Tag: restoration

Talc and Asbestos

For over a century talc has been used as a standard dry lubricant for rubber fountain pen sacs. The slippery mineral dust helps to protect the sac from friction damage when it is depressed by a pressure bar. This lubrication is also essential for Parker Vacumatics and other pens where a sac is folded in on itself; rubber sticks to itself, and the mechanisms of these pens simply do not work without lubrication.

Talcum Powder

In recent years there has been a great deal of attention given to the possibility of asbestos content in talc products. Asbestos is often found in the same deposits as talc (http://dx.doi.org/10.18103/mra.v8i5.2097), and has been proven to be a carcinogen (cancer-causing). While there are cosmetic-grade talcs, it is recommended that any talc without reputable certification as asbestos-free be assumed hazardous (Asbestos in Talc Powders and Soapstone – the Present State [2007]).

I like my lungs. And suddenly the little puff of white coming out of a lever slit after you have replaced a sac feels ominous, instead of satisfying. None of the talc suppliers I have contacted seem able to provide information about sources, or safety. So, following the excellent advice of the German government (see link above), Restorers Art is immediately discontinuing the use of talc as a sac lubricant.

An Excellent Alternative

All this being said, there is good news! There is an excellent alternative dry sac lubricant.

The Ka’bah-e Zardusht, a lifetime supply of chalk–if demolished.

The personal care industry turned to the use of vegetable starches, like corn starch, as an alternative to talc. We investigated that as an option. We found the particle size too large, and starches turn gummy if wet, which is a terrible quality for our application (think pen leak here: eeeew!)

We have, however, found an excellent alternative: precipitated calcium carbonate (CaCO₃). This is a powdered chalk produced from limestone, and has been used for centuries in bookbinding and shoemaking. Particle size ranges from 0.2-30 μm (compared to talc at 0.2-100 μm). The “precipitated” description means that the chalk has been purified and contains nothing but CaCO₃.

We have done our own experimenting (the best kind!) and created a slurry of CaCO₃ in filtered water. We let the water evaporate, then tested the newly dried CaCO₃. The wetting-drying cycle did not seem to affect the lubricating quality of the lubricant in any way. Which for us is a big win! It does not dissolve in water, but rather forms a suspension.

This slurry has a pH of about 9.0, which is alkaline. This is actually good for us, because the interior of a pen is damaged far less by alkaline conditions than acidic. (As an example, steel pressure bars, buttons, springs, or nibs will rust very quickly in acid fumes, and even corrode right away when bathed in acid. Alkali won’t affect these materials this way.)

Another advantage is that CaCO₃ is inexpensive, and fairly easily available. And a 100 gram bag will be enough to last for years of new sacs.

While the chances of contracting cancer from a bit of talc in a fountain pen may be minimal, we like to play it safe. CaCO₃ is a cheap, effective, and available alternative. So why not choose safe? After all, with all the nasty chemicals out there, there is nothing wrong with making sure the pens we carry with us, and use every day, are the safest things around!

March 5, 2023
What’s Wrong With My Parker Pencil?

When it comes to congenital defects, time always tells. This past week we have had four Parker pencils on the bench, and each had the same problem. And that problem was the result of a design flaw that would only reveal itself over time.

The Design

From the time Sampson Mordan first patented the propelling pencil, in the early 1800s, most pencils used a helix-driven shuttle to propel, and eventually repel and expel, the lead. Parker used this design extensively until the 1940s, when they adopted the (far superior, in my opinion) German dual-clutch mechanism in the 51 aerometric pencils. Even then, they still used the helix-driven mechanism in some models. This system was used in, at least: Duofold, Challenger, 51, 21, 45, 61, 75, &c &c. Also, Sheaffer. Also, Waterman. You get the idea.

In this design, the shuttle holds the lead, and travels up and down a slotted inner shaft. Two small knobs of brass protrude at right angles from the shuttle, and are long enough to pass through the slot in the long shaft and act as keys. (Note: “key” is the proper mechanical term. It sounds so much better than “knob” that I’m going to use it for the rest of this article.) This entire assembly fits inside a helical sleeve. When the helical sleeve is rotated, the keys from the shuttle are guided by it up and down the keyway (See? So much better than “knobway”!) that runs the length of the shaft.

