I just mix up the bag to a soupy consistancy and then paint it on until it is all gone. Yes, your flares will discolor. They should back in the casting about a 1/4". I pack Inswool around the burner tube to keep the drafting of heat back up along the burner. It is also a good idea to plug the end of the burner (air inlet) when the forge is turned off to keep the heat from drafting back inside the burner tube. I leave the plug in place when lighting the forge. You will get a soft fluffing flame when it ignites,,,, then stand back and pull the plugs out.