Concrete is a versatile construction material, but one with several disadvantages. It’s an alkaline substance, and as such not only is highly susceptible to chemical attack, but also is chemically threatening to alkali-sensitive materials, such as alkyd-based paints. The porosity of concrete allows potentially damaging agents to penetrate it more readily, increasing the likelihood of serious damage. Also, concrete has relatively poor abrasion resistance and cohesive strength, which allows physical deterioration and leads to difficulty in daily cleaning, which ultimately leads to failure.
Of course, concrete can be protected. Its inadequacies can be reduced, and years can be added to its service life by coating it with a material capable of withstanding the stresses put on it. Many types of coatings are available for use on concrete, but none, however is as versatile as POR-15.
Diversity
of POR-15 for Concrete Protection
It might seem to some that the many different expectations of end users for concrete coating performance would make it very difficult to find one coating technology capable of meeting their wide-ranging needs. But POR-15 is versatile. It is used as a primer or sealer, patching material or topcoat. POR-15 is used as a moisture barrier and a heavy-duty wear surface. It is available as a single component moisture-cure or a two-component reactive formulation. It can be brushed, rolled, sprayed, squeegeed, or trowelled.
POR-15 is an outstanding moisture-curing single component formulation, highly recommended to prime and seal porous substrates. POR-15 is a very effective dust binding impregnate as well as sealer for cement and other substrates because it can protect the substrate from water, chemicals, deicing salt, and mineral oils. Because of its high degree of flexibility, POR-15 can also serve as a bridge over cracks. As a corrosion-resistance primer, POR-15 contains aluminum pigments that provide barrier protection.
POR-15 is tack-free after 3 – 5 hours and through hard in 72 hours, after which a film with a thickness of 40 um has a pendulum impact hardness of about 170 seconds. The abrasion loss (Taber Abrader CS 10, 1000 rpm, 1000 g) is about 5 mg. A fully cured POR-15 film is characterized be remarkable hardness and flexibility, and by good resistance to water and chemicals, though it yellows under light when not top coated. POR-15 is a good binder for synthetic resin-based concrete. A mixture consisting, for example, of quartz sand and POR-15 cures from the surface by contact with atmospheric humidity. Pronounced yellowing and chalking must be expected in outdoor applications; therefore, it is recommended that the coating be top coated with POR-15 2-component coatings (HARDNOSE Paints in 8 colors).
Comparison
of POR-15 with Epoxy coatings
While many epoxies may equal the hardness of POR-15, serious differences exist. Epoxies have a far greater tendency to chalk than does POR-15, and as they age, epoxies become brittle and often crack. POR-15, strengthened by moisture, remains flexible permanently. Epoxies once mixed, cure rapidly, and two-component mixing often tends to be wasteful with a huge loss factor because pot life is limited and cure can take place before the material is used up. Because of its tighter molecular structure, POR-15 is a far superior moisture barrier than any presently existing epoxy system.
Application
Procedures / Surface Preparation
Surface to be
coated should be clean and dust free. Newly
laid concrete should be swept and vacuumed thoroughly.
Grease or oil spots should be scrubbed with POR-15 Marine Clean, then rinsed
with water. Older concrete surfaces
should be treated with a muriatic acid solution (HCL) of about 10% to remove
calcium salts and to etch the concrete. After
the contaminated areas are treated and cleaned, the entire concrete surface
should be washed thoroughly with water and then dried.
If oil or grease spots are fresh and pronounced, dry the area first and
then treat them with a coat of white shellac before applying POR-15.
The use of portable equipment may be required. POR-15 CAN ONLY BE
APPLIED TO A CONCRETE SURFACE THAT IS BONE-DRY TO A DEPTH OF TWO (2) INCHES.
If there are painted areas, the paint should be stripped off and the
stripped area should be treated with muriatic acid.
If large areas of concrete are painted and it isn’t practical to remove
the paint, a small test area should be coated with POR-15 to determine the
adhesion quality, which in most cases should be acceptable.
If you are uncertain of how to proceed in a special area, call POR-15
directly at 1-800-689-7504 or email us at techsupport@por15canada.com.
Application
Procedures / Applying POR-15
If you are
applying POR-15 Rust Preventative Paint to a concrete surface in an enclosed
area, you MUST use an
air-supplied respirator for protection. You
must also use an air-supplied respirator at all times when spraying POR-15.
If the application is by roller or brush in a well-ventilated area, an
organic vapor particulate respirator, NIOSH/MSHA approved should be used.
Under no circumstances will a paper dust mask alone provide adequate
protection when applying POR-15.
Surface to be coated must be bone-dry. Apply in full, covering coats so that the concrete is saturated with POR-15. The paint will seep into the cracks and crevices and fill voids to provide maximum, permanent protection. Coverage will depend upon the surface tightness and quality of the concrete, but a general rule of thumb is about 350 square feet per gallon. A properly coated surface will always require a second coat. Read directions on can carefully for application details. If any moisture or water is mixed in any way with POR-15 before application (perspiration dripping into can, accidental spillage, etc.), POR-15 will begin to cure and may not stick properly to the concrete surface. Be very careful to avoid liquid contamination of any kind.