I have just had a room replastered and need all the skirting boards cleaned and sanded ready for reglossing. However there is plaster all over the skirting boards and so question is is it better to clean off the plaster first and then sand or to do it all at once? Also is a sander with a bag on worth it and can they be used on a mitred skirting board or should I stick to good old sandpaper and elbow grease?
Answer:
Knock off the bits of dry plaster, othewise you will be spreading a lot of plaster dust with the sanding. A dull knife or plastic spatula would do the job.
A sander with a bag is a great idea, if you value your lungs. It will come in handy for other things later. The lower price “handyman” model would do your job fine, you don’t need a “professional” model as you won’t be using it 8 hours a day. There is a shaped sander available, shaped like the bottom of an iron. The point of this can get into grooving in the skirtings. For very tiny grooves you would have to use hand-sanding paper, folded to be using the edge. They don’t need to be totally stripped back to bare wood.
Source: YAhoo answers