* Can remain tacky: Nail polish may never fully cure on polymer clay and can remain sticky. This is because the chemicals in nail polish can react with the polymer clay, preventing it from fully hardening.
* Discoloration: Over time, some nail polishes can yellow or discolor polymer clay, especially lighter colors.
* Brittleness: Nail polish isn't designed for the flexibility of polymer clay. It can crack or chip easily, especially on pieces that are bent or flexed.
* Compatibility Issues: Not all nail polish brands are created equal. Some may react worse with polymer clay than others.
* Uneven Finish: Achieving a smooth, even finish with nail polish can be difficult, especially on complex shapes. You might end up with brush strokes or pooling.
Better Alternatives for Glazing Polymer Clay:
Instead of nail polish, consider these more suitable options:
* Polymer Clay Glazes: These are specifically formulated to work with polymer clay and provide a durable, non-tacky, and often UV-resistant finish. Examples include Varathane, Liquid Sculpey, and Kato Polyclay Polish.
* Resin: Epoxy resin provides a very glossy, durable finish. It's a bit more involved to use (requiring mixing and proper ventilation), but the results are often worth it.
* Sand and Buff: Sanding with increasingly finer grits of sandpaper, followed by buffing with a soft cloth or polishing wheel, can create a beautiful sheen without any additional coating.
* Acrylic Varnish: Some artists use acrylic varnish (like Krylon Crystal Clear Acrylic Coating) with mixed results. Test first and apply in light coats.
If you absolutely want to try nail polish:
1. Test First: Apply a small amount of nail polish to a scrap piece of polymer clay and let it cure for several days (or even weeks). Check for tackiness, discoloration, and brittleness.
2. Choose the Right Polish: Opt for a clear nail polish that is acrylic-based (rather than nitrocellulose-based) and claims to be quick-drying and non-yellowing.
3. Apply Thin Coats: Multiple thin coats are better than one thick coat, which is more likely to cause problems.
4. Allow Ample Drying Time: Give each coat plenty of time to dry and cure completely before applying the next.
In conclusion, while using clear nail polish on polymer clay is possible, it's generally not recommended due to the high risk of problems. Exploring alternative glazing methods specifically designed for polymer clay will yield better and more reliable results.