Creating Solid form Surfaces

Hey i was trying to model a hullform but when i removed all the naked edges the solid became transparent.
As you can see in the photos initially light pink was shining and looks solid surface but when i joined all surface in next photo it became red transparent.
I mean is it due to low rendering capability of my machine or is it something else?

Can you share your file, that will help to find out what is going on.

Tip: you can create screen shots with Shift+Win+S :slight_smile: