Common Epoxy Application Problems To Avoid

Adhesion Problems

Even though epoxy has very good adhesion to concrete or metal surfaces, there are a number of reasons for poor adhesion of the epoxy to a concrete floor, including:

• insufficient surface preparation
• contamination of the material with oil, dirty solvent or dirty tools
• improper mixing of the two components
• wet or greasy floors

If the areas with defects don’t cover the entire floor, areas of poor adhesion can be defined by tapping over the area with a hammer. A hollow sound indicates lack of adhesion. You should mark out suspected areas a few inches outside the limits of poor adhesion and cut through the topping, then remove the damaged area by light mechanical hammers to establish the cause of adhesion. Make sure that the concrete is free of grease, etc., and reapply the epoxy coating. It is important to know that epoxies have relatively low peel strength and in instances of poor adhesion, attempting to remove the patch by chiseling can lift a large area of floor out, even where adhesion is still good. Such lifting can be limited by a “stop-cut”.

Nonuniformity

This is dependent on the application technique rather than with the material itself. The broadcasting of the colored quartz aggregate (or aggregate for non-slip) must be done carefully to avoid any rough area formation. Lack of uniformity can also caused by poor premixing of component A (containing the colorants). One should avoid over-rolling the coating and apply it evenly and at the right thickness. Another reason that may cause discoloration is back rolling or excessive rolling after the material starts to set.

Disintegration

This is rare and only happens upon exposure to severe chemicals, particularly before the epoxy full cures. Harsh chemicals such as acetone, methyl ethyl ketone, glacial acetic acid, paint stripper and benzyl alcohol should be kept away from the floor since the damage is irreversible. Spillages should be cleaned immediately.

Contamination

Contamination can cause the epoxy to develop fish eyes, which are spots where the epoxy seems to repel or stay away, leaving a black spot. The most common cause is when unseen stains of oil or grease are present on a concrete slab. It is important to prepare the slab thoroughly, washing and drying it before installation. It is important to note that contamination can also happen in between coats. Even if the first coating was perfect, if contamination happens on that first coating, the second coat may crawl. Keep anyone away from the floor after the first coating to prevent anything from contaminating that layer.

Soft Patches

One common cause of a tacky surface or soft patch is improper mixing ratios or poor mixing of materials. This can be confirmed whenever the material refuses to harden after a few days. The tacky material has to be removed, the surface cleaned and the coating reapplied.

This can happen in conditions of high humidity or in close proximity to a water source while the material is still curing. In this case, the epoxy coating is hardened and firm but has a tacky surface, or white residues (salts). This material can either be removed with a vinegar solution (diluted with water) or by sanding it. In both cases, it is recommended to reapply the coating to ensure a glossy finish since this treatment will remove the gloss as well.

All these problems can easily be avoided with just simple things like proper preparation, mixing, and installation. All the effort and work you or the installer would exert will be well worth it in the end.