Nib damage - a theory

[Texatdurango]

Recently there has been a fair amount of discussion as to what is causing the scratches on several brands of pen nibs.

Before retiring I was a manufacturing engineer at an aerospace company and in that capacity, one of my most common tasks was to solve problems involving tooling and it’s interaction with production parts.

Well, I put that hat back on for a bit this morning and I think I have found a possible cause for the nib scratching.

To begin with, to get a cross section of several brands/vendors I took out six pens:
Baron
Jr Statesman
Majestic
Jr Gent
Baron
Emperor

Keeping vendors out of the situation (and hopefully out of the discussion) I listed only the kits which are familiar to most.

I have three photos below with captions above each. Please read and feel free to reply with any thoughts or theories but PLEASE keep the vendor and manufacturer trashing out of the discussion and focus on the problem and solution. This is my opinion only, yours may vary.

This photo shows all six caps involved and all six have at least two things in common:
1. They all have plastic threads in the cap.

2. They all have a metal center band at the mating end of the cap.

This photo shows how all six pens look just after disengaging from the lower body threads. Please note the position where the cap is contacting the nib. Does the area of contact look familiar to the scratch patterns seen on many of your nibs?

This is a close up of the center band making contact with the nib. I believe this center band is what is causing many if not all of the scratch patterns on the nibs. Under magnification, I looked at a couple caps and some show small nicks on the rim. The metal band itself could cause the scratches but in conjunction with these small nicks, when engaging and disengaging the cap from the pen, especially if a slight swirling action is present, act like small files cutting away at the nib. I believe this is why some users report little to no damage while others report more damage.

In conclusion I believe there are two culprits involved here, one is shown in the photo, and the other is reading this post!

 

[ed4copies]

I'll have you know I was no where near the location where the incident took place!!!

Looks like an interesting (and supportable) theory, Texy!!!

Do you propose a solution? Remedy? (Cut off users' fingers is probably NOT a good one) Blunt the centerband ring?

Or, were you the problem "spotter" who then passed it along to the problem "analyst(s)"?? If a government job, how large WAS the army of analysts??

Seriously, thanks George - worth looking into!

 

[1080Wayne]

From one culprit to another - Excellent analysis . Solution ??

 

[gwilki]

I resemble that remark, Ed. I work for the government and I figured this out on my own.

Seriously, I think George is spot on. I posted on this subject in the fountain pen forum, with a similar take. Of course, I didn't take all the pics that George did, so I was just goofing around.

I was actually able to get scratching on an El Grande plastic section, caused by the plastic threads inside the cap - no metal contact at all. I think the root cause there is pilot error. Even plastic threads can scratch if they meet the section at a sharp angle and the cap is being turned at the same time. There is almost a shearing action going on, I believe.

When you think of it, this is not far fetched. I can scratch lexan or acrylic easily with a plastic ice scraper. Been there, done that.

 

[Texatdurango]

Fellow culprits,

Ed, I'm going to use regular sized fonts and colors now that I know you CAN read normal text when you want or have too!

I am inclined to get one of my slightly curved fine jewelers files and lightly break the sharp edge on the inside ridge of the center band. But, I haven't noticed the swirls others have so I may not be a candidate to test the theory on. In the real world, I believe some users cap their pens with a more deliberate straight on approach than others who come at it with a slight angle, not even realizing what they are doing since the angle is so slight. Since using fountain pens, I have become more of the straight in type since I don't want to take a chance and grab the fountain nib on something.

Perhaps if everyone pretended they had 18k gold fountain nibs in their pens and were more deliberate about capping and uncapping, the problem might go away. Note I said might!

 

[ed4copies]

Thanks for thinking of me "font-wise", Tex.

I have found Firefox can change size of type "on the fly". So, its Ctrl++ for me, now!!!

 

[Rmartin]

Excellent post and analysis

Thanks

 

[redfishsc]

Looking at your pics I see exactly what you're talking about. The scuff marks on the Jr GentII I mentioned are confined to one ring right in the center (sorry I don't have pic of it at the moment). These pen caps have the tendency to unscrew in my shirt pocket, which may cause the metal part you are pointing at to routinely scuff the same spot.

