Platinum Pen - Loose Cap

[stan]

Have an early 1990s Platinum 3776 on which the cap does not fit snugly. This is a slip on cap - NOT screw cap. Cap is held to pen section by friction with a plastic inner cap liner. Pen is new and never used.

 

Have seen other used models where the cap is not snug. Inside cap are three parts - metal spring band, then cap liner, then small cup to protect tassie/clip screw. Have seen other designs but, all basically the same.

 

Does anyone have experience repairing the cap or replacing the cap liner. Parts cannot be obtained from Platinum. Am confident this can be fixed. Just don't know how.

 

One method attempted was to remove the cap liner and place a thin layer of tape around the liner to narrow the liner diameter. Have not found tap thin enough to effectively make this repair.

[loganrah]

Can't help much. But if you want really thin tape teflon plumber's tape can't be beat. It isn't sticky, but if sandwhiched between the inner and outer cap it shouldn't move, and that has the advantage of meaning you can remove it in future with no fear of damage.

Edit: And a roll of plumber's tape is also a useful thing to have around in general. For pens it can be used on internal threads to help them seal well and close tightly without risk of damage or making them hard to unscrew. I recently did this on a Pilot 742 where the section and body didn't feel fully secure. A few layers of plumber's tape on the internal threads ended that problem.

Edited December 10, 2019 by loganrah

[mke]

teflon tape is a good work-around but it can sometimes be a little bit tricky to make it stay where you want it to stay

[awa54]

Hi Stan,

 

Let us know if you find a solution to this, I also have a current production "Gathered" with a little play in the snap mechanism, which leads to hard starts and eventual dry-outs.

 

The dimensions of the inner cap and clutch fingers are different on the new pen compared to my early production version (which seals perfectly).

 

I almost think that it's more of an issue with the seating depth of the inner cap (which appears to be the mechanism for the "snap in" retention of the section), if the cap was seated a quarter millimeter deeper I bet it would retain the section without any slop, as the snap interface would be under tension.

[philhygra]

I remembered I had the same problem with an early one as well. I had never even looked inside thinking it was wear, but inspired by your liner idea I looked in. With a sturdy piece of metal (I used small, narrow scissors) I lifted the inner cap liner a bit up an there it was - much tighter now. My liner is with long open cells on the walls of it and it is easy to push it up using one of those. It will probably loosen in future again...

[stan]

Thank you for the great suggestion.

 

Suggesting the inner cap should be pushed further in was counter-intuitive based on testing by inserting other Platinum pens in the same cap and measuring where the friction inside the cap occurred. It does seem to work.

 

Older Platinum pens have a flat metal piece that is below the cap liner and held in place by spring force. Pushing the cap liner up didn’t help much. Pushing this metal piece further in to be tight with the bottom of the cap liner did the trick. Whether this pushed the cap liner further in or, ever so slightly, compressed the cap liner is not known.

[awa54]

Sorry I haven't reviseted this thread or replied to your PM sooner... it's retail mayhem season (Christmas) and I've been a bit frazzled.

 

the net result of deeper inner cap seating or section shortening achieves the same end, which is forcing the cap lip to contact the barrel and thus keeping the snap lips in the inner cap tensioned against the ridged ring at the top of the section.

 

I like screw and (modern) slip caps better than snap caps in most cases.