TotalBoat Halcyon can be applied over linseed oil and tung oil but the oil material has to be completely dry first, polymerized into a hard film (this can take weeks or months, depending on the oil used and the conditions). If the oil is still tacky, Halcyon should never be applied to it. It is always better to wait extra time to make sure the oil has completely polymerized rather than to apply Halcyon and have adhesion or curing issues.