Hellow folks, I have restored many many farm tractors over the past twenty five yrs. plus and have used the tractor paint with hardner. I will only buy the tractor paint from the farm equipment dealers rather than the tractor supply source. The paint from the supply stores seems to be a little less quailty paint and tends to fade and turn color and fade over time. Also this paint may not always be a ture color match. In other words buy the Deere paint from the John Deere dealer and IHC paint form the IHC dealer an so on. It's more money but much better longer lasting quality paint. Adding paint hardner will imporve the gloss and hold its color for years to come. As always a good clean smooth suface with primer adds to the results desired. I also get and use the paint reducer where I buy the paint from. One additional .......... make sure you used a good respirator when spraying with paint hardner. The stuff is much like airplane hardner and hard on a persons lungs.