No matter what I do I my cakes bulge. I've torted with thick buttercream, I've chilled before fondant, I've chilled after fondant, I've even put 2 layers of fondant on a tier and it still bulged. What am I doing wrong? Any suggestions?

Do you trim up the sides of the cake before icing them to make sure they are perfectly straight? If you do, it almost sounds like your cake is a lighter texture and is collapsing on itself with the weight of the icing.

once i have filled my cakes and before crumb coating i put weight on top of them - normally wrapped fondant (twice as much as I will be using to cover the cake). I leave it for a few hrs and this seems to just let any filling bulge so it can be smoothed again before covering with fondant. since i've been doing this i've not had bulges.

http://cakecentral.com/cake-decorating-ftopict-633571-newest.html+trick

Have you seen the above topic.

Thank you all for the suggestions. and thank you Texas Sugar for the link. It was great help. I will definitely use the tile method next time.

Since summer and heat are here. I'm trying something different. I'm making my dam out of cake ball stuff (the cake/frosting mix) I either pipe it around the cake with just a coupler on the bag or just shape it into a log. So far good results.

Does it only happen to cakes covered in fondant? If so, try using ganache instead of buttercream. There is a thread floating around that has several youtube video links about how to make chocolate and white chocolate ganache and cover a cake with fondant using this form of icing.

I only use white chocolate ganache under fondant (doesn't change the flavors any more than using buttercream). Works great in my opinion.

This is what I consider the best article on anti-bulging. http://www.cakeboss.com/PreventBulging.aspx

(You will have to cut-n-paste the link since CC hilites the 'cake boss' part)

How the cake is leveled seems to be the key in having a nice looking no-bulge cake. I know that once I found this article, I saw a definite improvement in my own cakes.

I do the exact same thing that Indy does. Pipe a thick rope of frosting where the each layer or seam meets. I use a small offset spatula to smooth the excess frosting into and around the "seams", wait a bit for the BC to set up, then crumb coat the entire cake.
I was given this hint by a fellow caker quite a few years ago, and can honestly say, my bulging problems disapeared shortly after.

also the denseness and sturdiness of the cake may be an issue. If the cake is too soft, it will compress upon itself causing a bulge, despite you doing everything "right."