So, Wednesday I was pretty much out of commission and didn't get to write much with it. Yesterday, I changed inks, practicing filling while I was cleaning it out... capacity is better (she'd previously had trouble with it not holding much ink), but flow is rather irregular, especially if the pen sits for a while. While writing continuously it goes from very wet to completely dry, and then after keeping it nib-down until the nib is wet again, very wet again to dry in the space of one page.

It seems happiest right after I've cleaned it out with water, and I can usually resume interrupted flow (unless it's _really_ out of ink) by wetting the nib with water or ink. I've been using Waterman Purple and Swisher North Sea Blue; I sort of expect it to write very wet with the latter, since my other pens tend to.

So, since you have more Snorkel experience than I do... does this sound more like a problem with the pen, or a problem with the ink? When it's working well, it's a nice writer, but most of the time I'm fighting with it.

Um, you're not going to want to hear this...

But I figured out what was wrong with Merc's pen. It was one of the problems with my pen.
I'm almost sure it's the silicone sac.
Put in the new gasket (which is definitely a good thing. The old one is rock hard), but it still wasn't filling correctly. So, I swapped sac protectors/snorkel tubes with the black one, and everything squirted fine -- problem had to be in that part. So, I pulled out the snorkel tube, and the problem was obvious. Water was stuck in the silicone sac, interspersed with large air bubbles. I got a photo of it (I think); half the volume is water, and you've got big air bubble-water-another big air bubble-more water-air bubble. This was after at least three squirts -- one intentional in the pen, one unintentional in the black pen, and I accidentally squeezed it when I pulled off the sac protector, since I was expecting it to be empty. Playing around with it, I think something about the silicon makes ink stick to it in ways that it wouldn't to a rubber sac, and the ink gets stuck in there. That's why it'll start back up if she leaves it nib down for a while; it gives the ink a little time to dribble down the side. The silicone also doesn't seem to collapse as well as rubber when there's fluid inside of it.

To be honest, after playing with the sac outside of the pen, I think I'm going to go back to rubber except in pens that are prone to discoloration.

Jinnayah thinks she's figured out what went wrong. She and I both tried putting silicone sacs in the Snorkels so they'd last longer (don't like messing with those sac protectors), but... (quoting her e-mail to me, with permission):



I looked at her pic of the sac; the water was like, divided into sections inside it. It was pretty weird. Not the predicted failure with silicone either; I think we just had to try it and find out.

The pen is on its way back to me. I'll definitely check the feed like you said, but Kati switched to a rubber sac and that helped her pen, so I suspect that's what it needs.

While I'm here, tho, how should the tube feed be aligned inside the tube, out of curiosity?

that the ink sticks to the plastic of the converter rather than flowing normally, Before replacing the sac, can you first try to clean it with some mild detergent (drop of detergent in a glass of water, and fill with that)? That might also help, and would be interesting for future repairs.

My memory from other threads is that there's not pneumatic-specific silicon sacs, but one uses the closest available appropriate size (which, I guess, would be #14, as I've yet to see silicon in odd sizes). I've stuck with rubber because of concerns about adequate collapse, but I guess that's proven a mere bugbear.

But I will not use a silicone sac on either... the walls of the silicone sacs do not compress as well as standard or thin wall rubber sacs do....

See, my experience has been that that's not the problem with the silicone at all.