Here is a photo of all of the parts, which will hopefully help you to imagine it all together:

And here, at the prompting of Apprentice Em, is a video to clarify further. The two spots I point out are the drive keys for the shuttle, inside the tube:

The First Problem

There are a couple of problems with this design, one minor and one major. First, the minor.

Everything you see is made of brass. Brass is an excellent material generally, and has been used in small machines for centuries. However, brass tends to wear out when it is abraded. This is one reason, as an aside, that watches use jewels as pivot points: brass would wear too quickly.

Also, like metals have an affinity for each other; they tend to stick. So, in very good designs, two parts which bear on each other tend to be made of unlike metals, like a steel shaft in a brass bushing. There is less material loss because the parts don’t want to stick together, and friction (thus wear) is minimized.

So, in our pencil mechanism, you have a brass shuttle sliding along a brass track, with a brass helix driving it. Can you see where there might be an issue?

The Second Problem

This brings us to the second, far more substantial issue: the way the shuttle is made.

In these pencils, the propel-repel-expel action was accomplished by means of a two-part shuttle. The shuttle consisted of an outer sleeve, with an inner shaft. The lead fits in the outer sleeve, and when the shuttle reaches the end of the action (when the lead is spent), the inner shaft is engaged, pushes forward, and pushes the last little bit of lead free. When the shuttle is retracted, the inner shaft retracts, allowing you to seat a new piece of lead in the now-empty socket.

The inner shaft is simply a brass rod with the last few millimeters bent sideways, forming one of the keys that is engaged by the helix drive. This is not bad.

The outer sleeve part of the shuttle is a flat piece of brass, about 0.25 mm thick. It is formed into a cylinder, into which the brass shaft fits (can you see the seam in the photo? It is all just press-fit into shape.) And this is the biggest issue: the main drive key is made of two flaps of this very thin sheet, pushed together. Now, a one millimeter piece of brass rod will take awhile to wear. But two 0.25 mm flats will wear much more quickly. And this is exactly what happens.

The front key is the main drive point for the shuttle. Remember, the rear one only engages when the lead is spent and needs to be ejected. This means that the tiny part taking the brunt of the wear, and without which the lead cannot move in and out, is also the weakest part of the pencil.

Here is a photo of a reasonably sound shuttle drive key, with a worn one above it (click to embiggen).

What you can’t see is that, when you take apart most pencils of this design, both sides have worn away. Then they fold over, inside the slot in the inner shaft. Then the ejection shaft key is the only one engaged, and the next time you try to replace the lead, the ejection shaft won’t retract properly and you can’t ever fit a new piece of lead in place, ever!

Hard Conclusions

How many pencils are affected by this kind of debilitating wear? About 80% of what we have handled, several hundreds of pencils.

Is there a repair? Nope. You can replace the worn part, if you can find a sound one. The only repair solution we can see is to use a micro-welder to weld on a new key: a nice, solid one. Which also means taking an hour to strip it all down, clean it, and assemble it again. But considering that the effort and equipment that would take is about the same as re-tipping a nib, or repairing a Waterman lever box, it’s not likely to happen, except as a labour of love. (Hmmm…$20, or $150? $20 and lovely, or $150, and also lovely? Such choices…)

The sad truth is that many of the beautiful old pencils, matching beautiful old pens, are worn out. Because of a bad engineering choice, which maybe, just maybe, was part of planned obsolescence.

Yard-o-led used a similar design, but far more robust parts. And the Germans, of course, used a completely different design with only one moving part, and no wear points. So if you want a good, beautiful, useful, robust vintage pencil, buy a Pelikan. ; )

July 16, 2022
All About Nib Smoothing
A scratchy nib is one of the most common issues with a fountain pen. Probably 70% of our repairs include some kind of nib repair. As a result, the topic is one of the most enduring in the pen community, both in real life and online.

As with so many popular subjects, opinions abound, and thus questions. Having repaired thousands of pens over the last twelve years, I thought I would publish this list of nib smoothing “frequently asked questions”.

