I am purchasing an hobby farm that has on old dairy barn. The barn is in great condition, but is in need of repainting. I have never done this before, and am not sure of the process. There is some flaking paint that will have to be sc****d, but most of the old paint has just worn off. Does the whole barn need to be primed first? sanded?

My budget will not be huge, so I will be doing most of these projects myself and need the most cost effective ways for repairs...

Jessie