First of all--this is a first for me, and I am not much of a do-it-yourselfer. I am having some remodeling work done by a professional. After he finishes, I will be trying my hand at wallpappering. Before the professinal begins his construction work, however, I wanted to go ahead and do some of the preparation on my walls since it will be easier to do before he adds crown and chair rail molding. (I know, I could do that myself also--but I'm not.) I purchased a pole sander (the kind operated with elbow grease) and the service guy recommended 150 grit sand papper (looks more like sand webbing). I had read somewhere that "50 grit sand paper should be used to get below the paint to a surface that the paper will adhere to."
First question: which is stronger 50 grit or 150 grit, i.e., do the numbers go up for strength or down for strength?
Second question: The walls have the original coat of standard white slightly orange peel paint--the house is 15 years old. Do I have to take all the paint off or just smooth out the orange peel?
Third question: The little sanding I have already done seems to be going slowly. I could work myself silly trying to hand sand these walls (11 X 12 room) especially if I have to get all the paint off. I don't feel competent to do it any other way, i.e., using electrical machinery or anything like that. So do I need stronger sandpaper or what--I am using the 150 grit that the sales rep recommended and it is the kind that fits on to the end of a pole sander?