I bought some GE Silicone II Sealant for windows from Home Depot. I used a little, and put the cap on. Apparently, the cap is not airtight, and something has evaporated out of the mixture. Now, when I try to use it, the stuff no longer hardens up. It just stays gooey. So I was wondering if there is something that I could mix into it that would cause it to harden up, like its supposed to. Any Ideas? I don't want to have to throw away an almost full bottle.
Thanks