Interesting Blog On Why Some Twsbi's May Crack

[Tasmith]

He used Polarizers to see stresses in the TWSBI's plastic which may cause cracking.

 

I remember using this technique on clear plastic items when studying photography:

 

http://daverea.com/2015/09/twsbi-eco-won

 

I'll have to break out a couple of my Polarizers and try this myself.

[Ergative]

Wow, that's really interesting! Thank you for sharing. My 580 is going plenty strong, but it's good to know* that I can buy the Eco without worrying about cracking in the cheaper model.

 

*caveats, n=1, etc.

[trdsf]

That might explain why my 580 cracked enough to loosen the piston mechanism from the barrel while just flushing it out. I definitely wasn't overtwisting it. I was *really* disappointed; I haven't had it for six months yet.

[Driften]

Thanks for doing the test. I just ordered a clear model Eco. I was not too worried to start with, but its good to know.

[Tasmith]

I used this technique to compare the stress of a TWSBI 580 to a Pelikan M200.

 

TWSBI 580:

 

Pelikan M200:

 

[Driften]

Cool photos of the M200! Its nice to see how little stress it has compared to the 580

[Erik Dalton]

Great thread! Thank you for posting it.

[TSherbs]

Interesting.

[trdsf]

I contacted TWSBI and they're sending a replacement barrel for the cracked one, although I can't say I cared for the insinuation that I subjected it to rough treatment since according to the rep, it would take “quite some force” and that they “do not just crack”. The research above certainly suggests otherwise.

[trdsf]

Ugh. The new barrel arrived, and it's the wrong kind. I couldn't get the piston mechanism into it without destroying it. Back to the email drawing board...

[M A Porter]

TWSBI's blog does discuss the issue of cracking:

 

https://www.twsbi.com/blogs/news/18471955-quick-update

[trdsf]

I should follow up -- I have the correct barrel now, and the pen is back in action, although I wonder if that new post might have been due to one of my emails referring to "well-documented cracking issues" after his initial implication that I had mishandled the pen.

[Honeybadgers]

I should follow up -- I have the correct barrel now, and the pen is back in action, although I wonder if that new post might have been due to one of my emails referring to "well-documented cracking issues" after his initial implication that I had mishandled the pen.

 

Guessing you spoke with Philip?