If you feel just about anything then split up the clumps and see When the mass mixes back in with the general regularity with the stain. If it dissolves in to the stain you can use it. If it remains lumpy the stain has separated and it is no good. http://socialmediainuk.com/story7369090/the-best-side-of-how-to-clean-barbacue-stains-from-a-trex-deck