in sealed containers as it needs to breath.  Hard rubber is sensitive to UV light and dampness can badly discolor and degrade it.  Polystyrene plastics, which became popular during and following WWII are notorious for shrinking and becoming brittle.  At the time they were a new and untested technology, not to mention the best materials were going to the government for the war effort.  It's very common to find Eversharp Skyline pens with cracked and distorted barrels and caps because of this.

Some items you will need: Amber or orange shellac, a small flashlight, eyedropper (syringes work well too) small brushes, pocket knife (file and scissors very useful), rubber kitchen grip, sometime to scrape away old sac remnants (hair pins work great for this, some people like dental tools).  And sacs! (not pictured)

First start by getting together all of the items you will need, many of them can be found around the house or purchased inexpensively at your local hardware or drug store.  Brushes can be found at pet or aquarium stores near the fish tank filters and pumps, but cotton swabs work too. You will need a heat source to warm the section and make it easier to open.  Sacs and other pen parts must be purchased from a specialty supplier, links provided at the bottom of the page.  After getting most of these things together you're ready to open the pen.

Pen is opened: old sac remnants pour out

I use a hair drier to heat my pens to get them open, I know there are people out there who use heat guns but after I had a bad experience with one I haven't used it again. (melted pen anyone?)  I should note I have also heard others mentioning melting pens with hair driers, so if yours gets really hot don't use the highest setting.  With the hair drier heat the pen evenly around the threads until they feel warm, then try twisting the section, to get a better grip use a rubber kitchen grip.  If the section doesn't want to turn don't force it too hardly, let the pen cool and heat it longer and try the section again.  Keep doing this until it comes loose, be patient, in many cases the pen hasn't been opened since it left the factory.  Also, there could be a load of old ink cementing the section into the barrel, a plastic or celluloid pen can be soaked for about an hour in cool water up to the barrel threads.  Hard rubber pens should never be soaked like this because water can discolor them.  Neither should pens made from a material called casein, it is made from milk protein and will melt when exposed to water.  These pens are mostly European in origin and not common in the US.  Casein can be identified with its sour or burnt milk smell when rubber between your fingers.

When you get your pen open the old sac needs to be removed.  Sometimes it will fall out in one piece, or only pieces will fall out like in the above photo.  If there are bits still stuck inside this is when you use your hair pin, dental scaler, small paint brush handle, ect to break them up.  Using a small flashlight you can look inside and see if there are any stubborn pieces stuck inside.  Once you have all of the old sac out you can clean the pen.  A soak in cool water will usually clean a nib, plastic and celluloid pens can be rinsed with cool water to remove any old ink inside and out.  Eyedroppers or syringes work well for this.  When you are finished dry everything well inside and out, paper napkins and towel work great for this.  Stubborn ink clogs in nibs and feeds can be tackled with diluted ammonia in water or dish soap.

Placing the bulb of an eyedropper on the section nipple is a good way to flush a nib and feed.  Flush until the water runs clear.

Once you have your pen clean you can find out what sac you need.  Pen sacs are available in different sizes and styles to fit different pens.  Suppliers provide lists of sizes for popular pen models and directions for finding what size you need if your pen is not listed.  Since I do many repairs I buy bulk packages with an assorted sizes so I almost always have something on hand that will work.  There are also silicone sacs, which are great for celluloid pens that are prone to discoloration due to a chemical reaction between the colorant in the plastic and a gas degrading latex produces.

Trying on sacs for size: Although some will disagree with me I try sac until I find the one that fits best

Installing Your Sac

Pen sacs come in one length so you must find out how much you need to cut off in order to get it the right length.  It is done by inserting the sac into the barrel until it is all the way to the end and then pinching it with your fingers at the bottom.  Pull the sac out of the pen and trim it off right above your fingers.

Just like this

If you haven't already noticed the sac is still not short enough, one has to account for the section.  To determine how much more you have to trim, lay the sac next to the barrel and the section and pinch it where you need to cut it.  If you haven't already done this, clean the section nipple where the sac attaches.  Finger nails or a file will help you with this.

