Hi i'm a new plasterer and have recently done only my second job which was a large ceiling. The ceiling had been boarded and just needed skimming. As i'm new to the game im not sure of the best technique, as i was plastering the ceiling the plaster was drying out far to quickly and was becoming unworkable. This resulted in obvious joins in the plasters. Is there any way to reduce the time the plaster goes off? Also please can someone give me some tips on how to do a large ceiling area? Thanks.