Here is the 3d file. I've used some boolean steps to shape the image after doing the rail resolve (the rail is still in place for you to see). I'll try to explain this as best I can to see if I am following your logic. If I take the rail line curve that I've drawn and draw two straight lines (almost at a right angle to each other, connecting the two ends of the current rail) that would close the rail in sort of a rounded triangle shape, which would then allow me to have the rounded shape on the outside and flat surfaces on the inner sides of the shape? Hope that made sense?

I've been recreating all your tutorial work for the past few hours, plus reading the documentation in the PDF, so when I say I'm a new to this, I'm literally 5-6 hours into my learning how to 3d model.

I figure working in solid shapes will be easier for what I need, as to do the 3D printing I want, I need to have watertight models - seems to me just one wrong connection point with non-solid shapes could ruin the watertightness of the object? By combining solid shapes then using boolean union options, I should be able to combine a bunch of solid shapes with no gaps anywhere in the model...I think.

As a side note, your tutorials are really impressive - wish there were more people doing tutorials like yours. I looked a few others, but without the voice overs to actually explain what's going on, they are a bit harder to follow.

Thanks for any help you can offer Michael.

Ryan.