I've bought oak sills and returns for my new windows, they've been in upstairs room whilst i've been knocking the plaster off in downstairs and in the bathroom, they have got a coating of dust on them (depsite covered in plastic).
Whats the best way to clean them off ready for varnish? dust them over with a brush then wipe with white spirit in a rag?
i'd actually run the hoover over it to get as much of the dust off as possible. i always vac woodwork prior to painting. then, as you say, wipe with white spirit and a cloth (lint free) allow to thoroughly dry then varnish or apply whatever finish. test a small area first in case of discolouring but should be fine. check compatibility of the product you are using - oak doesn't awlays hold a varnish too well. personally if it were oak i wouldn't seal it at all. it's a very resilient wood and in my opinion one of the most attractive and is just as good, if not better, left without an applied finish.
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