Concentric infill and watertight/airtight printing

[animatorgeek]

I have several projects that need to be water- or air-tight. I found an instructable that recommended MatterControl. I've been experimenting with it and I like how well-sealed the seams seem to be, but I'm trying to fix a problem with concentric infill. MatterControl seems to be ignoring the "fill thin gaps" setting. It consistently gives me something like this:

It's frustrating because all those gaps mean that fill wall will do nothing to protect against leaks. What I'd really like is for it to have an unbroken line -- just extrude a little less if there's not enough space for full width (like the "fill thin gaps" setting implies).

Here are my settings for this image:

Any advice would be appreciated.

Edit: I tried setting it to have three perimeters and got pretty much the same results:

[tinken]

@animatorgeek You could try increasing your extrusion multiplier to fill in extra gaps. Also try running a little hotter.

[fridayrack]

You could take a stab at expanding your expulsion multiplier to fill in additional holes. Likewise, take a stab at running somewhat more smoking.