Sheet metal from converted entities incosistent boundary location?

Hello, I am trying to create a sheet metal part in context. I have two existing parts, both cylinders, mated a specified distance apart. I want to make a sheet metal C shape that will be flush with both surfaces. Actually I want two of these parts, essentially mirror images. For each of them, I made a sketch and converted the surfaces I want the sheet metal flush with, and created a C from there. The problem is that one of them puts the sheet metal inside the C, and the other puts the sheet metal outside the C. The only difference I can tell is that the C is facing the opposite direction. This seems like very odd behavior, and I'm trying to figure out how to control it manually (I want them to both be inside the C). This must all be very confusing in words, so I'm attaching screenshots of both parts.

When the line faces to the right, solidworks does what I want. When it faces to the left, it doesn't do what I want. How do I fix this?

Thanks

EDITED BY MODERATOR: Move to the Sheet Metal space. Please post in the appropriate space when one exists.

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