Thank you for your responses. I have uploaded a gif of the full item in sketch-up.

You will see that I have already created the hollow tube, but when I close it, it closes all the faces and makes the object solid. Is there a way to hollow the shape and have the face closed?

I couldn't upload the video to their forum but here is a video.

Hello there. I appreciate the help.

My goal is to make a open cylinder / gun barrel/hollowed cylinder - I'm not sure how to describe it, but I will do my best.

On the cylinder, both ends of the cylinder would be closed, except on one end, there would a 25mm wide hole that goes about 75mm deep.

Think a hollow tool handle, the entire piece is closed except where the tang of the tool would be glued into. I do not want a solid handle as that would make it very heavy for casting.

The problem is every time i try to close the face, it wants to fill that space in as a solid. How do I prevent that from happening? I am hoping to modify my current file if possible.

Any help is greatly appreciated!