In my demonstrator 1911M, water condenses inside the cap. I dont know what's going on. When I put it on, it seems to be dry and I screw it in relatively tight. Why is it condensing? If it were a solid color, I wouldn't care. Since its a demonstrator, it doesn't look too pleasing. Anybody know what is happening?

My guess: ink is largely water, and some of the water out of the ink in the pen/nib/feed is evaporating and condensing in the cap. What can you do? To the best of my knowledge, not much - that's part of a demonstrator. Sorry I don't have better news - perhaps someone else will.

Warming and then cooling the pen, by having it in your pocket and then taking it out, for instance, can do this.

The only time I have found condensation inside my cap or on my nib is from not
putting it in my shirt pocket and walking around at work with it my hand where my
body heat is warming up the pen causing a rainforest effect in side the cap, after
all it is humid in the pen with water being the biggest ingredient of ink.

It seems like after you put your cap on your pen it gets close enough to a heat
source; under a lamp, sunlight thru a window etc. where it can form condensation
and it only needs to be a few degrees higher than the temp of the rest of the room.

Just a thought.

Also, tightening your cap is not going to fix it. If it were the cap not being tight you
would get a dry nib or maybe a hard starter, not a wet inside cap unless it's stored
in a humidor or you take a shower with it.

Scott.

Not related to Sailor 1911, but I noticed on my demostrator Pelikans, there is condensation above where the piston converter is, even in new pens. There seems to be no way for me to take apart the pen to get the water out.

That's not condensation, that's lubricant

I get the same with both of my 1911 demonstrators. these days I tend to use a paper towel to clear it out - this also gets rid of any inks spots too (that always seem to appear).

aaah, the price of owning a demonstrator...

You guys got it exactly right...I kept the pen in a pocket close to my body, which heated it up. Anyway, I decided to sell this pen due to the M nib on it even though I absolutely love it.

Condensation occurs when reletively warm humid air (i.e. with some moisture in it, no matter how much) is brought to its dew point temperature or lower.

Keeping a pen close to the body or any heat source will warm the air inside the cap/barrel. When this pen is brought into contact with a sufficiently cold environment, a temperature gradient will develop between the warm air trapped inside the cap/barrel and the cold outside air. Condensation will occur at a point at which the temperature on this gradient passes the dew point temperature of the air inside the cap/barrel. This condensation point will be on the warm side of the system which, in the case of a pen with a relatively thin, homogenous, single-layered metal or plastic cap/barrel, is on the inside of the cap/barrel.

At a constant pressure, the likelihood of condensation occuring depends on the temperature of the air inside the cap/barrel, its moisture content, the temperature of the outside environment and the heat transfer coefficient of the cap/barrel material. Having a breathable cap/barrel can allow greater heat transfer between the inside and outside of the cap/barrel, reducing the temperature gradient. This can reduce the chance of condensation.

The problem is though, with a breathable cap, the moisture inside the cap will also escape. Over the course of a day or so, this means that the nib will dry out.

I quite agree. Also, if you tend to move from a very warm place to a very cool place often (relatively speaking), then a little breathing hole may not be enough.

Funny, though, my vintage Burnham has two holes in the cap, but the ink has never dried out. Maybe its because the feed design is different; it doesn't have fins to catch ink like modern pens and is quite flush agains the section, leaving less area for the ink to evaporate. The downside is, as we all know, it drips when you shake it!