Strangely that's something I LOVE about the El Grande/Churchills, the caps thread on a good bit more snug than do the Barons and Gents/Jr Gents. If we could carry that same characteristic over to the Baron/Gent styles we'd have a real winner.


Thanks for the work George. This is one problem I should not have chalked up to mfr. error.

 

[Paul in OKC]

Roy and I were able to discuss some of this over lunch today. Just what we came up with, basically operator error.

 

[Chuck Key]

Originally posted by ed4copies

type "on the fly". So, its Ctrl++ for me, now!!!

Ed, please stop typing that, it gets my computer all excited.

George: When will the price of gas go down?

 

[Texatdurango]

Originally posted by redfishsc

....
Strangely that's something I LOVE about the El Grande/Churchills, the caps thread on a good bit more snug than do the Barons and Gents/Jr Gents. If we could carry that same characteristic over to the Baron/Gent styles we'd have a real winner.

True! When I started making my own pens recently and cutting my own threads I have yet to have one pen unscrew in my pocket. Sadly I cannot say the same thing for the Jr Gent I carry everywhere. My wife says "one more pocket leak and I'll hide your fountain pens" to which I replied "FINE, I'll just make more!"

We're sorta at an impass on that!

 

[marcruby]

This makes sense. The preventative would be some fine polishing of the offending parts. Shouldn't be too hard to accomplish.

Marc

 

[Texatdurango]

Originally posted by Chuck Key

...George: When will the price of gas go down?

Beats me, we're less than a month away from embarking on a 6k mile trip getting 10mpg using diesel so I figure fuel prices will drop some time in late September, right after we return home![:0]

 

[Texatdurango]

Originally posted by marcruby

This makes sense. The preventative would be some fine polishing of the offending parts. Shouldn't be too hard to accomplish.

Marc

That gives me an idea! Let's see, where is my Dremel tool!

 

[LostintheWoods]

Just what I was thinking, Tex. The Dremel with the little "Christmas-Tree"-shaped buffing tip, along with maybe White Diamond, should pretty much suffice, doncha think?

 

[redfishsc]

True! When I started making my own pens recently and cutting my own threads I have yet to have one pen unscrew in my pocket. Sadly I cannot say the same thing for the Jr Gent I carry everywhere. My wife says "one more pocket leak and I'll hide your fountain pens" to which I replied "FINE, I'll just make more!"

We're sorta at an impass on that!

Does the CSA Ligero rollerball have the same nice thread feature as the El Grande?

 

[OKLAHOMAN]

Paul and I did discuss this today and we both felt that it had to be operator error and you showed how the error could occur with pictures, thanks.

 

[redfishsc]

As a side note, since the problem seems to have been found, I'm still hesitant to call it solely an operator error.

If George is right and the sharper edges inside the centerband are the culprit, then the problem would not happen if the inner edges were softer or not raspy. It's not like we're doing anything outright wrong (nor can we help much that the caps come unscrewed in our pockets, which is when mine get damaged).

I'll be buffing this inner ring smoother from now one, I may see if a small conical chucking reamer, or even 1000 grit s/c sandpaper contact-glued to a wooden cone would help to break that edge.

 

[brez]

George,

What kind of Baron is that in your photo with a green stripe on the center band?

Thanks
Mike

 

[johncrane]

Redfish l would not be grinding the inner center ring just yet.As l could not get my pen too touch the inner center ring where my damage is,The only place it touched first was at the nib threads.l did this under a magnifier glass!so l don't think this is over yet. Also George if you have some unmade JR series and Jr Statesman kits check out the different length's of the plastic threads l found the longer thread in the JR Statesman to be more stable when turning the finger grip on the threads.However The Jr series plastic thread is a much smaller in length and has more slop in it and l could get it too rub on the finger grip where my damage is.Also the Jr Statesman f/pen has a two piece plastic thread, in the JR statesman roller ball it has a one piece plastic thread and has the least movement now has any one had problems with Jr Statesman.

 

[Texatdurango]

Originally posted by brez

George,

What kind of Baron is that in your photo with a green stripe on the center band?

