Running solo as a pale master, I find that I can deal adequately with most creature types. Constructs, however, are always a pain, especially the iron golem type of enemy, even moreso if it's red named and can't be insta-killed.
Some constructs, like robobeetles in Sharn, robodogs and warforged are vulnerable to negative damage; these are no problem, just blast as normal. Some constructs are immune to negative damage, but take normal damage from elemental attacks, like shield guardians, scarecrows or security drones. These are only mildly annoying, and readily fall to DBB, chain lightning, acid well and meteorswarm.
But those iron golems. Ugh. Immune to negative, healed by fire, and only yellow numbers from acid, cold and lightning. They take orange damage from disintigrate and cyclonic blast, but I can't seem to get a lot of DPS out of these. So I swap between cyclonic, disintegrate, and my various harder hitting cold and acid spells and it just takes forever to kill these yoyos.
So maybe there's something I'm missing. What's a good technique for dealing with iron golems?