the best way i,ve found,is to put a cone shape in the hole first,(in order not to get any resin on the thread) cause it,s a bit of a bugger trying to screw the top on with grit in the thread. Fill resin 3/4 of way up, and then pour pure water in to cover the resin, after that bung the top on,,,job done,,if you try putting the top on without putting the water in first you,ll find it difficult to get the thread to turn because it never seems to drop straight down through the resin ,,hope that helps