spitting problem

My 20 months old has been spitting for a month in my face or anyone's face around him when he gets mad or doesn't get his way or somehow even out of nowhere.  I've tried talking to him about it and giving him time-outs; No matter how calmly we tell him "no" he retaliates this way. It is extremely rude and very frustrating. He is a stubborn child who doesn't react to many forms of punishment. I have spanked, doesn't work and not the method I prefer. So what should I do now? Help!.

[Jessie12]

you could try taking away his favorite item.  I cant stand spitting and there would be no way I could handle it if they spit in my face.  Props to you for not taking the initial reaction and smacking him.  Maybe when he gets out of the "terrible twos" stage he will out grow it.  Best luck to you.