Thermostat no good or Leak Sealer ???
 

Hi guys I hope someone can give me some ideas here, I just installed a new thermostat and cooling tank on my 06 MPV, everything was working ok, till my radiator started leaking, I followed the instructions of how to drain the radiator to flush old antifreeze did that plus I used a leak sealer, was driving for about 45 mins when i noticed smoke coming out from under the hood, opened up cooling tank was empty, pulled over waited until the engine cool off and add it more antifreeze, it happened again later down the road, is like the thermostat is not doing its job, right now I'm thinking this leak sealers had something to do with this? any ideas of what else should i take a look?

thanks in advance guys I hope someone can help me on this :(