If you've ever spent time as a mason's tender, you'll swear at times that there are only two words the mason knows: "More mud!" Mud is the mason's word for mortar. And even if you manage to keep mixing it fast enough, it seems the mud is always too wet, too dry, or just too bad! Constant attention is essential to the mason's work. Different jobs require different mortars. The work will go more smoothly, and the results will be more professional, if the right mortar is matched to the job. What is Mortar? Mortar is the "glue" that holds masonry units together. It has four basic components: portland cement (type 1), hydrated lime, masons' sand, and water. All four ingredients