The HD PT lumber is crap. We buy our lumber from a dock supply company and it is better but still treated with the same cheap chemical. It used to be creosote treaded like telephone poles and railroad ties, it'd last a lifetime. Pretty much every place that did that treatment in the past is now a superfund site. It's some coal tar derivative which is something that we still use in industrial painting, it is nasty but you can not beat the weathering durability. Eventually it will be banned all together like chromate.
As far as signs, paint it. Sorry Tex, luv ya, but raw wood looks cheap. And pull the tags off..... and the backing off the ACM for Christ's sake. I dunno about you Texans.
My summer job as a kid was to paint sign posts (and clean screens, empty garbage, scrape paint off the floor) used a little 4" roller and god knows what kind of paint. They were all painted, including real estate signs. Then we would touch up any marks that we made with the tamping bar after we put them in. Remember, your reputation is based on your work, not how much money you make. Don't skip steps because someone is cheap, either up the price, eat it or decline the job.
