Jim, I do not know what kind of silicone sealer you are talking about using but I do know that most things will not stick to silicone and I am guessing monocote is one of them. I would use a different kind of sealer and stay away from the silicone if you ever want to put anything over the top of it again. I know that painters hate armorall because it has silicone in it and they can never seem to get it off before painting and paint won't stick to it. I have heard of using water based poly to seal the wood and then covering with monocote. I have done this with mixed results. I don't think I let the sealer dry enough and had problems with it bubbling under the monocote when I applied heat to it.