I have a 1990 28ft Hunter, recently I got a moldable packing from marine store to make dripless shaft seal, should be installed in combination with regular packing, on my model there is a plastic stuffing box. On empty stuffing box - one layer of regular, one layer of moldable and again one layer of regular packing. When I removed the nut and checked the box was empty (i recently got this boat from RCR Yachts, was not in water). I was able to fit only one layer of 5/16" packing is this normal?