Osmia Blind Cap Stuck

September 2, 2017

Hi All,

The crown of my collection, a 1930s Osmia Supra 76 EF, is having some trouble and I could use your help.

It worked perfectly when I bought it, but it had the originally cork on it so I filled it with distilled water and put it away for a couple months just in case the cork needed some reviving. I just took it out to use it and to my horror the blind cap won't unscrew. When I try to do so it turns the now incredibly stiff piston a little until both are totally stuck. If I try to unscrew the blind cap even more the piston makes a clicking sound but the cap just keeps turning without unscrewing. Also the water I had filled it with has vanished. Did I oversoak the cork or something?

Any help would be greatly appreciated. This is my favorite pen and an amazing writer.

Thanks!

September 3, 2017

Hi Truthpil, and sorry to hear about your Osmia 76 (I'd love to find one for myself!).

When you filled the pen w/ distilled water before you put it away, did you store it "nib-up" or on its side? If you immediately inked up the pen when you first received it, the orginal cork was (probably) partially deteriorated, so that it temporarily drew in ink, but perhaps let a bit of ink in past the seal and into the piston mechanism. Then when you filled it w/ distilled water, I wonder if that helped wash the ink even more into the piston mechanism/piston knob/blind cap interior, so that you have dried up ink acting like glue & making the threads of the blind cap stick to the threads on the end of the barrel?

Sometimes there isn't much clearance space between the inside of the blind cap and the piston knob, so when you say that turning the blind cap is also turning the piston, I also wonder if there was enough dried ink back there to bind the blind cap to the piston knob once the water had evaporated (?)
I would first try soaking the back end of the barrel in water so that the blind cap is completely submerged, in hopes of dissolving the dried ink. If you have an U/S cleaner, that may speed up the process; if not, let it soak for a 2 days... then get back to us.

September 4, 2017

Don Jr, thanks so much for your reply!

After filling the pen with distilled water, I stored the pen on its side in a pen case.

When I put ink in it, I just put in a little and when I flushed the pen there wasn't any ink behind the cork, so I think the problem has to do with the water.

Thankfully, I was able to gently get the blind cap off yesterday and could then fully operate the piston. No dried ink or water anywhere. The cork actually appears to have shrunk and moves around between the parts that hold it in place. My fear is that the water went back into the mechanism and did damage to the celluloid before it evaporated. There is no discoloration I can see on the outside, but the knob you twist to operate the piston is sticking a little further out of the back of the pen than it used to and seems to have somehow gotten just a tad wider (swollen?) as well.