Blender 2.81 hollow model for 3D printing So I am playing around with Blender and it's wonderful.
Great software, very intuitive but complex.

Basically, I create a shape, a box, a toroid, a cylinder. I perform some simple deforms, stretch and twist it a bit and I use the 'screw' modifier.

GREAT!



Now I'd really like to print this shell.

I use the slicing software but it's full of internal geometry.

THE QUESTION:

Are there any actions I can perform to slice this thing up into pieces, select the outer shell and copy it, or delete everything internal that is not visible?

I'm not the only one asking and there has to be a simple way to do this, I am very sure.

We 3D-print people are desperately looking for a way to intuitively create some shape and just print the outer shell, what's visible.

THE PERFECT SOLUTION:

That would really be a button that says: 'extract exterior' or 'copy exterior' or just any way to select the outer shell.

This object is just a bunch of faces and the slicing software does a perfect job with this model, all that's in the way of printing it is all of the internal geometry.

I have performed this action of removing all internal geometry on another model I downloaded but it was already chopped into separate vertices I could remove.

The problem really is that the exterior is connected to the interior so I'm really looking for an easy way to deconnect that and seperate the external from the internal..

Thank you in advance.
There are a few solutions that I use.

1) booleans - if the models is without errors like double faces etc. and the boolean works, just make union and then triangulate faces to avoid necessary ngons

2) I used external software meshmixer, its free and have some great functions for this purpose like solidify, which takes all the geometry and create just the "visible" part as the one solid object, then there is possibility to hollow it to make it like vase with certain wall thickness.

3) Voxel remesh - after blender introduced voxel remesh I stopped using meshmixer. You just join the object in blender to be one and then use voxel remesh which "bake" the object into one with no internal geometry.