Hi Pascal, thanks for your help.

I deleted the extra plane. However, I’m confused about what to do with the rest of the naked edges. I get thousands now, when I only had a few before. Does it have to do with the model. I did many boolean unions with solids to get this shape

I’m uploading another version of the same model that has only 472 naked edges. I used the rebuild edges command for the first one and changed the tolerance back and forth from 1e-05 and 1e-03 to try to see if any of those fixed it. I think that caused more naked edges to appear.

Much appreciate itLess Naked edges.3dm (9.5 MB)

Update:

Also I noticed that when using boolean union to unite two solids I didn’t get naked edges, but if I used the shell command to remove the bottom surface which I need to do to 3D print this. Then Nakaed edges began to appear in the interior thickness of the object. So what I’m going to do is delete the inner surfaces. But see if I can offset it afterwards without getting naked edges because I need to model to be a minimum of 1/8" thickness to 3D print.

Thank you again