Platinum 3776 Briar Pen's Slip Cap Doesn't Seal Well

[beanbag]

I'll try to describe the mechanism without pictures. Inside the cap, there is a plastic inner cap starting approx 1" deep. This has tiny plastic ridges that grip a lip at the very front of the section, creating the "snap" sound and engagement that holds the cap on. However, even when the cap is engaged, it is slightly loose, and can be pulled out by about 0.5mm or so. At maximum cap insertion, the things that hit seem to be the lip of the outer cap against the front of the barrel of the pen, where it is slightly larger diameter than the section. That plastic inner cap doesn't seem to have any actual sealing surfaces.

 

Anyway, as a result of this, the cap does not seal well at all and the pen dries out easily. I tried (gently) pushing the plastic inner cap further in, but it didn't move. (And even if it did, I don't think the barrel-to-cap-lip seal is a good one anyway).

 

Any suggestions on how to improve the sealing on this pen?

Edited January 4, 2017 by beanbag

[Witsius]

I don't think you can improve this. Sounds like you should contact Platinum and inquire as to whether they can replace the cap under warranty. The inner cap could be cracked. That is often the cause of failure on slip caps.

[readytotalk]

Well, I`ve seen 3 briar pens from Platinum, and all of them have had the same symptom.

Seems that inner plastic cap is mounted a bit closer to the cap entrance (or maybe its too long), so after 'snap' sound section can be pulled out a bit.

Maybe it was made to ensure that section lip will be behind 'tiny lips' after insertion..

The sealing was improoved after holding the cap in hot water (70C) for 10-15 seconds, so the PVC inner cap shrunk a bit.

Edited February 14, 2019 by readytotalk