The only foolproof method I know is to get the tiny cans and use it up when opened. I use the 2" Harbor Freight disposable brushes and nitrile gloves and toss all of it when done. Russell Criswell Vulcan's Forge 3936 Broadway Kansas City, MO 64111 816-931-6303 816-931-9378 fax 877-531-1046 toll-free www.vulcans-forge.com