In this video, Kirk Giordano of Kirk Giordano Plastering demonstrates how to patch stucco, how to patch stucco around multiple wall penetrations, and how to add a faux block and mortar face to the stucco patch. As usual, Kirk spins a yarn while patching stucco to the parts of the workspace he is not going to talk about. He finds himself talking about Cannery Row by John Steinbeck.
How to patch stucco: the scratch coat
Using a long trowel, he applies mortar along the edges of the area to be patched, pushing in and up along the top and bottom and pushing the mortar in and over along the sides. He holds the hawk under the trowel, tight to the wall, to catch any droppings. After the first row of mortar along the top, he applies another from the top of the pipes into the previous course.
He began his tale to Steinbeck by remarking that the homeowner bought a short trowel to fit between the pipes sticking through their wall. This prompted him to deepen his voice and say, "Man, how bout this: you just lath it, and we'll come and do the stucco?" so he could demonstrate how to use a long trowel between tight pipes.
As he works toward the pipes, he changes the topic from Steinbeck back to stucco because he has worked down from the top and up from the bottom enough to demonstrate how to apply mortar between the pipes sticking through the wall.
Push the trowel vertically into the lath right next to a pipe and diagonally upward toward the next pipe. Next, do the same thing but in the opposite direction from the next pipe, thus mostly filling the space between the two pipes.
The brown coat is the second coat
After the brown coat has dried enough, apply the scratch coat—the second of three coats. The brown coat brings the whole patch to the same depth as the rest of the wall.
He uses the same technique of pushing the stucco in and up. If you pull down, you'll pull the mud off, "we don't want to pull the mud off when we're putting it on."
Kirk uses an accelerator in the stucco mixture to speed the curing process so he can do all three coar=ts in a day instead of coming back day after day. He will let the second coat cure for about 15 minutes before coming back to draw the mortar and block lines.
Scratch block and mortar lines in stucco
Step one is to use a level to lightly scratch lines as a guide for working the mortar. He uses a concrete seam tool to "draw" lines along the guidelines. Keep the edger wet, or it will drag stucco along with it. After seaming all of the lines, he turns to widening the lines to match the existing pattern. You can use a brush, like a paintbrush, or a sponge float to widen the mortar lines. With the float, you'll need to pull the edges into the center of the 'block to clean up the pattern.
To smooth the new work into the old, use a sponge float to feather the wet stucco lightly into the existing work.