Like this...

... And this

Now I bet you are wondering what the shellac is for and now is when you need it.  Shellac has been the way sacs have been glued to the section nipple for years.  There are some who use super glue, but don't do it, it will only cause problems for future repairers or yourself if you have to do later work on your pen.  Spread the shellac evenly over the section nipple and slip the sac over it, let it dry for about thirty minutes before trying to put the pen back together.  Pat yourself on the back, if you've made it this far you're doing a great job!

Glued... err shellacked on pen sac

After thirty minutes are up (I say thirty minutes because you're less likely to have problems with the sac slipping off while putting the pen back together if the shellac has time to dry) ease the section back into the pen.  Coating the sac in talc will help it slide in easier and helps prevent latex rot, please note you have to use 100% pure talc, not baby powder or body powder, these contain oils that will rot your sac.  A little heat will help if it's being stubborn.

The Last Steps

Congratulate yourself, you have fixed a pen that's been out of order for years...

... Ink...

... Write!

A Few More Things

After doing repairs for so many years you start to forget how overwhelming and intimidating doing your first can be.  You begin to take for granted what now seems to you to be common sense.  Here I have listed a few more things that one should consider.

- Never use acetone or isopropyl alcohol (rubbing alcohol) to clean a pen unless you want to destroy it.  Both of these eat celluloid and will damage other plastics.

-Never use hot water on celluloid it will make it irreversibly cloudy.  Stick with cool or room temperature water.

- Never use metal polishes (Brasso, ect) on pen furniture (trim).  It can ruin the plating and plastic.  If you are seeing what looks to be tarnishing it's because the plating is worn away and the base metal is exposed.

- A sac that is a little too small is better than one that is too large and is crammed inside the pen.

- Some pens have threaded instead of friction fit sections, unless you are absolutely sure the pen is friction fit treat it like it is threaded.  This will prevent stripped threads, cracked barrels and sections.

- Always assume the pen you are working on is made of brittle material.

- Never force any stuck parts.  Gentle heat and soaking (depending on pen material) can usually loosen them.

- Keep celluloid away from open flame and extreme heat.  It is extremely flammable!

- Do no harm.  That is if nothing is wrong don't fix it.

Pen parts links*:

http://www.pensacs.com/

http://www.woodbin.ca/

http://www.pendemonium.com/penrepair.htm

In the UK

http://www.penmuseum.co.uk/spares.htm

Please feel free to ask questions.  I might have the answer or can point you in the direction of someone who does.

* Not in anyway affiliated, just a happy customer or have heard positive reviews

Fountain Pens 101

When I started this blog I promised I was going to make some posts regarding fountain pen repair.   Since my last posting I began considering where I wanted to begin.  First I though I would start with my most recent repair, yet knowing there are a few people out there wouldn't have a clue of what I was writing about I though I'd begin with something a bit more basic.  Jumping straight into a topic that is considered esoteric to most is a great way to bring about confusion.  My focus in pens is mostly pre-1960s so this post is going to be looking at fountain pens in their most essential form dating from that time period and earlier.

Basic Anatomy

Below is a diagram displaying the form of fountain pen one is most likely to encounter if they pick up any pre-1960s pen.  This configuration was most commonly produced by pen manufacturers from the early 1920s to the late 1950s when cartridges became the preferred method of refilling a pen and before ball points took the public by storm.

Fig. 1  Esterbrook SJ: fountain pen in most basic form

Its most basic parts consist of the barrel or body of the pen and the cap to protect the nib or tip.  Other features should be common to anyone who has ever used a pen, such as the clip and cap band.  Although at first glance the cap band may appear to be merely decoration it is functional for it strengthens the lip of the cap and protects it somewhat from the stresses of use and posting (placing the cap on the rear of the pen while writing).  Some of the other features may leave a few scratching their heads, wondering why someone ever thought to put such things on a pen.  Why a lever?  Or what purpose does that little hole in the cap serve?  Well, no lever would mean no ink to write with- it is the means of filling the pen.  Lifting the lever depresses a thin bar of spring steel on the inside of the pen, which in turn flattens and forces the air from a rubber sac or bladder.  Allowing the lever to spring back into place while the nib is submerged in ink fills the pen, with the ink taking the place of the displaced air- kind of like an eyedropper.  Below shows what an ink sac looks like outside of a pen.

