Walls and Ceilings - topping on drywall

I've just finished taping the seams on my new drywall, and I've done 3 coats of mud with sanding in between. It's nice and smooth and now I've been told that I should add topping before I paint to smooth out any imperfections. I think I need a 12" trowel and a special mixture of mud. But how much water should I add and are there any special instructions for applications or differences between topping and regular mudding?

thanks so much,
m

Topping is drywall mud that is very soft and easy to sand. If you were to use topping you would have used it on your 3rd coat. I think you might be done. A top coat is a really light coat that fills in any scratches or dents. If you feel like your job is ready you can put one coat of paint over it then you will see what will show and touch up then.

Thanks! Can I just add some water to the mud I have left, and if so, about what consistency should it be? Also, if I did paint it with one coat to get an idea, can I put topping over that coat of paint if I see problems?

thanks,
m

yes you can use the mud you have left. You can thin it out with water or not. It's up to you. If you think you need another coat go for it before you paint. You can put mud over paint but then you have to paint again. A lilttle waistful.