April 04, 2023

Two Cloth Cleaning Method

We have talked in previous blog posts about the importance of substrate surface preparation before the application of a sealant. One of the steps in the installation process is the cleaning of porous and non-porous substrates. Today we will discuss the cleaning of non-porous substrates such as metal, glass, and plastic.

Non-porous substrates can be cleaned more easily than porous and require less invasive methods. The most effective method for cleaning non-porous surfaces is by solvent wipe. Compatibility of the solvent used with the surface to be cleaned must first be established. Confirm compatibility with the substrate manufacturer before starting the cleaning process. Once compatibility is confirmed Pecora recommends the “Two-Cloth” method.

The “Two-Cloth” method is carried out as follows:

  1. Pour an appropriate amount of an approved solvent onto a clean cloth. Do not dip the cloth into the solvent container, for this can cause contamination of the clean solvent.
  2. Wipe the surface to be cleaned with the solvent cloth using sufficient pressure to “lift” the surface contaminants. Check the rag surface to ensure the cleaning is effective. Rotate the cloth surface to ensure clean cloth is doing the work. Continue until the cloth is picking up no more contaminants.
  3. Immediately wipe down freshly cleaned area with a clean dry cloth. The cleaning solvent must be removed before dry or a residue may be left behind that may interfere with the sealant adhesion.
  4. Change to clean cloths as needed to ensure contamination is not reintroduced to surface being prepared.

This procedure is valid for cleaning all sealant applications to non-porous surfaces but is not a substitute for priming when indicated.

For more information about our sealants, sealant applications, or questions regarding this blog post, we recommend contacting our Technical Service Department. They can be reached by email at or by phone at (800) 523-6688.


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