Effect of Copper Sulfate Impregnation on the Physical-Mechanical Properties of Sengon and Coconut Wood: Pengaruh Impregnasi Tembaga Sulfat terhadap Sifat Fisis-Mekanis Kayu Sengon dan Kelapa. perennial. 2026;22(2):93-100. doi:10.24259/perennial.v22i2.53690