sbr problem

[masterplaster]

Hi i am rendering the rear of my property i have used sbr slurry mix [two parts opc one part sbr] to prep the wall, unfortunatly the slurry went off before i could put the scratch on.

If i apply the scratch to the dry slurry will it blow? or should i put a new coat of slurry on top of the old and carry on?

Any help would be greatly apprecaited

 

[Micilin]

Is the slurry rough in texture -ie will it provide a good physical key (pic maybe)

If in doubt, just slrry again and apply render when tacky