Prep, then prep some more.
I waited until the structure was up and dried in, so the floor was cured almost exactly 6 months (poured 7/24/11, painted 1/20/12). I used a Kelly-Moore High Build epoxy KM-15. I had a "connection" and liked the product description. And the price.
Prep: I tried a "low voc" etch from HD - didn't really like it. I also used a 24" squeegee - much better than any broom for water management. Rinsed, squeegee, rinsed, again. Since I didn't see much reaction out of the special etch solution, I got some 31% Muratic acid (pool acid) and mixed that 8 parts water to 1 part acid. I crawled the floor with a grinder and flap wheel to knock off any loose material and "puffs". Then etched a second time, rinse, rinse, rinse. I did not use a pressure washer, I just used a nozzle with good pressure and squeegeed the floor after every rinse. I did not neutralize anything because I could tell the floor was taking care of that pretty quick. When etching, I kept it wet and went over areas several times. I worked hard to not let the floor dry with just etch solution on it. I used a 1/2" nap roller for the etch and kept the hose handy to wash it down as soon as the reaction seemed to stop. If I didn't like (some shine left) that area after rinse, I'd do it over. Let the floor dry using fans several days since it was in the colder months. I even used the wife's hair dryer to dry the few cracks. I moved the fans around to dry under the wall plates and any dead air spots.
Paint: I bought 3 units of KM-15, thats a gallon plus a quart of hardener per unit. I mixed the KM-15 per instructions and thinned it 10% with MEK. Hind sight says I could have done 15% and been just fine. I did two units in a 5 gallon bucket first, then did the last unit when the bucked was about 1/4 from empty. Total product came to about 4 gallons. Pot life was 3 hours and I did 960 sq/ft in 2 1/2 hours. I could tell it was starting to set by the way the roller was working towards the end. Used a 9" wide 1/2" nap roller. I did have to change a roller at about 2/3 time when the first started leaving nips on the floor. I cut it way close - The last 8 square feet at the man door was done by getting every drop out of the bucket. Hind sight #2 - should have bought 4 kits - I would not have had to "push" the last bit so hard.
Results: So far, so good after 6 months. There were a couple of low gloss spots where I got it a little thin but nothing major. These look like a once over with the roller, missing a second or third pass. These are not anywhere near the man door where I was sweating the finish, so go figure. Grip appears good, no pops or voids even in the rough floor areas. It's dirty in areas and has some scuff marks but I'd expect that from moving things around, dragging boards, OSB sheets, etc. I think -possibly- some of the area in front of the big door was a little slow to cure due to cold weather. It seems to have possibly picked up a very, very slight tint from wind blown dirt under the door seal. I can only just see it if I wash the floor real good there. Part of that is a little rough, so it may just be dirt in pores that can't get washed out. Since lots of dirt, mud, dog prints, gold cart, etc gets tracked through the big door (still no grass or gravel in front of the door) and in from the man door, it's never clean there anyway. There has been constant come and go out the man door where I scraped the bottom of the bucket and leaned on the roller like a shovel. There is no sign of wearing or thin coating.
Cost: Total was under $300. Coating, rollers, HD bucket, acid, etch, etc.
