I support adults with learning dissabilities in a workshop,and we are making concrete garden ornaments but we cant stop getting air bubbles in them,we do use a vibrating table,any suggestions please.
Tut may be right. Your mix may be too thick (dry) and the bubbles don't have time to migrate to the top and escape. I've seen this happen with plaster of paris.
Try a looser (add more water) mix and see what happens. Don't forget to vibrate.
