Hearing that I was planning to put up a fence, a friend who owns a small
farm (but does not work it herself) offered to lend me a post-hole digger.
She called to say that the guy who works for her is even willing to come
dig the holes and set the posts for me, but his standard method is:
for 4" posts, use a 3" post-hole digger, then drive the posts in and
throw the dirt back in. No concrete necessary.
Please tell me that, while this may work for chain-link or barbed-wire
fencing out on the farm, this isn't going to work for posts to support
fence panels in a residential environment. I see two problems: (a) how
do you ensure that the posts are plumb? (b) the tops of the posts are
going to get wrecked in the course of driving them in.