I am sure that this should be asked in a separate forum/thread, but I will strike while the iron is hot. I am new to repairing stuff except that which generally easily unscrews without resorting to extreme methods. I would like to get this frame done quickly if possible and at least expense since I have acquired the proper tools and don't want to bring to a bike shop for this work unless absolutely necessary.

I assume that the BB was unable to be easily removed so I am going to first pretreat with PB blaster penetrant and then wrap in plastic and submerge in ice cold water until thoroughly chilled. I will remove it from the water and immediately warm it up with a heat gun (think higher temperature hair dryer; I use it normally for industrial heat shrink sleeving). I do not want to torch it as it looks like it has undergone that already (would that extreme localized heat cause improper tempering or weakening of frame connections?). I am thinking that going from rapid extremes of temperature will, due to expansion and contraction, help break the corrosive 'weld' between the cups and shell. Does this make sense, or am I nuts?