Be aware that many interactive items and hints in the game are red herrings. Incorrect solutions like alcohol, lemon juice, hot water, oil, a knife, and sunlight will not work, even if the game provides hints that they might dissolve or melt glue. The sunlight attempt specifically fails due to cloudy weather.
Focus on finding a heat source to melt the glue. The hairdryer is the key item. Don't get sidetracked by other items that seem plausible but are intended to mislead.