Masking up well takes as long as the job itself. But it makes it so worth while when after your last spray you take the masking off, skip it and off home you go! What top coat do you use? I use BLI (Buxton Lime Industries) Limebond cement. It has cement, lime and air entrainer already added. Mix at 5:1 = 6:1:1. I use Sulphate resisting cement in the base coat if I can get hold of it. Cuts down on effloresence ruining the finsh. Rend-aid helps against salt but costs a bit and needs ti cure for at least 3 days. Putting SBR in the base coat helps too but again cost a bit but makes a stain free finish.