Ok, so it's probably not impossible, but I've spent a week on it and there has to be an easier way to model this. At issue is the area where the tank bottom piece meets the tank's side walls (the front end of the unit -see pics). Two flanges having different angles meet and then transition into a steeper angle before bending into a "lip". I'm constrained by the actual dimension of the physical tank that I'm modelling. I basically ended up brutishly hacking at it until the over all dimensions of the assembly were what they needed to be. I could really use some help.