Navigation Menu
Site logo
Site logo
Site logo
Navigation Light bar
Buy Richard’s BooksBooks
Richard’s CollectionRichard's Pen Collection
Richard’s Pen BlogRichard's Blog
Reference PagesReference Info
Extra Fine PointsExtra Fine Points
The WritingsWritings
Pen  LinksOther Pen Sites
More Search Options

How to Replace the Sac in a Camel Fountain Pen

(This page published July 1, 2022)

Reference Info Index | Glossopedia  ]

Fountain pen
Fountain pen

The Camel Fountain Pen was an attempt during the 1930s to produce a pen that would make its own ink when filled with water. It wasn’t just a repackaging of the old World War I-style trench pen, however; it was a re-engineered design fitted with a supply of compressed dried ink that would last through many fillings, partially dissolving each time the pen was refilled. The Camel, like its several competitors, wasn’t really successful, and it didn’t last out the decade. But that doesn’t mean it was a bad pen. On the contrary, it is a very good button-filling pen, and it’s wortt repairing. But, as Hamlet said, “Ay, there’s the rub.” Replacing the sac in a Camel isn’t straightforward, and in some cases it can be quite a challenge. This article shows you how to do it, whether it’s an easy job or not.

Tools Required

Parts Required

Supplies Required

As you follow the instructions in this page, refer to this diagram to identify the various parts. The front and rear bands secure the ends of the pressure bar spring in place. Note that these bands are both complete circles; the rear band is cut away here to show how the pressure bar spring fits into the notch and groove on the thimble. The back end of the section is a mirror image of the thimble.

Fountain pen
The ferrule, which provides the threads at the back of the barrel for the blind cap, is not present in earlier Camel models. In pens without the ferrule, the blind cap is externally threaded and screws directly into the barrel so that the user could unscrew and replace the button, which was hollow and contained the necessary supply of compressed powdered ink. It appears that when Camel discovered that its ink-making system did not work as well as anticipated, the company added the ferrule to prevent removal of the button; Camel pens made after that time functioned as ordinary button-fillers.


Remove the blind cap. If it is externally threaded, and if things are really rotten inside, you might be able to pull the guts out the back by grasping the button. Stop if there is any meaningful resistance; the pressure-bar spring and rear band are prone to corrosion if the sac has died and leaked ink into the interior of the pen. Either or both could be ink-locked to the inside of the barrel, and you could break something. (It’s possible to make a new spring, and you might have to do that, but it’s better to save the original if it is still usable. Making a new band is also possible but more difficult.)

Using section pliers and a rubber gripper square, unscrew the section from the barrel. If it resists, apply a little gentle heat to the area of the barrel threads and try again. I have never encountered a Camel with the section joint secured by adhesive, but there are many Camels I’ve never handled so be sparing with the heat.

If you are lucky, you will now be able to pull the section assembly, with the guts attached, out of the barrel. As before, if there is meaningful resistance, stop. The sac might have leaked ink into the barrel, and if this has happened, the guts can be ink locked in place. In this case, I have found that th best option is to run the barrel assembly through an ultrasonic cleaner with Rapido-Eze; but if you do not have an ultrasonic cleaner, you can just soak the barrel assembly. Soaking alone might take a couple of days if the ink leakage was severe. A very, very long soak can deposit a milky film on the barrel, but you will be able to polish this film away.

With the guts out of the barrel, you can assess the damage, if any. The sac might be ossified and broken. The pressure-bar spring and one or both of the bands might be corroded. The first order of business is to clean off whatever deposits of ink or corrosion that you can get off easily. Next, carefully use the X-acto knife or sac removal tools, or both, to slide the bands off their perches toward the middle of the sac, exposing the T-shaped ends of the pressure bar spring. If there is serious corrosion, the pressure bar spring might look more like the one shown here, which came from the black pen illustrated at the top of this article.

Dead pressure bar

With the pressure bar spring exposed at both ends, the pressure bar should fall off. (It might be stuck by dried ink, so you might need to lever it away from the sac or the section or thimble.) If the sac is still in one piece, cut or break it in the middle to separate the two end assemblies. Using the sac removal tools, remove the remains of the sac and clean the section nipple and the matching end of the thimble. Be sure to clean off any corrosion from the grooves and notches where the ends of the pressure bar spring fit. Do not dispose of the pressure bar if its spring is not usable!

Use the X-acto knife and sandpaper to remove as much corrosion as possible from the bands, pressure bar, and pressure bar spring. If you are lucky, these parts will all be in usable condition. This iamge shows a pressure bar and spring in like-new condition.

Pressure bar and spring

Sometimes one of the bands, usually the rear band, will have split due to the tensile stress exerted by corrosion on its inside. If you have a split band, you can use sandpaper to clean the broken end surfaces and the outside surface adjacent to the split and then solder the band back together, being careful to see that the split ends line up perfectly. Use the X-acto knife and sandpaper to remove excess solder from both the inside and the outside of the band.

