Can Scaldera be defeated if you just keep bombing him untill all his crust..

Yes his eye is his weak point so that is what you have to damage by any means necessary. Removing the crust makes it easier to hit the eye

Alright, so basically Scaldera rolls after you. Run until you have enough space to throw a bomb at him, and he will roll all the way to the bottom, then suck in air, while he is sucking in, throw a bomb into his mouth and he'll be stunned, then slash his eye and run away from him because he'll start shooting out flaming boulders of his mouth, then he'll roll after you again. Just repeat the process. If you run out of bombs at the top of the hill/land thing (the place you are fighting Scaldera on) there are more bombs for you to stalk up on.

I only know the way where you bomb his mouth, much like King Dodongo, and attack his eye with your sword.