How many hours can we keep thinned paint? by kamalakkannan | Jul 10, 2018 | 0 comments You can keep a thinned paint for 24 hours. Take care to use the thinned paint within the specified time. Submit a Comment Cancel replyYour email address will not be published. Required fields are marked *Comment Name * Email * Website Save my name, email, and website in this browser for the next time I comment.