In tips it states "Sanding hi-build primer sends up huge billowing clouds of white dust, so it's best to do it outside on a windy day." Can I wet sand? It's 26 degrees out and our warm days are the high thirties so I can't go outside. How much odor from primer? I do have a power vent to outside which helps but not 100%. I am not worried about me I wear a mask, I'm thinking of my spouse :>). How does it compare to Varnish?