A Challenge Posed: Making a Seal on Ball-Tip Ink Cartridges for Longer Term Storage

Protect that ballpoint, rollerball or gel ink cartridge in-between rotations:

There are big differences between the properties of these inks, however they are all commonly deployed by a ball-tip ink cartridge. 

Today's ink formulations and self contained ink cartridge units have greatly increased the length of time a pen may be successfully stored. If an ink cartridge does fail to write after a prolonged period of time, it seems that the greatest culprits are when:
 1-the ink is exposed to air at the ball-tip, then dries at the ball.
2-the suspended particles flocculate creating a dam in the ink flow.
 3-an air pocket has formed between the ball and the reserve of ink.

Now, if there is a pen that will need to sit out of rotation for a lengthier period of time and you want to take some precautions to increase the chances of a successful storage, then tackling the top 3 problem areas is a good start. This post is specifically about two techniques to help prevent the ink from being exposed to air at the balled-tip of the cartridge. 

Protecting the ink flow by creating a seal around the cartridge's ball mechanism:  

 The size of the ball is the main difference between the types of cartridges. The truth is that each style of pen uses a range of sizes but the most common sizes can be generalized as:
Ballpoints commonly range between .7mm to 1.omm (most common)  
Rollerballs commonly range between .5mm and .7mm
Gel pens commonly range between .3mm and 1.0mm
Despite all of these sizes, the actual ball mechanism is still relatively very small. This is good because that means the seal needed to wrap the tip will also be very small.  

Two techniques to help prevent the ink from being exposed to air:

I am sure there are many possible sealants out there, but these two I have found interesting because they are: made from easy to source materials, they are conveniently already in my home, fast to apply, fast to remove and the both create a reliable seal.

Technique #1: Creating a seal using Plumber's tape. Also known as Teflon tape, PTFE tape or Polytetrafluoroethylene film. This is the faster of the two to apply and easier to remove. A few other perks from using Plumber's tape is that it comes in these small rolls that are inexpensive, easy to store and create no mess.
Technique #2: Creating a seal using an air drying rubber coating called Plasti Dip. This material has a much greater adhesion and an even tighter fitting profile than the Plumbers tape. The down side, is that it takes 10 minutes to dry and 30 minutes to fully cure.

Making a seal with Plumber's tape:

In the following image gallery I have 3 different ballpoint pens that I use as examples:
1- A nock pen with good clearance between the cartridge and the barrel= Parker Jotter
2- A capped pen = Fisher Space Pen
3- A nock pen with little clearance between the cartridge and the barrel = Lamy Noto

Application is actually EXTREMELY easy and is best shown in a short video.

Removal is even simpler yet.

Below is a recipe card for making a seal with Plumber's tape. Please feel free to save these images for your own use. 

Making a seal with Plasti Dip:

Below is another recipe card that I invite you to use. Here you will find the 4 ballpoint pens from from the Plumber's tape card plus an image of a Pilot G2 (on the second page's bottom left pane). Air drying rubber coatings come in both aerosol spray or in a liquid paint can. Either can be used with relative ease. 

In conclusion, I find that both techniques are viable seals. The Plasti Dip will create the more durable and air tight seal but the prep time and mess factor greatly detract from its attractiveness.

Disclaimer: I am very comfortable trying these on my own writers however,  I do not take any responsibility for anyone else trying these techniques on their own equipment.
It is really a shame that I have to make a disclaimer, but "needs must when the devil drives". (There is always someone who is surprised by how hot the coffee is.)