Do you know, that… ?

There is a relatively quick method of converting a surface into a solid and vice versa.

Let's start by converting a solid to a surface.

There are two ways to do this quickly. All walls must be selected (e.g. Ctrl+A) and choose Offset Surface by zero or operation Knit surface.

Basically ready with one caveat. This creates a new surface feature, while preserving the solid object. However, you can always delete the solid as Delete object.

However, in order to obtain a surface from a solid in one operation, remove any face. Preferably flat. But later, the resulting hole would have to be plugged and the surfaces rejoined without creating a solid. This results in two additional operations, so ultimately the first method will be better.

In turn, the conversion of a surface into a solid will be possible using the operation Thicken. If the surface is open, We are using Thicken, if the surface encloses the volume inside – we also use Thicken with option Create a solid from a closed volume.