Along the banks of the Rio Grande in Presidio, Texas, stands Historic Fort Leaton State Historic
Site. It is constructed of native materials of earth, rock and wood.
In this video, masters of adobe plastering at Fort Leaton demonstrate how interior walls
and floors are repaired and maintained. They conform to the same principles and techniques
that have been used over the centuries to preserve this site: One of the largest and
finest historic adobe structures in Texas. Adobe plastering is a multi-stage process
that is completed over a period of days and weeks to allow for proper drying, cracking,
filling, white washing, and curing. Exterior walls are finished with an adobe
mud plaster. Interior walls are protected by a heavy coat of white wash. Most of the
same materials used in manufacturing adobe bricks goes into making adobe plaster. Screened
clay and sand is mixed with a blend of water and Aerospray 70, a binding agent. The first
and second coats of plaster include a small amount of straw. Sammy Marquez from Texas
State Parks and Wildlife explains. Here is the first coat. You can see the stones,
and you can see the straw that we use. The straw helps it bind, mixed in with the Aerospray 70
that we put there. When it dries, it bonds pretty good.
This is the second coat. As you can see, there are no stones. It is less rough, and it will
help you do the finish work for the third coat.
This is what we're going to use for the final coat. This is what you want to see runny.
It's the same process as the second coat, but it's just more Aerospray 70 mixed in
with water. We're doing some plaster inside the structure.
It's the first coat, so you want it to be a little rough. As you can see, it has straw
with stones mixed in. Here we're getting ready to use the wooden
trowel. He's going to soak it, you want to have it soaked. You just do rounds. You
want to overlap what you plaster. That way you can blend in the old plaster with the
new plaster. The runny mixture we'll use for the third
coat is applied with a brush. This final coat will dry without cracks.
This is the way we do the white wash. As you can see, we still need some more.
But after it dries up, it's going to get the white color.
The white wash is lime, salt, and water. What we do we leave it to soak it for two weeks,
and it should fill all the little cracks. Here we have a patch that covered a crack.
We used the same plaster that we used on the third coat.
Now we completely sealed the floor here, you can't see the patch no more. We also sealed
it with Thompson linseed oil sealer. Here we already did the three coats: The first,
second and third coat. It's now ready for the white wash. We do this section first and
then we come do the complete wall. As you can, we completed the white wash. You
can hardly see the patch that was here. We went on and finished the complete room.