Clear, Demonstrator Pens More Prone To Cracking?

[Ron Z]

The second "I" went on vacation until Labor Day.

[sirgilbert357]

Well, I just got a TWSBI Mini Classic and have been loving it. I'll be careful with it, but TWSBI's customer service is excellent, so I'm not really that worried about it...no cracks yet...

[NewPenMan]

I am glad to hear that enjoy your pen!!

[sirgilbert357]

I am glad to hear that enjoy your pen!!

Thanks! It has a lot to do with the 1.1 mm italic nib I think.

[NewPenMan]

one day, I'll treat myself to one of those nibs!

[ac12]

I used a clear Sheaffer School Pen in grade school, and I had to have been hard on it. And it stood up to me, until I lost it.

 

My green TWSBI 530 has been just fine, as has my clear Pelikan M200.

I just picked up a TWSBI Eco, so that will be going through the paces here very soon.

[catbert]

Interesting method to assess the likelihood of cracking.

 

The Polarizing Truth: Why Your TWSBI Eco Won't Break

[FOUR X FOUR]

I'll just say this, if TWSBI has a problem with Crack he should get help. In the immortal words of Whitney Houston

"Crack is whack"

[FOUR X FOUR]

I might be wrong but I think just the opposite is closer to the truth. Two comparable plastics, one being clear, I think would be more durable than the one that had stuff/colorant added to give it color or make it opaque.As far as TWSBI goes. I have around 8 different ones. None of them have ever cracked. I'm also very delicate with my pens, the climate in my home is cool and the humidity is low. I absolutely believe the horror stories about folks TWSBIs breaking. I don't fully tighten mine down. I've two different pens break on me. The first one was the Conklin Mark Twain demonstrator. That whole pen fell apart. The next pen that broke on me was my Pilot custom heritage 92. It developed a crack in the barrel. Pilot replaced the entire pen. The pen that they sent me, the cap broke. This one, I should have in a few days. If you don't own a TWSBI and are concerned, bite the bullet and go get that vac 700. My only advise is, don't torque down the cap. Seriously, don't torque down the cap.

Just a little advise from your uncle Allan

[Drone]

Interesting method to assess the likelihood of cracking.

 

The Polarizing Truth: Why Your TWSBI Eco Won't Break

 

Thanks for posting this link - it is a very interesting article.

 

TL;DR Engineer and FP User Dave Rea looks at internal stresses in the TWSBI 580 vs. ECO using polarized light.

[Precise]

https://www.fountainpennetwork.com/forum/topic/297539-what-are-the-best-clear-demonstrator-pens-ever-made/?p=3463718

 

https://www.fountainpennetwork.com/forum/topic/297539-what-are-the-best-clear-demonstrator-pens-ever-made/?p=3464051

 

https://www.fountainpennetwork.com/forum/topic/297539-what-are-the-best-clear-demonstrator-pens-ever-made/?p=3464278

[PrestoTenebroso]

jar "Sheaffer used a transparent plastic in their first three iterations of the cartridge "School Pen" and I have several that are well over a half century old now and none have cracked."

 

thanks for the reminder.. these in every color along with clear where my first self-directed purchases as a child. I vaguely recall one being smashed, but that was more a mission of kid wars, sort of like the FPN Lamy2k torture test, not Sheaffer plastic failure.

 

curious.. (in a well-wishing manner), we have engineers, machinists of all sorts here. what's your take on this issue? Twisbi is certainly, from the get go, full-fledged Trying to develop something special, reliable, fulfill the wishes of the pen community, while backing their product through the issues. Were there more stable materials, design, and molding practices of the past that they're not quite capturing with regard to this cracked plastic issue?

 

If someone told me their pen cracked, the first thing I need to know is "how". I've seen non-fountain pen users and some regular fountain pen users crank down threaded parts with an alarming amount of force. I've seem them roughly post pens that really aren't meant to be posted.

 

Basically, I've seen many people treat anything with threads with the same kind of force used on nuts and bolts to hold cars together, and anything that has a slip fit gets hammered into place like they're nailing a roof to a house.

