Interesting to see how long a thread can get over sealing a thermostat housing and even more interesting on all the ways people go about the repair.
ie; don't do it if it's this temperature, only use this or that housing, this sealer, that sealer, etc., etc.....

The solution is really straight forward and simple
Clean flat surfaces, inspect for imperfections on sealing surfaces, thread sealant on bolts that are exposed to fluids, proper torque and a quality gasket. DONE