Do you separate an imperative after a conjunction by a comma?

Question

I want you to go and ask him the price, but don't tell him I sent you. Is this a main clause followed by a coordinating clause (imperative)? "Pour the vodka into the glass, and add orange juice." Here, should the two following imperatives be separated by a comma?

Answer 1

This is tricky. The first sentence definitely needs a comma, because, "I want you to go and ask him the price," and, "Don't tell him I sent you," could be separate sentences without the conjunction "but." In the same vein, I'm thinking the second example should also have a comma, because, "Add orange juice," is an imperative sentence in its own right.