Thanks
Mike

That my friend is a Wayne Swindlehurst pen!

I lucked out and drew Wayne in a pen swap last year and this is my prize.

I got two really nice pens from pen swaps last year. One sits in my desktop 12 pen carousel along with my favorite fountain pens and is used frequently and the other goes with me everywhere I go and is my "daily use" pen.

Wayne removed the kit center band center piece and fashioned a tiny ring from a piece of green acrylic. Talk about talent... and not wasting antyhing! I'll be years learning little tips like this from some of the pen masters around here!

Actually the other swap pen, which can be seen in the close up view on the front page, is one of the pens I carry around every day and was crafted by Gary Nicholls last year.

 

[Texatdurango]

John, I looked around at several cap interiors and see what you are talking about but discounted that edge since I didn't see any interference with the nib. With mine, the only thing that came close to the upper plastic serface was the fountain nib itself. Look inside that Jr Statesman section and tell me if you see a ridge just above the threads. I didn't see that earlier and that looks like something that could do some rubbing.

We're gonna keep plinking away at this and stumble onto the causes of all these scratches yet! Could be a combination of several things.

 

[el_d]

Im with John and Matt on this one, but I dont know im a culprit thats too stupid to cap a pen.
The damage I see is about 15mm away from the base on both ends of the Jr Gent. The longer "grip" and the shorter "postable end". If there was a problem inserting a pen at an angle, wouldnt the damage be respective to the length of the end? I could see the verticle scrathes being made on the grip by angle of insertion but how are the perfectly worn thread patterns "operator error"? I know im not that perfect and could not get the same wear pattern every single time.

 

[Randy_]

Nice theory and well worth examining; but I'm not totally convinced.

I don't know about others; but I can tell when the cap threads and barrel threads are engaged or disengaged and quit twisting the cap at the appropriate time. There is no rotational component to the cap motion except when the threads are in contact.

It seems to me that if the damage is caused by the cap being held at an angle during the capping/uncapping process as postulated, one might expect the scratch pattern to be parallel to the long axis of the pen rather than perpendicular to it.

Another question that occurs to me is the following. This discussion originated over a question about a Majestic kit which is a relatively new design; but there have also been some comments that similar problems are seen in kits that have been around for a while. So the question is whether this problem is a new one that is just making itself known or whether it is a problem that has existed for some time; but never reported before?

 

[johncrane]

l will try to explain what l found today looking at 4 JR kits
first l joined nib to the nib coupler, then l joined the nib coupler
to the center band coupler which has the plastic threads, the parts where all done up firm.next l held the plastic thread end in my left hand,and with the right hand l tried to move the nip end, 3 had no movement,one did have movement' Next l backed off the nib coupler maybe 1/8th of a turn, just off the firm side,l then done the same test as before l griped the plastic treads left hand, and the nib end in my right hand, now holding the left hand firm, l found l could move the nib end up and down to the sides rubbing the threads onto the finger grip. The JR Statesman R/ball was good not hitting until it was nearly clear of all the threads.the longer plastic coupler is a big improvement over the smaller one's.
next JR Statesman Fountain pen l thought was better than the last two.
having the extra length of plastic,
next Jr gents with the short plastic threads clearly hits the nib holder or finger grip with just a small amount of turn to get it to hit'JR Retro was at the bottom! what can l say test this one your self.
So out of my testing for what it's worth l think the rubbing is happening as soon as you move the cap you can clearly see this with a unmade kit. also try too keep your pen straight when capping/uncapping and as for Rhodium plating, Well' l will leave that one up too the experts, l also think once you get metal on your threads it will cause more drama so try to keep your threads clean.

 

[el_d]

By George Inspector Crane I think you'v got it!!!!
Now Im really weary about using my Copper Jr. Gent.

 

[Randy_]

OK, folks....how about something else to think about.

First off, if you have to keep a pen meticulously clean and align the cap and barrel perfectly when capping and uncapping, and have to grind off/polish rough/sharp edges to to keep the pen from damaging its own nib plating, I question whether that is operator error, especially since there are no warnings that I recall in any of the instruction sheets about such difficulties. Seems to me it equally fair, even proper, to identify these issues as design flaws. But we can discuss that in another thread if anyone is of a mind

The point I would really like for folks to home in on is the possibility that there is more than one cause for the damage to the plating, that different kits may have different problems and require different solutions and that a single kit design could have more than one problem.

