Replacement Inner Cap Material For Celluloid Pens

[Bristol24]

I have accumulated several third tier celluloid fountain pens and "combo" fountain pen/pencils. Nearly all of them are missing the inner cap. Some of these pens and combos are really quite nice both in looks and in writing performance but they do tend to dry out quickly (some more than others). Being one who likes to use my vintage pens on a regular basis, I want to get each pen to the point where I have reasonable insurance that uncapping a nice looking 1930s Wearever Combo to write something down at the bank or some other public place does not have me shaking the pen to get it started. I think a proper inner cap would certainly lengthen the dry-out time of a capped nib.

 

The materials used for inner caps in many of the tier 3 pens back in the 1930s were quite cheap with laminated paper tube being quite common. Obviously, once the paper tube was really saturated with ink, it would begin to come apart and eventually be lost. I don't have a lathe and have focused on using some sort of tubing but am concerned about possible negative interactions between modern-day plastics and 1930s celluloid. I would appreciate any guidance those of you with far more experience might be able to offer. One possible material that occurred to me the other day is hardwood dowel of the proper outside diameter cut to length and drilled to accept the nib. This could then be either sealed with perhaps Thompson's water seal (on the inside only) or shellac and just left unfinished on its outside where it touches the pen's cap. Ideas and suggestions?

 

Thanks,

 

Cliff

[Ron Z]

Many 3rd tier pens didn't (and don't) have inner caps.

 

Hard rubber and Delrin rod are readily available. I wouldn't use wood because it will soak up the ink and will rod - and will crack. Parker used wood for the inside end of the inner caps on the Parkette pens, but there was still a bit of hard rubber at the open end.

 

I don't think you'd have any problems if you used acrylic though. But I think that Delrin would be best. You might try some of the white styrene tubing used in model making. You're going to have a hard time boring straight down the middle of anything without a lathe.

[Bristol24]

Many 3rd tier pens didn't (and don't) have inner caps.

 

Hard rubber and Delrin rod are readily available. I wouldn't use wood because it will soak up the ink and will rod - and will crack. Parker used wood for the inside end of the inner caps on the Parkette pens, but there was still a bit of hard rubber at the open end.

 

I don't think you'd have any problems if you used acrylic though. But I think that Delrin would be best. You might try some of the white styrene tubing used in model making. You're going to have a hard time boring straight down the middle of anything without a lathe.

Thank you for the suggestions and you are absolutely right. It would be very difficult to bore a hole straight down the middle of a rod without a lathe which is why my first focus was on tubing. Based on your comments, I may look into the styrene tubing idea. The end of the tubing could be blocked off and made airtight with epoxy. My experience with epoxy is that once cured it is pretty much a forgiving material and does not give off a noticeable smell so I would assume it would not emit a gas that would be harmful to celluloid. Would I be correct in the assumption that styrene would probably be safe with celluloid?

 

Cliff

[BamaPen]

I have encountered the same problem and have successfully used the white styrene tubing available at model/hobby shops. Since caps are usually tapered at least a little, I just chuck a piece of the tubing in a drill and use sandpaper to shape it to fit. Then I cut it to the right length and slip it in place. Depending on the cap, you may want to add a bit of styrene, sheet material will work, across the top end to seal it. I have done this with caps that have a Z clip, which is held in place by the inner cap, and it seems to work fine. And the price is right!

[Ron Z]

Many inner caps are not sealed at the inside end. Not ideal, but common on modern pens as well as vintage.

[Bristol24]

Well, I have to say that the styrene tube idea has captured my imagination. A power drill together with sandpaper or a file can function as a handy substitute for a lathe. As to sealing the end of the inner cap, my thinking is "in for a penny, in for a pound." The smaller one can make the space occupied by the nib within the inner cap, the better...I would think. Thanks, Ron and BammaPen. I'm now inspired.

 

Cliff

[Ron Z]

 

 

A power drill together with sandpaper or a file can function as a handy substitute for a lathe.

 

A couple of decades ago, before I got a lathe, I used to turn Esterbrook buttons on a 1/2" in slow speed drill with the handle clamped in a vise, using wood carving tools to shave the plastic down. It has been referred to as a poor man's lathe.