I hadn't had a cake bulge in a long time (one over the holidays, which I threw together in two seconds and did all in white, so it showed quite a bit ... but none since). Well, I did it again! Simple two-tier, but I made the filling quite stiff because I wanted it to be a nice almost nougat-y consistency when cut into. The top layer to the cake was a bit softer than it should have been, and when I torted the very top-most portion, the stupid thing gave out more than expected, and with that thick layer of filling, is all bulgy now. ARGH!!!!! I HATE THIS!!!! I came downstairs this morning and found it all rounded off, all icky. No way to fix it except to cover it up now, though I didn't originally have anything planned to go over that part. My husband keeps saying that none of my friends will know the difference (it's for a friend's baby shower), since they're not cake people at all, but I don't give a rat's patootie. When I'm just trying to master a technique, I expect to make plenty of mistakes, but I absolutely hate messing up on something that should NOT be a mistake.
Anyhow! Thanks for letting me vent Back to the drawing board.
I had this happen recently. I came downstairs one morning to find light pink cake with a bulging middle.
I scraped away the bulge and added another, thin coat of BC (I use a crusting BC). It worked just fine and the cake was one of my smoothest ever.
I always place a dam around then fill, crumb coat and let settle before icing. Helped my bulge!