E155CL Damp Condition Clear Epoxy Primer | Moisture Tolerant | Quick Cure | Low Temp 45° | Flexible

Physical Properties

Physical Properties Chart

Bond Strength

Method: ACI 403

Result: 325 PSI (Concrete Fails)

Dry Heat Resistance

Method: ASTM D2485

Result: 200°F

Flexibility: Conical Bend Mandrel

Method: ASTM D522 180° Bend

Result: Passes 1/8″

Impact Resistance

Method: ASTM D2794

Result: Direct- 160 in/lb

Result: Direct- 160 in/lb

Pencil Hardness

Method: ASTM D3363

Result: 2H

Tensile Elongation

Method: ASTM D638-60

Result: 10%

Tensile Elongation

Method: ASTM C 190-99

Results: 3500psi

Water Absorption

Method: ASTM D570

Result: .1% max

COVERAGE RATE

Cure and Recoat Information

As a primer for epoxy mortars, toppings and 100% solids resins and 100% solids coatings, E155 should be topcoated while still tacky. This will be 30 min. – 1-1/2 hours at 75°F when the E155 is applied at a rate of 150-250 sq. ft. per gallon.

When used as a primer for less than 100% solids solvent coatings, E155 must be dry to touch.  This is typically 4 hours minimum and 6 hours maximum. If the recoat time is in excess of 6 hours, sanding with 80-100 grit open coat paper is required before applying finish coat.

Allow 24 hours for foot traffic and 72 hours for heavy traffic with good ventilation before putting floor back into service.

MIXING AND APPLICATION INSTRUCTIONS

SURFACE PREPARATION

In all cases of surface preparation, the pH should be checked. A pH reading of 7.0 to 8.5 is acceptable. Also, a Water Dissipation Test should be made on random areas of the floor to determine if the proper degree of porosity has been achieved. Before the installation of any Gulf Coat Paint Products, the substrate should be examined for moisture. Test for moisture vapor transmission using ASTM F-1869 Standard Test Method for Measuring Moisture Vapor Emission Rate of Concrete Subfloor using Anhydrous Calcium Chloride. The maximum allowable rate is 3 lbs. per 1,000 square feet per 24 hours. Test for relative humidity in concrete floor slabs using Probes according to ASTM F-2170. This test measures the presence relative humidity of the slab below the surface. The maximum relative humidity should be below 80%.

New concrete must be cured at least a minimum of 28 days before applying a coating. On-grade slabs must have moisture vapor barrier in place. All laitance, sealers, efflorescence, chemical contaminants, grease, oil and other foreign material must be removed. The prepared surface must be clean, dry and structurally sound.  Ideal preparation includes mechanical preparation by means of shot blasting or diamond grinding to achieve a CSP-2 or CSP-3 profile, in accordance with the International Concrete Repair Institute (ICRI). The profile should reflect something similar to a 60-100 grit sandpaper.

Due to the low viscosity of the E155CL Epoxy Primer an acid etch is acceptable preparation as long as it is done correctly with proper neutralization of the acid and a thorough rinsing is performed.  For an acid etch preparation we suggest our E760CE Muriatic Replacement as a safer alternative.

If the substrate is not properly prepared and the appropriate profile is not achieved, failure of the product to adhere to the substrate may occur.

Old concrete surfaces must be structurally sound. Any unsound areas must be repaired prior to proceeding with the resinous installation. For proper patching and repairing, use CF-615 and/or PC-1000 with graded aggregate. Remove existing paint and loose concrete by rough sanding, sandblasting, high pressure water cleaning, shot blasting or grinding. In some cases where plant conditions allow, a stripper may be used to remove excessive build-up of paints or sealers.

MIXING INSTRUCTIONS

E155 is prepared by mixing 1 part Base (Part A) to 1 part Hardener (Part B) with a variable speed drill with a Jiffy mixer. E155 should be used without any induction time. Do not thin, use as supplied.

For best mixing results and proper blending of parts A and B, recommend a Jiffy Mixer style drill mixer.

