Abstract: A smooth, seamless arcuate-shaped inside corner is formed between a counter top and a splash board, both made from a filled polymer material. The counter top has a top surface, while the splash board has an end edge orthogonal to a front surface. The two articles are joined to form a butt joint therebetween, and a bead of a filled epoxy material is formed along the inside corner of the butt joint. A smoothing tool, which has a smoothing surface of the desired curvature, is used to smooth the bead. When cured, the bead matches the color and texture of the two articles and provides a smooth, seamless, arcuate-shaped inside corner. The filled epoxy comprises an epoxy resin and a hardener in a ratio of about 2:1 resin:hardener, together with a filler and/or a colorant. The filler comprises a mixture of alumina trihydrate and particulates in a ratio within the range of about 75:25 to 25:75 alumina trihydrate:particulates.