 

I have no idea what's going on; I think some of what's going on is probably user error, but I think a fair amount also has to do with pen in question not being able to live up to the amount of roughhousing that a user intuitively believes is necessary to fulfill the purposes of the design.

 

That's the only type of evidence available, pro or con. Twsbi have acknowledged the issues, so it isn't some ugly rumor being spread. The are plenty of reports of twsbi pens with cracks in them regardless of how many pens are sold m. The issue is the cracking problem. .

 

To my knowledge, nobody is ranting that the pens are transparent and show the ink inside, but that the twsbi pens crack and this for a fountain pen, is a deal-breaker problem.

 

I don't have hard numbers on this but what I have heard and read is keeping me from buying twsbi pens.

Rumors kill! But specifically, how is it happening?

 

 

Not just young companies and not just when they are starting out.

 

Around Christmas of 1939 Waterman introduced a flagship pen using the new material Lucite called the 100 Year pen.

 

http://www.fototime.com/34A52EA1BD18493/large.jpg

Unfortunately many of the ends began cracking, crazing, getting milky and crumbling away. Today a 100Year pen that has not had the end replaced is somewhat rare.

 

Sheaffer made their plunger filler pens with a steel rod that was coated in plastic to protect it. Unfortunately the plastic often cracked allowing ink to eat away the rod.

 

Parker introduced a great new product (and Scripto about the same time), a liquid graphite pencil that could be erased but still be as permanent as any pencil. While the two pencils were initially popular sales dwindled and within five years or so the products were discontinued.

 

Montblanc introduced a new and for them very innovative model, the 250 series with a new wing nib and a slip on cap.

 

http://www.fototime.com/4D404D7D012C8F0/large.jpg

It was and still is an exceptional pen but it suffered from stress cracks in the cap lips. Today finding one without cracks is difficult.

 

Montblanc also had problems with something as simple as naming their pens. They tried to call their flagship 149 "The Diplomat" even though there was and still is an existing German Diplomat fountain pen company. They introduced a line of compact pens called "Rouge et Noir" and "Noir et Noir" even though the names "et Noir" were trademarked in Germany. In both cases they were sued, lost and had to stop using the names.

 

Omas had a whole series of pens where the celluloid was not cured sufficiently and so failed.

 

Casein was a popular material for pens but had one serious drawback. When exposed to water it would absorb the water and swell up, eventually dissolving.

 

The lesson is that if you are uncomfortable with a product and worry that the product will fail, then just don't buy that product.

Excellent point. Thanks for reminding us that even the "pros" have less-than-ideal products sometimes.

 

I'll just say this, if TWSBI has a problem with Crack he should get help. In the immortal words of Whitney Houston

"Crack is whack"

R.I.P pre-Bobby Brown Whitney.

 

I might be wrong but I think just the opposite is closer to the truth. Two comparable plastics, one being clear, I think would be more durable than the one that had stuff/colorant added to give it color or make it opaque.As far as TWSBI goes. I have around 8 different ones. None of them have ever cracked. I'm also very delicate with my pens, the climate in my home is cool and the humidity is low. I absolutely believe the horror stories about folks TWSBIs breaking. I don't fully tighten mine down. I've two different pens break on me. The first one was the Conklin Mark Twain demonstrator. That whole pen fell apart. The next pen that broke on me was my Pilot custom heritage 92. It developed a crack in the barrel. Pilot replaced the entire pen. The pen that they sent me, the cap broke. This one, I should have in a few days. If you don't own a TWSBI and are concerned, bite the bullet and go get that vac 700. My only advise is, don't torque down the cap. Seriously, don't torque down the cap.

Just a little advise from your uncle Allanimage.jpg

Cap torque. That's one data point. Remember, the purpose of threaded parts is to provide enough tension to hold the joint together, not to squeeze the last air molecule out. That's a rookie mistake made in machine shops everywhere, using more force than needed on threaded parts. The threads themselves are the strength. You don't need to be the strength.

