Seeking some advice before i go take the t-stat housing off again.

I had a leak from the plastic housing that was on the car. I replaced the housing with the aluminum one, and replaced the seals. After the replacement, the leak appeared from right about the same place.

(bottom of t-stat housing on the water inlet side, not the t-stat side)

Anyone had to use RTV or the like to get the aluminum housing to seal 100%?