Interstage fairing question

[Kelderek]

Is there any rhyme or reason for which parts can have a fairing close on them? I have a fairing that I tried to close on a whole bunch of different things and it refused to offer up the "close fairing" option for any of them. They were all 2.5m parts. I tried the ISRU, the large ore storage tank, both the 2.5m decoupler and stack separator, the smallest 2.5m fuel tank, another 2.5m fairing base, a clamp-o-tron sr., and a 3.75m heat shield. None of these would allow a fairing to close on them.

I didn't have anything obstructing the fairing for this, I was able to place cross sections all around, but I just couldn't close the fairing against any of those parts. Am I missing something here?

[kStrout]

I have never had problems with it, sometimes you need to point your mouse above where you want it to close and just experiment until you get the close fairing option. And I don't know if you know this but when closing interstage fairings they option will be blue, not green.

[DeMatt]

The ISRU and the heat shield don't permit for surface attachment, so I'm not surprised they don't permit a fairing to close on them.

I was able to get fairings to close on the other parts. Straight fairings, with no angle inwards or outwards, can close on the rims; angled fairings coming inwards can close on the sides or rims; angled fairings opening outwards can't close at all.

Beyond that, we'd have to see the fairing you're trying to build in order to replicate it.

[xtoro]

I've had fairings close on heat shields multiple times. I don't have the ISRU yet so I can't confirm that. Are you using any modded parts that you're trying to enclose?

[cybersol]

Fairing closing can be annoying to me as well. Some things I noticed are that once it goes orange it tends to stay orange, even when it would have been green if it never went orange first. Another is that sections need to be some minimum size or you can't seem to close them. Still, I spent 5 minutes once trying to get a fairing to close again at the same place it closed before after I changed something minor. After that is when I decided to test if they were even worth adding for Kerbin ascent (not really).