I have three gallons of Sikken Log & Siding that are unopened, they are 8 or 9 years old. Sikkens says the shelf life is 5 years max. I opened one can to stain a piece of trim. Once it shaken and stirred enough it seemed go the wood just fine. I am ready for a maintenance coat should I stay away from this old stain or use it up? I have searched high and low for information on true shelf life without success. Thanks!!!