This famous "hot brown" formula quickly produces rich authentic chocolate brown finish on steel. We use it in our shop, for touch-up, repairs, and small parts. Large surfaces (barrels) require thorough cleaning to achieve an even finish. Scrub with detergent and hot water, then use degreaser. Warm the part until the solution sizzles. Swab on the solution until evenly browned. Several coats give best results. Allow the part to age several hours before oiling, giving the oxide time to bond to the surface. After-rust, darkening the finish, is normal. Poison! Avoid contact. Sold in 5 oz. bottles only.