What is the best stain for Therma-Tru fiberglass doors?

The best stain for Therma-Tru fiberglass doors is Therma-Tru's own Same-Day Stain kit and stains, which are specifically formulated for Therma-Tru fiberglass doors to ensure proper adhesion, color, and warranty coverage. Therma-Tru offers its own line of stains including English Walnut, Mahogany, Oak, and other colors that are designed to work with Therma-Tru Classic-Craft and Fiber-Classic doors with wood grain texture. These stains are acrylic-based and allow staining in one day without long drying between coats, and are recommended to maintain warranty. For best results, Therma-Tru recommends using Therma-Tru stain with Therma-Tru topcoat for UV protection. Other high-quality stains that work well include Minwax Gel Stain and Old Masters Gel Stain, which are oil-based gel stains that adhere well to fiberglass and provide rich color, but using non-Therma-Tru stain may affect warranty if not applied per instructions. Preparation is key, door should be clean, dry, and primed if required, and stain should be applied in thin coats with brush or rag following wood grain, then topcoated with spar urethane or Therma-Tru topcoat for protection. For Smooth-Star smooth fiberglass doors that are meant to be painted, stain is not recommended, paint is better. For Classic-Craft with deep wood grain, gel stain provides best wood look.