What your are describing is not what is commonly describe as a slice. That is you are not swinging - outside in with an open clubface. What you are describing is a pushed ball hit with an open club face. This can be caused by improper alignment. In your case, I think you foot line is too far right and your ball position is too far back. So, the club is on an inside to outside path relative to the target line and the club face is open because the ball is too far back in your stance and has not had a chance to close. If this is the case, simply square your foot line to the target line, and put the ball a bit more foward in your stance. To check your foot line, put a club at your heels, not your toes because when you flange out your toes, it can appear as if you are open. Hope this helps