Idioms concerning solid/hollow objects

[neoteric]

I wonder whether anybody knows the following idioms: 1) idioms relating to solid (possible long) objects (including weapons) that indicate a person with positive traits or describe a person in a appreciative fashion. (e.g. he is a pillar of society) 2) idioms relating to hollow, container-like objects that indicate negative traits in a person or describe a person in a derogatory fashion. (e.g. bottle-head) ...possibly widely known (not regional) expressions.

[xyzzyplugh]

neoteric, 'you're a brick'. [positive solid]. My girl, 'she's a dish'.[positive hollow]; The guy next door is 'a mere shell' of the man he used to be,[negative, hollow], You're 'the apple of my eye' [solid positive]. You're a 'son of a gun' [weapon, positive] Is this what you meant?

[incitatus]

1) a rock (dependable person), straight as a rod(or arrow) (long, weaponlike thing), a tower of strength (ok, towers are often hollow, but it has a solid feel) 2) hollow as a gourd, empty as a beggars bowl.....this is all very freudian isnt it? IS it an essay? phallic/positive, yoni/negative?

[RCP]

Head like a sieve. Running on empty.

[Gef]

"As thick as two short planks." Solid, negative?

[gazzawazza]

Would "Empty vessels make most noise" count? Negative, hollow, container-like...

[xyzzyplugh]

This is the weirdest Q. I have seen on AB, have a star neoteric.
The pinnacle of one's career (phallic, positive), 'The dish ran away with the spoon' (sounds quite sexual after this little foray).