I'm having trouble trimming these surfaces

I have a set of vertical fins at 1.5" thick that I would like to use to cut the horizontal rings. When I try to do the solid trim component, it seems that nothing happens.2018.05.10_mcneel_forum.gh (1.5 MB)

Like this?

2018.05.10_mcneel_forum_v1.gh (1.5 MB)

Thank you!

I haven’t had the chance to open your GH file yet, but is there a reason some of the ‘shelves’ are absent in the preview image? It looks like there are two sections that are missing.

Hmmm… you are right. I have no bloody idea why…