Why is my pen scratchy?

Don’t try this at home-or anywhere else!

The simple answer is: damage. The tines of a nib, and the tipping on the end, must remain carefully aligned. This allows for proper ink flow, and smooth writing. Nibs made of gold can be bent–some quite easily–out of alignment. Normal use shouldn’t be a problem, but there will be a problem if you: drop your pen; try to flex it too hard; insert anything foreign (like a thin knife, perhaps to clean it out).

One defect that causes scratchiness is when one of the tines is (even slightly) twisted in relation to the other. Unless the tines are properly parallel first, nothing else will make it a smooth writer. We have seen tipping material sanded away to nothing, because the person working on it didn’t realize the tines were misaligned. How can you tell if this is the problem? Unless you have a good source of magnification, you will have a difficult time knowing. A loupe or magnifier with a power of at least 15-20x is needed to tell for certain. And even then it takes a practiced eye.

Are some pens more prone to scratchiness than others?

The more history a pen has, the more likely it is to be damaged in this way; a vintage pen found in an antique shop will probably need some nib work! Also, any nib with gold content over 14k (58.5% gold content) will be more prone to damage.*

What is the best way to smooth my scratchy nib?

Honestly, take it to a professional. Nib smoothing is one of the most challenging aspects of pen repair. It is easy to make the problem worse. And, because there is a limited amount of tipping on each pen, you could actually destroy the nib.

But I really, really want to smooth my own nibs! Do you have any suggestions?

I do, but proceed at your own risk!
1. Start with pens you don’t care about. You will destroy the first few.
2. Richard Binder has kindly and generously provided the notes from his nib smoothing workshop. They are excellent, and include detailed instructions for general nib smoothing. Read them thoroughly before you begin. If you do, you will destroy one less pen when practicing.
Where can I get nib smoothing tools?

You don’t need many tools. Here is what I use (with the caveat that this is a steep learning curve, and you embark on it at your own risk). I have no affiliation with any of the links below, and this content is not sponsored.
- 3M Micro-mesh sanding pads, with foam backing. I use three grits: 12000, 6000, and 3600.
- Strips of wet/dry sandpaper. I use 1000 grit. This is for smoothing sharp interior corners of the tipping material.
- Brass foil, for cleaning out the slit. I often use the 0.0015″ thickness. The variety pack (listed at the link) will keep you going for a long time.
- A magnifier. What you get depends on your needs and preferences. Try to get something hands-free, like a visor. Don’t ask what I use, because it probably cost more than your car. ; )
- Mini-pliers. Only use pliers with smooth jaws, and use some of your new sandpaper to smooth the sharp edges. The best are small modelling pliers used by the mini-fig crowd (think Warhammer). You get what you pay for (a good brand is GodHand, from Japan).
- Good lighting. If you have a ring light for zoom that would work well.
Are there any secret tips that no one talks about?

It mostly has to do with experience and motor-muscle memory, which can’t really be talked about. However, I have a few pieces of advice.

First, if you have struggled for what seems like hours, and the nib is still scratchy no matter what you do, the tipping is twisted. I find this happens about half the time. This is an advanced job, not for beginners: send it away.

A Parker "51" can’t be worked on like this!

Second, a warning about hooded pens, like Parker 51s. Most nibs can be worked on while still in place on the pen. Hooded pens are the exception. If you try to work on one of these with the hood on, you will almost certainly damage the hood.

Third, super fine and flexy nibs are advanced. You need the experience of working on firm, broader nibs before tackling the subtleties of a nib that moves around while you write. And small tipping means less chance for failure, and the need for greater magnification.

In summary, nib smoothing is a challenging, but important pen repair skill. Much of that skill is learned the hard way, by practicing and absorbing collateral damage (i.e.: dead pens). But with persistence and hard work you can learn how, and never have to endure a scratchy pen again!

*To be fair, it’s more complicated than this. Gold alloys can be hardened, both in manufacture, and over time through use. But the more gold in the mix, the less hard the alloy will be. A 22k gold nib will never harden enough to be flexy, no matter what the manufacturer claims. You can’t pay enough to change the laws of physics! [Go back]
January 22, 2022