cinder block

Hi guys! I am a new member - I am an artist about to paint a mural on a cinder block wall. I have checked the existing topics and haven't found the similar problem. So I hope somebody could advise The specs are: The wall is brand new, in the brand new building. It's exterior. Made of CMU...

I'm new to the forum...just lurked a bit so far to get the lay of the land. Here's my problem... As part of a larger exterior job (our main business), our best commercial customer asked us to paint a small lunch room w/smooth cinder block walls. The existing coating is semi-gloss and I'd guess...