I don't tank it, I dps it, but I know our tanks say they take 18k hits from it. What we do is have the tanks ping pong the boss constantly. They save their cooldowns until the second phase of fighting just him. They only tank him when cooldowns are up. The tanks try to stay at max distance from each other while staying in taunt range. They taunt, then run, if he charges them instantly they pop a cooldown, with the other tank taunting asap. One of the tanks usually dies here. We rez them asap and keep going. We tend to lose at least one other when he drops agro during this or we lose a tank again, but it's an all out burn phase. We've been able to gun him down each time. Actually trying to stand and tank him is a bad idea.
I've read similar strategies to this and like the idea, however we have another somewhat unique problem in the fact that we are typically running with 4 melee dps...and sometimes 4 bad marauders. We can move around some, but bouncing the boss back and forth between 30 meters will be a huge dps drain. Any good ideas around this?