"Cliff Hartle" wrote in message
...
Screws in the end grain of a 4x4 post don't have much holding power. It
wouldn't take much of a push at the top of the box to pull out the screws.

You could screw a 12" length of maybe 1/2" threaded rod into the end of
the
post and use a nut and a very large thick washer inside the box. The mesh
bottom shown in the lower picture may weaken the bottom and may make it
hard
to mount it this way.

You could put it on top of the post but attach a piece of 1x4 to the back
of
the post and mailbox.
I think this would give you the slim look you are looking for.

What he said. If you go with bottom mounting, make sure to bottom is strong
enough, and attached to the solid parts of the box well enough, that a
strong wind or obnoxious kid can't simply repeatedly flex or wack the box
hard enough to tear the base out of the box. If you want a strong but classy
looking mount, I'd find or fabricate an 'L' bracket to bolt the back of the
box to, with short leg of the L attached to the top of a boxed surround that
fits over the post, to keep the end grain dry. Farm supply stores usually
have a whole aisle of miscellaneous ironmongery for building or repair of
stock pens and barn doors, and may have something you can easily adapt. If
not, your local machine/blacksmith shop could probably knock it out pretty
cheaply.

aem sends....