Make Your Own Bullet Pencil Erasers

A Simple Way To Make Erasers For Your Vintage Bullet Pencils:

Bullet pencils are one of the best ways to carry a writing utensil out there: compact, pocket friendly and easy to adapt to your favorite wood case pencil. Therefore they will easily become an essential everyday carry tool.
With use comes the need for a bit of maintenance and fortunately this is VERY easy to do.
In this particular post I am just going to describe one possible way to replace the eraser. I have used this technique for years because it is reliable and fast.
Before I start though, I would like to say that bullet pencils are designed to make notes on the spot and are not the best design for prolonged writing sessions. If one keeps to the "quick and dirty" writing style that a bullet pencil was made for, it is understandable that I rarely use the eraser. For "quick" note taking I usually just cross out the mistake and keep going
but
every now and then the eraser is needed and in no time at all will need to be replaced.
In summary, I use a simple extrusion method that involves a brass tube and an eraser block of your choosing.

1.  The brass tube can be purchased at any hardware store for just a few dollars (these are the same small diameter tubes that can be found for modelers). To taper the edge one just needs to hand file a single bevel taper on one end. I personally use my 36" bench sander to make quick work of this. This will create a sharp plug cutter. The longer the bevel, the smoother the cut. You will be surprised just how easy it is to cut these plugs.
2. One really doesn't need a practiced hand to cut the eraser plug. Just keep the brass straight and push through the eraser block. 

Making a bullet pencil eraser: using the extrusion method

Making a bullet pencil eraser: using the extrusion method

3. When the eraser plug is extruded, it will come out in a slight hourglass shape. This shape will need to be controlled before inserting into the bullet pencils ferrule. First, I cut a little bit off the end to decrease the severity of the hourglass shape, then use a rubbery or tacky tape to compress the end. Electricians tape or a strong double sided tape is great for this purpose. A rubbery tape is nice because it can be pulled very tightly around the eraser plug and a double-sided tape is nice because it has a bit of tack to keep the eraser in place.
4.  Now that the eraser plug is compressed you will want to verify that it's outer diameter is just a bit wider than the inner diameter of the bullet pencil's ferrule. If the eraser goes in too easily it will be safe to assume that it will come out that easily. The tape will not only help control the optimal diameter, but it will also give benefit in two other ways: first, the tape will add a bit of strength to the eraser's overall length when cramming it into the bullet pencil's ferrele (greatly reduce breakage) and second will add strength if one decides to use a short pin through the ferrule or flair out a bit of the brass into the eraser (two techniques for further keeping the eraser firmly in place). I have found, though, that in general the pin technique isn't necessary when the eraser plug is measured correctly.

Making a bullet pencil eraser: controlling the hourglass shape of the extruded eraser

Making a bullet pencil eraser: controlling the hourglass shape of the extruded eraser

Eraser talk:
My 3 preferred erasers for bullet pencils are the Black Factis, the hi-polymer Pentels, and the Pink Pearl. I will say though that the Black Factis is my favorite. The black color doesn't look so dingy after being used and fits better aesthetically to a bullet pencil, darker colors complimenting dirty jobs.

Making a bullet pencil eraser: black factis is my favorite, but the hi-polymer and pink pearls are excellent options too.

Making a bullet pencil eraser: black factis is my favorite, but the hi-polymer and pink pearls are excellent options too.

5. The final step in the eraser making process is to slightly taper in the eraser into a truncated cone. In my opinion this shape holds up better to erasing and also goes in and out of the pocket easier. 

Making a bullet pencil: a quick sanding so the eraser tapers into a truncated cone.

Making a bullet pencil: a quick sanding so the eraser tapers into a truncated cone.

While ignoring everything I have just said about integrated eraser making,
I do have a couple bullet pencils that do require a more substantial pencil end erasers. These mobile writers are more likely to be found around the shop or free ranging in the truck. I use these fellows when mark making at a worksite or benchtop project. Erasing on wood or metal can be a bit more demanding than on paper. Pencil end erasers are a perfect fit in these cases.
Pencil end erasers come in a few options, the two I have here are the easiest to get. The one on the left is the small variety that can be found at any general store. These tend to do an ok job erasing (just ok), but they have to be held close to the tip when erasing. The one on the right can be purchased at an art store (we have a Dick Blick in town so that is where i got mine). These are the pink pearls of pencil end erasers. They do a superior job of erasing and have thick walls (heavy duty, takes a beating).

Making a bullet pencil eraser: using pencil end erasers.

Making a bullet pencil eraser: using pencil end erasers.

Making the post for this only takes a few minutes and last near forever. Below is a well beat up post that i made some years ago. The part of the post that fits into the ferrule is almost always wider that the i.d. of the pencil end eraser so this will be a two part process.  First, start with a scrap of hardwood dowel and sand down until it very tightly fits the i.d. of the bullet pencil's ferrule. When this fit is nice and tight no pins or epoxies will be needed. I recommend a twisting motion when inserting the post into the ferrule.
Then, with the wood post in the bullet pencil, cut the dowel to hold the pencil end eraser and sand down until the eraser can hold the eraser firmly.  The post cannot be too thick here because it will stretch out the eraser and it will break more easily when being used.

Making a bullet pencil eraser: showing off the wood plug that will accommodate the pencil end eraser.

Making a bullet pencil eraser: showing off the wood plug that will accommodate the pencil end eraser.

I am sure that there are many good ways to make a bullet pencil eraser, but these two ways work VERY WELL for me.