when spraying on this product, how much of an smell does the paint give off. I have a large picture window, how long do I need to keep the window open

Thanks for reaching out! Rust-Oleum Automotive High Heat Primer is a solvent based primer designed for use on on automotive engines and other automotive surfaces which reach intermittent temperatures up to 2000°F. This coating requires heat curing, raising the temperature to 250°F for 30 minutes, then allow 30 minutes to cool. Next heat to 400°F for 30 minutes, again allow to cool for 30 minutes. Finally heat to 600°F for 30 minutes, then allow to cool for 30 minutes. This, and all spray paints, should be applied outdoors or in a well ventilated area like an open garage. Do not apply indoors. - Rust-Oleum Product Support 6