Use of an improper drill mixer can result in curing problems if the hardener also called activator (Part B) is not thoroughly blended with the resin (Part A) which can cause some areas on your floor to remain soft and not harden properly.  DO NOT USE A PAINT MIXER.  Most mixing problems described above can be traced back to using a paint mixer..  DO NOT HAND MIX as this approach can result in the same problems as using a paint mixer.

APPLICATION PROCEDURE 

For best results, apply by roller, using a medium nap, phenolic core roller cover. Apply an even, uniform, wet film while working material into surface. Do not allow material to puddle. Spread rate will be approximately 150 to 250 sq. ft. per mixed gallon, depending upon porosity of concrete surface.

E155 may also be sprayed, but then should be “back-rolled” to produce a uniform coat. For small areas and “cutting in” use pure bristle brush. Do not apply to surfaces below 45°F or above 100°F.

For safety and product curing, proper ventilation is necessary throughout application and cure. When using pigmented Finish Coats, be sure the batch numbers are all the same to provide a uniform color.

RECOAT TIME

As a primer for epoxy mortars, toppings and 100% solids resins and 100% solids coatings, E155 should be topcoated while still tacky (not gooey). This will be 30 min. – 1-1/2 hours at 75°F when the E155 is applied at a rate of 150-250 sq. ft. per gallon.

When used as a primer for less than 100% solids coatings, E155 must be dry to the touch (does not have to be tack free). Under the same conditions this will be 4 hours minimum and 6 hours maximum. If the recoat time is in excess of 6 hours, sanding with 80-100 grit open coat paper is required before applying finish coat.

CAUTIONS

E155 is flammable. Keep away from all sources of ignition during storage, mixing, application and cure. The Hardener (Part B) either alone or when mixed with Base (Part A) can cause eye and skin burns as well as allergic reactions. When spraying, the use of goggles, fresh air masks or NIOSH approved respirators, protective skin cream, and protective clothing is recommended as a standard practice. This product is sold without warranty as to performance expressed or implied. Users are urged to make their own tests to determine the suitability for their particular conditions.

SEE MATERIAL SAFETY DATA SHEET FOR FULL SAFETY PRECAUTIONS.  FOR PROFESSIONAL AND INDUSTRIAL USE ONLY  KEEP AWAY FROM CHILDREN.  NOT FOR RESIDENTIAL USE NOTICE TO BUYER: DISCLAIMER OF WARRANTIES AND LIMITATIONS ON OUR LIABILITY We warrant that our products are manufactured to strict quality assurance specifications and that the information supplied by us is accurate to the best of our knowledge. Such information supplied about our products is not a representation or a warranty. It is supplied on the condition that you shall make your own tests to determine the suitability of our product for your particular purpose. Any use or application other than recommended herein is the sole responsibility of the user. Listed physical properties are typical and should not be construed as specifications. NO WARRANTY IS MADE, EXPRESSED OR IMPLIED, REGARDING SUCH OTHER INFORMATION, THE DATA ON WHICH IT IS BASED, OR THE RESULTS YOU WILL OBTAIN FROM ITS USE. N0 WARRANTY IS MADE, EXPRESSED OR IMPLIED, THAT OUR PRODUCT SHALL BE MERCHANTABLE OR THAT OUR PRODUCT SHALL BE FIT FOR ANY PARTICULAR PURPOSE. NO WARRANTY IS MADE THAT THE USE OF SUCH INFORMATION OR OUR PRODUCT WILL NOT INFRINGE UPON ANY PATENT. We shall have no liability for incidental or consequential damages, direct or indirect. Our liability is limited to the net selling price of our product or the replacement of our product, at our option. Acceptance of delivery of our product means that you have accepted the terms of this warranty whether or not purchase orders or other documents state terms that vary from this warranty. No representative is authorized to make any representation or warranty or assume any other liability on our behalf with any sale of our products. Our products contain chemicals that may CAUSE SERIOUS PHYSICAL INJURY. BEFORE USING, READ THE SAFETY DATA SHEET AND FOLLOW THE PRECAUTIONS TO PREVENT BODILY HARM.

What is E155CL epoxy primer used for?

