Hi there I'm new on here an looking for info on how to use Weber how best to apply when to scratch up or how many ways you can finish it e.g. Sponge or plastic float scratch trowel ??? Weather you can treat it like sand cement render?.basically the customer wants it flat as possible an all I've seen on YouTube or Google is about scratching it up ??? Can you make it flat if so how??? I'm an indoor man mostly over my year's although I can cement render an float an sponge an have over 16 years experience or more so im no novice it's just a new product to me any help would be great .