Is a Parker "demi size" Vacumatic supposed to post?

[Doc4]

I bought one recently ... very nice pen (and lighter than I expected.) It writes well. (It goes from about an "F" to at least a "M" with just a bit of pressure.)

Anyhow, the cap won't post.

Is this normal/expected for a pen like this. It's a small pen, so posting would be a distinct advantage.

[Blue-EyedSon]

Nice vac!

All of my mine post without trouble. I'm not sure if any are technically the 'demi' size as the sizing system confuses me and I haven't worried too much about figuring it out. That said, I've got some that are significantly smaller than the regular ones and I'd guess they are 'demi' sized. They post fine.

Can you tell if there is a bulge in the barrel near where the fill unit enters it? They can be overtightened, which can cause bulging and I would imagine that it could make posting difficult.

[Doc4]

Can you tell if there is a bulge in the barrel near where the fill unit enters it? They can be overtightened, which can cause bulging and I would imagine that it could make posting difficult.

No bulging that I can detect.

If I take off the back-end cap (or whatever you call it) so the filling button is exposed like in the photo above, the cap will post on the pen. But when the end cap is screwed back on, the pen won't post. Maybe a "regular" butt-cap got put on by mistake?

[nemo]

Yes they should post. Check for the bulging Brian refers to (common) and if so, take a good last look at the imprint because you're going to sand it down. Time to do a little bodywork.

Actually there are some tricks to get it to post.

We posted about the same time, so on edit, I don't think the blind caps are that much different. I took four demis, two double jewel and two single jewel models and switched all their parts around and still all posted fine. Could be something with the inner cap dimensions and there have been known issues with vac celluloid shrinkage.

Is there any visible misalignment of the blind cap/barrel interface?

[Doc4]

Time to do a little bodywork.

Can I borrow a grinder?