I’ve got a 3′ X 20′ long exposed exterior foundation wall made of concrete block (in upstate NY).  I have re-parged most of it, but since I applied N -type concrete to existing block where 85% of the original parge had fallen off, I now have new vs old parging, hence a somwhat uneven surface despite my great attempts to level it as best I could.  

Any ideas for resurfacing the whole thing with a sand/cement wash that is brushed on?  I have already painted it with an acrylic elastomeric coating, i.e. fancy latex paint….hoping it would cover up the imperfections.  All it’s done is highlight the various surfaces and the lack of a flat plane surface.  

I could add pics if that would help.

Thanks.