Ok, so to dam, or not to dam on buttercream filled cakes? I keep getting unsightly bulges despite every effort to stop them! I let the cakes cool completely, settle overnight filled...and still, I got a bulge! I can't afford Sugarshack's DVDs right now, so I am trying to learn on my own! Please, someone help me! I have searched, but maybe I am not typing in the right key words, but I don't seem to get very good search results...
I find refrigeration helps a ton....it allows the buttercream dam to firm up and stay in place, and then after the cake is iced it really stays firm for you.
I've recently started using the ceramic tile methos to stop the bulge and so far have had pretty good luck! I think it was Leah_s who recommended it. Once the cake is filled, warp in saran wrap and place a ceramic tile on top for 3-4 hour (more if you have the time). It helps the cake settle and stops the bulge!
This article/tutorial has some great tips on how to make sure the cake is leveled well before even putting the filling in, to avoid bulging. best article on the topic that I've seen.
(you have to copy and paste it in your browser because the word "cake boss" hilights and disrupts the clickability of the link.)