Fig. 2  Ink sac attached to pen section

So what about the little hole?  It's there for a good reason.  When the cap is removed from a pen a small amount of suction is created, which great enough can draw ink from inside the pen thus creating an ink blot.  Breather holes reduce this suction and make sure the ink stays inside where you want it until you are ready to write.

Under The Cap

Before one looks under the cap one must realize that most pens from this time period have threaded (screw on) caps.  Again there is a good reason this came to be, which will be touched on farther down. Attempting to pull off a threaded cap can strip the threads or crack the cap itself. 

Fig. 3 Nib and section

Other than the nib, the section is part of what makes the fountain pen functional, it holds the nib and gives the user a place to rest their fingers and also creates a seal against the inner cap- a sleeve fitted inside the pen cap.  Looking closely at the bottom of the section closest to the nib one can see that it is slightly flared and creates a flange.  When the cap is screwed firmly on the pen the section and inner cap meet, keeping air from getting in and drying the nib and ink from getting out and going all over one's pocket.  The section is where the pen comes apart when it needs to be opened for servicing (please do not attempt to do this unless you know what you are doing, it can be dangerous* for you and the pen if you follow the wrong directions.  Another post will touch on this soon, I promise).  Of course the nib is what does the writing and come in a wide variety in vintage pens.  There are extra fine, fine, medium and bold nibs.  Stiff nibs and flexible nibs and nibs made of steel like the one shown above, or 14k gold and 18k gold.  What is best all comes down to personal preference as there are simple steel nibs that perform better than some of the more expensive gold nibs.  The majority of quality vintage pens were fitted with 14k gold nibs.

Fig. 4  Underside of nib

Beneath the nib is the feed and as its name implies its function is to feed ink to the nib and air back into the pen.  Feeds in their most basic composition have channels carved in the top by which the ink travels, fins like in the photo above were a later innovation added to collect excess ink and prevent blotting (blotting usually isn't that bad of a problem no matter the feed in a clean and properly maintained pen yet it does happen).  They were machined from hydrophilic material like ebonite (hard rubber) and nowadays in most modern fountain pens injected molded from plastic and sometimes treated with a hydrophilic compound to make them channel the ink better (cost savings, not an innovation).

Nib tipping is added to the ends of the nib tines to make them more wear resistant, paper is abrasive and over time would wear away at the nib faster if it was not tipped, especially softer gold nibs.  Tipping is formed of very hard alloy called iridium and is welded to the nib separately during production.  Some steel nibs like the one shown do not have iridium tipping, instead the ends of the nib and rolled over and heated forming a smooth, durable surface.  Even though iridium tipping is tough it is not bullet proof, in other words it's possible to find vintage pens with their tipping worn away.  They will write scratchy but the tipping can be replaced by a restorer that specializes in nib repair, which in some cases is cheaper than trying to find a comparable replacement.

While this post only shows and speaks about the basics, I'd like to point out there are many other filling systems one can and will encounter once they start looking at fountain pens.  In the future I plan to make further posts highlighting some of these systems, which can seem overwhelming to someone who is just starting out.

Please feel free to ask any questions you might have.  I'll try to answer what I can or point you in the direction of someone who I know should have the answer.


*I say dangerous because there are some repair books and old out of date repair manuals circulating on the internet that advise the use of open flame or a heat gun to open pens.  The majority of pre-1950s fountain pens are made of celluloid which is highly flammable, so open flame and heat guns that can get hot enough to ignite celluloid are very dangerous.  Old materials can be fussy and if you don't know what you are doing you can cause irreversible or costly damage to them.  Then there are pens with threaded sections and friction fit sections.  Just do not do anything unless you are sure of what you are doing.