I have a bunch of older G&H water keel duck decoys in standard and magnum size. In the 1990's I bought the water keels because of packing rigs a long distance on foot and less weight made sense. Fast forward to 2018 and I still have an odd couple of dozen of the old G&H water keels that are still in pretty good shape and I plan to continue hunting with them. The premium now is not light weight for hiking decoys in a long distance. The premium is a decoy that will self right when you toss them out. On the old G&H decoys that I have the keel is sealed off in the front and only open on the back which should make filling with sand and sealing off the open back an easy process. Questions: 1) Anyone have any experience with adding sand to the water keel and sealing off the open end with silicone? Will the sand added to the water keel of a G&H decoy add enough weight to make the decoy self right? 2) Is there something better than silicone to seal off the opening? Thank you in advance for the replies!