Just doing my first burn on a PH. Trying to cure the paint. Rear exit flue into fireplace so thermometer is on the top plate. The paint brochure says to do 400 degrees for 45 min and then 600 degrees for 60 minutes or so. I am a bit confused on how hot I need to have the thermometer read? Is it at these numbers or is it at 1/2 half these numbers because the firebox is considered twice as hot as the top of the stove reading?