I have applied the first coat of render to a few retaining walls made out of brick. I used a ready mix mortar. Question is how can I get the second coat smooth. Also if its not smooth can the uneven spots be sanded down. If so what sort of sandpaper grade or sanding instrument should be used. I dont mind the uneven look but I am curious on how they get some rendered walls so smooth and fault free. Any help will be much appreciated. Thank you.