Review on 🏞️ Revolutionary Polymaker PolySmooth Sandstone Filament: Achieve Layer-Free 3D Prints by Erik Snyder

Excellent yarn. I purchased this product specifically for AlNiBr sealed investment cast (ceramic case) impeller housings. It prints well, but slowly, with minimal warping. Smooth inner surfaces are vital to them, so the ability to smooth prints makes this filament the only real choice. The smoothing process prevents the shell from penetrating the casting, which is undetectable and degrades the casting. We also sealed tight tolerance areas with some petroleum jelly. It burns very well with minimal ash and no shell cracking. In fact, during testing we were able to use hot air to quickly dry the layers without cracking the shell. Overall, Polysmooth is a significant improvement over wax in almost every area. Mechanical strength is greater, the mass is a small fraction of wax, and when it burns out, it smells like marshmallows.