Does rust damage the

Myths about rust on plaster mesh

Our welded plaster mesh is packed in polyethylene so that it does not rust on the ship on the way from China. Once there was an emergency and we received a slightly pink welded plaster mesh.
Experienced plasterers said that such a "walking" mesh is better suited for plastering work, and here's why:

• Lubricant residues on the freshly welded mesh prevent the plaster from sticking to the metal.
• A light layer of oxides on the mesh helps create an intermediate adhesive layer between the metal and the solution.

We are a specialized company for the sale of metal meshes . We supply welded mesh throughout Ukraine. Buyers listen to the opinion of our experts. Therefore, we decided to confirm the opinion of practitioners-plasterers with two experiments.

EXPERIMENT #1

The purpose of the experiment: will rust show through a layer of plaster of different thicknesses if a rusty mesh is used as a plaster mesh.
Bricks were plastered using rusty plaster mesh. One brick was watered, the other was not.

Diary of the experiment (all photos are enlarged)

September 29, 2011.

We create two samples. We take two silicate bricks and cover it with a layer of cement-sand plaster about 5 mm. We impose a rusty grid on a layer of plaster.

Sample #1 Sample #2

We cover the mesh with three layers of plaster: at the beginning 5 mm, in the middle 10 mm, at the end 20 mm.

Sample #1 Sample #2

Leave part of the grid unplastered. We designate the samples with the numbers 1 and 2 on the bricks.

October 6, 2011
The plaster layer on both samples hardened.

Sample #1 Sample #2

While on the plaster we do not observe any traces of rust and stains. We point a clearer number on sample 1 and pour it with water.

We leave the second sample without watering.

October 13, 2011.
Pour sample number 1 with water

On this sample, part of the plaster at its thinnest point, where the thickness was about 2 mm, fell off, exposing the welded mesh. But no stains were found on the surface of the plaster.

October 20, 2011.
Sample No. 1 before watering, during watering and after watering.

There are no rust spots on the surface of the plaster.

October 27, 2011.
Sample No. 1 before watering, during watering and after watering.

A month later, with watering once a week, rust spots were not found even on the thinnest layer of plaster.

Conclusion: the use of rusty plaster mesh does not lead to rust seepage onto the plastered surface.

EXPERIMENT #2

The purpose of the experiment: to find out whether the layer of rust on the plaster mesh affects the adhesion strength of the plaster to the mesh.
To do this, we made two samples with plastered bricks. On one sample, a rusty mesh was used, on the other, no traces of rust were used. The thickness of the plaster layer is 1 cm.
Our task: to determine how easy or difficult it is to chip the plaster from the metal; pay attention to the mesh itself, whether the mesh will rust under the plaster, and what color the plaster will be where it came into contact with the metal.

1. All stages of the experiment with a plaster layer containing a rusty mesh.

September 29, 2011 - creation of an experimental sample (all photos are enlarged)

November 3, 2011 - we break the plaster, look at the grid and at the plaster (all photos are enlarged)

Rusty grid more than it was, not rusted. No traces of rust were found on the plaster either. The strength of adhesion to the plaster is high, all the wire after the destruction of the plaster layer is covered with traces of plaster.

You can see in the photo that the mesh, freed from plaster, has a whitish color due to the mixture of sand and cement adhering to it.

2. All stages of the experiment with a plaster layer containing a non-rusty mesh.

September 29, 2011 - creation of an experimental sample (all photos are enlarged)

November 3, 2011 - we break the plaster, look at the grid and at the plaster (all photos are enlarged)

For a month, in the plaster layer, the welded mesh did not rust and remained the same as when creating the experimental sample. The adhesion strength is small, the surface of the wire after the destruction of the plaster is clean.