An old type primer surfacer you can spray in the cold just be aware that the drying time will be quite long but that doesn't seem to be an issue here. Having said that I also agree with Jerry and EtekRstos in the you want to warm it as much as you can to aid adhesion. Get the surface rough and clean first. If you're going to spray a catalyzed primer I would recommend contacting the manufacturer to get their guidelines for spraying at low temps.


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