E155CL is a moisture-tolerant, two-component epoxy primer designed for damp or green concrete surfaces. It is commonly used as a base coat under epoxy, polyurethane, polyaspartic, and polyurea systems or as a standalone clear concrete sealer.

Typical applications include:

• Garage floors
• Warehouse and industrial floors
• Loading docks and shop floors
• Tank pads, sumps, and secondary containment
• Exterior walkways and slabs

Can E155CL be applied to damp concrete?

Yes. E155CL is specifically formulated to bond to damp or moisture-containing concrete, making it ideal for projects where drying time is limited.

Unlike standard primers that can fail on wet slabs, moisture-tolerant epoxies are designed to prevent delamination, blistering, and adhesion loss in high-moisture environments.

Why should I use a moisture-tolerant epoxy primer instead of a standard primer?

Standard primers often fail when moisture is present, leading to:

• Peeling or delamination
• Bubbling or blistering
• Poor adhesion

E155CL solves this by:

• Penetrating deeply into damp concrete
• Creating a strong bond even in high humidity
• Reducing vapor-related coating failures

Moisture-resistant primers are considered essential for fast-track construction, below-grade environments, and humid climates.

How does E155CL help prevent concrete outgassing?

E155CL has a low viscosity and deep penetration, which helps seal pores in the concrete. This significantly reduces outgassing, a common issue that causes bubbles in topcoats.

Can E155CL be used as a clear concrete sealer?

Yes. E155CL can be used as a standalone clear sealer to:

• Reduce dusting and spalling
• Protect against water and chemical intrusion
• Extend the life of concrete surfaces

For best results, two coats are recommended when used as a sealer. Note: E155CL Epoxy is not water clear but is unpigmented and has an amber color.

How fast can you recoat E155CL?

E155CL is a fast-curing epoxy primer, allowing for:

• Recoat with 100% solids epoxy: 30 minutes to 1.5 hours
• Recoat with solvent-based coatings: 4–6 hours

This makes it ideal for same-day coating systems and fast project turnaround. Note: Higher or lower temperatures from 75F will affect cure schedule. 

What temperature can E155CL be applied at?

E155CL can be applied in temperatures as low as 45°F, making it suitable for cool weather installations and seasonal work.

What surfaces can E155CL be applied to?

E155CL is primarily used on:

• Concrete
• Masonry

It is designed to penetrate porous substrates, creating a strong bonding surface for coatings.

How much coverage do you get with E155CL?

Coverage typically ranges from:

• 150–250 sq. ft. per gallon

Actual coverage will vary based on surface porosity and profile.

What makes E155CL different from other epoxy primers?

E155CL stands out because it combines:

• Moisture tolerance (apply on damp concrete)
• Fast cure and quick recoat
• Deep penetration for superior adhesion
• Flexibility to handle substrate movement
• Low permeability to block water and chemicals

Does surface preparation still matter if the concrete is damp?

Yes. Even with a moisture-tolerant primer:

• Remove standing water, oil, and contaminants
• Use acid etching or diamond grinding for best adhesion

Proper prep ensures maximum performance and coating longevity.

What coatings can be applied over E155CL?

E155CL is compatible with most high-performance systems, including:

• 100% solids epoxy coatings
• Polyurethane coatings
• Polyaspartic systems
• Polyurea coatings

For severe chemical environments, topcoat with E517 Epoxy Mastic. For additional support choosing the best topcoat for YOUR project reach out at 630-675-4509 or [email protected].

Is E155CL good for moisture problem floors?

Yes—E155CL is an excellent solution for:

• Damp slabs
• Below-grade concrete
• High humidity environments
• Fast-track construction projects

It acts as a moisture-tolerant bonding layer, helping coatings perform even in challenging conditions.

Does E155CL have color?

E155CL is clear (amber tint). It is not water-clear but remains unpigmented, making it ideal when a transparent primer or sealer is desired.

What is the mix ratio for E155CL?

E155CL uses a simple:

• 1:1 mix ratio by volume

This makes it easy to measure and apply in the field.

How long before the floor can be used?

Typical cure times:

• Light foot traffic: 24 hours
• Heavy service: 72 hours

Proper ventilation will help achieve optimal cure.