[Precise]

Did the polycarbonate TWSBI pens break, or did they develop cracks, yet remain in one piece?

[Precise]

Incidentally, Nylon is a tough plastic which absorbs water. It does not dissolve or disintegrate but it does swell when it absorbs water. It can even swell from exposure to humidity. We're talking perhaps 1% to 10% moisture absorption. When swelled, caps, feeds, pistons, etc would not fit correctly. The grade of nylon that swells is opaque.

 

There is also a very expensive grade of transparent nylon made in Switzerland which is not troubled by moisture.

 

Alan

Edited September 29, 2015 by Precise

[Precise]

Regarding stresses molded into plastic pen parts. This should not be viewed as blanket condemnation of injection molded pen parts. It is possible to mold with low stress. Look around your house. Almost every plastic part there was injection molded. Many of them encounter much greater loads than your fountain pen, yet very few of them fail due to molded-in stress.

Edited September 29, 2015 by Precise

[Drone]

Incidentally, Nylon is a tough plastic which absorbs water. It does not dissolve or disintegrate but it does swell when it absorbs water. It can even swell from exposure to humidity. We're talking perhaps 1% to 10% moisture absorption. When swelled, caps, feeds, pistons, etc would not fit correctly. The grade of nylon that swells is opaque.

 

There is also a very expensive grade of transparent nylon made in Switzerland which is not troubled by moisture.

 

Alan

 

Hi Alan,

 

Nylon does indeed absorb water. I remember when I was a kid boiling virgin white nylon model airplane propellers in a mixture of water and food coloring dye to tint them. Probably a dumb idea in retrospect. But in-practice the propellers worked fine. After boiling the propellers bolted onto the engine shafts as before. So there wasn't a large amount of swelling.

 

I think the transparent nylon material you are referring to is termed "Grilamid TR" by EMS-Chemie AG/EMS-Grivory. Grilamid TR does absorb water; according to the MDS about 3% in a saturated room temperature environment. I remember seeing this material referenced a while back in an online discussion thread somewhere about making transparent drone propellers and other parts for stealthiness.

 

I wonder how much the cracking of polycarbonate materials used in the TWSBI pens (if in-fact they are polycarbonate) is due to Environmental Stress Cracking (ESC); possibly because of contact with solutes in ink?

 

Regards, David

[Precise]

My reason for asking if the polycarbonate parts broke or just developed cracks, is that I've seen fine cracks in polycarbonate from exposure to hot water. But the parts I saw did not break apart. Polycarbonate was very common for sports water bottles until concerns developed about BPA. Now the same bottles are usually molded with Tritan, copolyester, which has no BPA, but can still develop the fine cracks.

[Megaloblatta]

My reason for asking if the polycarbonate parts broke or just developed cracks, is that I've seen fine cracks in polycarbonate from exposure to hot water. But the parts I saw did not break apart. Polycarbonate was very common for sports water bottles until concerns developed about BPA. Now the same bottles are usually molded with Tritan, copolyester, which has no BPA, but can still develop the fine cracks.

My TWSBI 540 developed cracks in the grip section, barrel and cap threads (and I have always been gentle with the pen). A small section of the threads fell out and then a few weeks later the barrel cracked suddenly above the metal band when I was putting the cap back on. It cracked into two pieces, which was a bit awkward as I was in a difficult work meeting and everyone saw what happened! After the meeting I had to find an elastic band and piece of plastic bag to hold the broken barrel together, otherwise I couldn't have carried the pen back without the nib getting damaged. I guess the cracks in the cap threads suddenly propogated upwards and spread in a circle around the metal cap band.

Edited October 2, 2015 by Megaloblatta

[Megaloblatta]

Below is a photo of the cracks in the cap threads of my TWSBI 540. TWSBI replaced the cap, but who know how long it will last! At least TWSBI say they guarantee their pens for life, which is more than can be said of other manufacturers e.g. Pilot. I have seen reports from people who have had cracks develop in their Pilot 823s after their three year guarantee has expired being charged hundreds of dollars to have their pens repaired...

Edited October 2, 2015 by Megaloblatta