so they point in not out
“W” then “0”
what you want is “flip normals” in edit buttons. w->0 as mentioned is a shortcut for this.
random other normal stuff:
ctrl-N is “recalc normals” which will attempt to orient all normals outwards.
ctrl-N may fail on certain non-closed meshes or non-manifold meshes.
These require finding the problem by hand usually.
one aid for non-manifold meshes is space->select->non-manifold, which will try to selected vertices and faces that don’t make sense.
turning on draw normals in edit buttons can also help in tracking down normal problems.
thank you both