If there is ink around the nib and feed, now is a good time to soak the section assembly in pen flush until it’s clean. Flush thoroughly with clear water, blow through the section to drive out most of the moisture, and then dry the assembly. Clean the inside of the barrel and cap at the same time, and use a twizzle to dry their interiors.

Measure X, the distance between the notches forming the T-shaped ends of the original pressure bar spring. Write it down; you will need this information later:

Measuring pressure bar length

This is the length to which you should cut the sac, removing and discarding the closed end. You need a tube open at both ends.

Making a New Pressure Bar Spring

If the pressure bar spring is in usable condition, with little or no corrosion damage and with both T-shaped ends intact as shown earlier, you can skip this section. If that’s not the case, read on.

Loosen the original pressure bar’s hold on its spring by inserting the blade of your X-acto knife between the pressure bar’s tabs and the spring, one at a time, and wiggling to loosen the joints. Now clamp one end of the pressure bar spring tightly in the vise, with the assembly sticking out horizontally as in the photo below. With the chain-nose pliers, grasp the outer end of the pressure bar itself, and pull the pressure bar off the spring.

Pulling a pressure bar apart

Repeat with the modern replacement pressure bar assembly. Retain the spring. Discard the pressure bar; you will not need it.

The drawing below shows the shape and dimensions for the ends of the new spring:

Drawing of pressure bar spring end

If needed, use the jeweler’s hammer to flatten the ends of the replacement spring. Then clamp one end of the spring in the vise, leaving approximately 1/3 of the bar visible, as shown below. Then file a notch near the clamped end, using the dimensions given in the drawing above. This is much less difficult to do if you have a jeweler’s visor as described in the Tools Required list above.


Repeat on the other side of the spring. The dimensions of your two slots do not need to be precise; check from time to time to see that the spring fits into the notch and groove on the thimble. When it fits, deburr it so that it won’t damage the thimble in use.

Thimble notch

Measure the sac-length distance (X) along from the notches to find the location for the notches at the other end of the pressure bar. File the second set of notches, and then cut off the bar to yield a final length so that the second end also fits into the notch and groove on the thimble. Deburr the second end.

Slide the original pressure bar onto the new spring, and center it optically. Squeeze the tabs in the vise or with pliers so that they grab the spring.


The photo below shows the parts of the Camel. Compare with the cross-sectional drawing shown earlier.

Parts of a Camel pen

If you had to repair a band, you need to reduce the diameter of the thimble where the band fits over it in order to prevent the thimble from splitting the repaired band. Use a file, a knife, or sandpaper, working all the way around, removing a tiny amount of material and checking frequently until the band just fits around the thimble without being forced.

Measure distance X from the open end of the new sac. Cut the sac at that point, and discard the closed end. You need a tube with both ends open.

Cement one end of the sac to the thimble’s nipple, and let it dry. Slip one band over the sac. Making sure that the pressure bar faces the sac, slip the pressure bar assembly under the band and line up the T-shaped end of the spring with the slot and groove in the thimble.

Assembling the back end

Slide the band up over the end of the sac, pressing the end of the spring if necessary, until the band fits snughly against the step in the thimble that prevents it from going farther.

The back end, assembled

Slip the other band over the sac and the pressure bar spring.

Installing the second band

Cement the other end of the sac to the section’s nipple, aligning the groove in the section with the pressure bar spring, and let it dry. Slide the band up over the end of the sac, pressing the end of the spring if necessary, until the band fits snughly against the step in the section that prevents it from going farther.

Let the complete assembly dry!

Installing the second band

If you have not already removed the button from the thimble, do so now. Shellac it securely back into place and let it dry thoroughly. Replacement buttons with new ink in them are no longer available, and they didn’t work very well anyway, so the idea is to prevent any leaks from the button/thimble joint — permanently — so that you can use the pen as an ordinary button-filler.

Assemble the section, with the complete guts assembly, into the barrel. Install the blind cap, and you are done!

Fountain pen

  1. Although not listed in my Essential Tools and Supplies for Pen Repair page, a magnifying visor is one of the first nonessential tools you should consider adding to your armamentarium. I have used a Donegan OptiVISOR for a quarter of a century, and I can recommend it for quality and durability. There are other brands that look the same but cost less; in my experience, even if the lenses are acceptable, these visors are otherwise cheaply made and will not serve as well or as long as the OptiVISOR.  Return

The information in this article is as accurate as possible, but you should not take it as absolutely authoritative or complete. If you have additions or corrections to this page, please consider sharing them with us to improve the accuracy of our information.

© 2022 Contact Us | About Us | Privacy Policy
Richard Binder - Fountain Pens Like RichardsPens on Facebook