I did the same as John and unpackaged two unassembled kits that I had available and took a close (20x loupe) at them to see what I could discover. One kit was a Jr. Gent Ver. I GTn rollerball and the other was a Jr. Statesman Ver. I FP Plat. From the pictures that John posted, it appears that the my hardware and his are identical so we should be comparing apples and apples. Let me say, first off, that I tried John's "wiggle" test and found a totally different result. The threads on my kit were very snug and I detected no wiggle whatsoever, even after loosening the nib more than a 1/4 turn. Can't say whether tight threads like mine are the norm; but it might be possible that loosely cut threads could be a problem??

Next, I tried George's test of canting the "cap threads" relative to the nib threads and just couldn't make that work under "normal" conditions. Perhaps someone with a heavy hand and a careless touch could do some damage; but it is hard for me to see the "normal pen" owner damaging his pen in that fashion. That being said, this is not a problem that crops up every day of the week so maybe there are a few Frankenpen owners out there who are "abusing" their pens and causing damage in this fashion.

Now for my interesting discovery!! I noticed that when the nib of my Jr. Gent was fully screwed into the CB coupler, the nib partially touched the plastic end of the CB coupler. The nib of the Jr. Statesman kit, on the other hand, was perfectly concentric with the hole in the plastic thread insert and did not touch it at any point. Clearance was less than 1/2 mm; but "THERE WAS NO CONTACT BETWEEN THE NIB AND THE THREAD INSERT."

Every time I screwed the Jr. Gent nib in or out it rubbed against the inside of the plastic end of the CB coupler and always touched in the same spot on the nib. The thread on this CB is a four lead thread so it it possible that there are four different radial spots on the nib that might rub on the plastic insert; but that is a little tricky to check accurately and I don't have time to mess with it right now. For those of you have followed me to this point, I expect you can see where I am going. If you live in West Texas where the wind is always blowing up dust or you work in a dusty shop environment or leave your pen to roll around in the bottom of a less than pristine hand bag or are just plain unlucky, a few specks of sand or dust embedded in the plastic end of that
coupler would not be a whole bunch different than putting your nib on the lathe and hitting it with some 600 grit W/D sandpaper.....bye, bye plating. Of course, it would take a lot longer for the plating to be damaged if you are talking about only a few pieces of girt twisted into your nib plating once or twice or three times a day; but the long term net result would be the same.....bye, bye plating. And one last interesting coincidence.......I measured the distance from the threaded end of the nib to the spot where the contact was occurring. Turned out to be about 15mm!! Not where Lupe said he was seeing damage on his pen in the preceding post.

I can't say for sure that what I saw on my Jr. Gent is the cause of problems others are seeing or even if my pen would have a problem if it got dirty; but it is certainly another possibility that needs to be examined. When I get a few minutes, I'm going to look more closely and compare the Jr. Gent to the Jr. Statesman and see if I can figure out why one rubs and the other does not. Several possibilities.....CB threads not cut correctly. nib coupler threads not cut correctly, CB plastic insert bore not concentric and maybe others.

I also need to refresh my memory on another issue. I seem to recall that either the JRs or the big boys (Gents and Statesmans) had a problem with the threading engaging properly and CSUSA had to redesign the CB plastic insert to solve the problem. Don't know if this has any bearing on the current discussion; but it is worth looking into.

And just to reiterate, let's not get locked into a pattern of thinking that there is a one size fits all solution to this problem. Let's try to look at all of the possibilities as there may well be more than one.

 

[redfishsc]

I keep looking at the JR GentII FP I have that has the damage, and I don't think the sharper edge of the center band is touching, as someone in this thread suggested. I read the post and went and looked at mine, and even if I TRY to force it ****-eyed, the cb does not touch the nib holder.

So if that's not the problem, geeeze, what is? I don't see how plastic threads and parts will scuff metal plating like that. Makes no sense to me.