I made a few fondant figure people yesterday but when I went today to finish (add the head), the arms and other parts started to fall out. What can I do to make them adhere again since water isn't working this time???
Use some tylose mixed with water, or meringue powder mixed with water, or a small piece of fondant dissolved in water. Plain water isn't strong enough to glue together pieces that have dried, or to keep heavy pieces stuck on. The tylose works the best in my opinion but if you don't have it on hand, then the others will work too.
Royal Icing works well too. but its not INSTANT. so you will need to put something under each body part to hold in place while it dries.