I am working on an old horse trailer. It will be difficult to get the trailer into a garage so I will most likely be painting outside. I will be using Eastwood Chop Top Silver Metallic and Eastwood Midnight Black Metallic single stage urethane paints over EW 2K Urethane Primer Gray. As i will be working outside, I am concerned with the ambient and surface temperatures. What temperature range is acceptable? Are there any other additives needed if lower than desired ambient temperatures are unavoidable?