ProTXcoat 305 Damp Seal

Low viscosity epoxy primer for green or wet concrete surfaces

ProTXcoat 305 Damp Seal is a low viscosity solvent free epoxy primer designed to seal and consolidate green or wet concrete and cementitious surfaces.

  • Penetrates deep into the concrete surface
  • Ensures high mechanical adhesion with ProTXcoat chemical & corrosion top coats
  • Cures at temperatures as low as 10 ̊C (50 ̊F)

Typical applications
Penetrating primer for green or wet concrete and cementitious surfaces such as, internal & external tanks surfaces, floors, structural concrete.


Penetrating primer for green or wet concrete and cementitious surfaces such as, internal & external tanks surfaces, floors, structural concrete.

Existing Concrete

  1. If the concrete surface is contaminated, pressure wash using clean water.
  2. Clear any standing water from the surface of the concrete.

New Concrete

  1. Allow new concrete to cure for a minimum of 3-4 days and treat to remove any surface laitance.
  2. Lightly scarify the surface taking care not to expose the aggregate.
  3. Clean all dust and debris from the surface.

Prior to mixing please ensure the following:

  1. The base component is at a temperature between 15-25°C (60-77F°).
  2. The ambient & surface temperature is above 10°C (50F°).
  1. Transfer the contents of the Activator unit into the Base container.
  2. Using an electric paddle mixer, mix the 2 components until a uniform material free of any streaks is achieved.
  3. From the commencement of mixing the whole of the material should be used within 45 minutes at 20°C (68°F).

Brush or roller applications

  1. Pour the mixed material into a paint kettle or paint tray (this will maximise the usable life)
  2. Using a 50mm (2”) wide synthetic brush, stripe coat all edges, joints, corners and equipment with the mixed material. The stripe coat must be approximately 100mm (4”) wide, at 150 microns (6mil) wet film thickness.
  3. Once the stripe coat has cured sufficiently and is capable of being overcoated, apply the mixed product to all surfaces at 150 microns (6mil) wet film thickness. Leave to cure for a minimum of 8 hours at 20°C (68°F).
  4. Once cured, the coated surface must have a semi-gloss finish, any dull patches will be caused by excessive porosity in the concrete surface. Therefore a 2nd coat of 305 Damp Seal must be applied.
  5. Apply a 2nd coat of material at 150 microns (6mil) wet film thickness.

Spray Applications

  1. Spray application should be carried out by airless spray using a 30:1 ratio pump.
  2. Spray pressure of 2000psi and a tip size of 15-21 thou should be used.
  3. Apply the 1st coat of mixed product to all surfaces at 400 microns (16mil) wet film thickness.
  4. Once the 1st coat of material has cured sufficiently, approximately 30 minutes at 20°C (68F°), apply a 2nd coat of material to all surfaces at 400 microns (16mil) wet film thickness
Coverage Rates20ltrs (5.3 US gallon) of fully mixed product will give the following coverage rates
50m2 at 400 microns536ft2 at 16mil
Please note that the coverage rates quoted are theoretical and do not take into consideration the profile or condition of the surface being repaired.
Cure TimesAt 20°C (68°F) the applied materials should be allowed to harden for the times indicated below before being subjected to the conditions indicated. These times will be extended at lower temperatures and reduced at higher temperatures:
Touch Dry30 minutes
Minimum overcoating time30 minutes
Hard dry24 hours
Full cure7 days
Maximum overcoating timeIndefinite
Pack Sizes
This product is available in the following pack sizes20ltrs (5.3 US Gallon).
Single componentWhite or light grey (standard colours), various colours on request
Over-coating times
MinimumThe material can be over-coated as soon as it is touch dry, approximately 30 minutes at (20°C (68°F).
Storage Life5 years if unopened and store in normal dry conditions (15-30°C/ 60-86F°)
Other Technical Documents
Safety Data Sheets ProductSingle component material
Specification Sheet QuickTechnical Performance Information
Application guideRoller & Spray applications

Please ensure good practice is observed at all times. Protective gloves, goggles & a disposable coverall must be worn during the mixing and application of this product. Before mixing and applying the material ensure you have read the fully detailed Safety Data Sheet.

The data contained within this Technical Data Sheet is furnished for information only and is believed to be reliable at the time of issue. We cannot assume responsibility for results obtained by others over whose methods we have no control. It is the responsibility of the customer to determine if the product is suitable for use. ProTXcoat accepts no liability arising out of the use of this information or the product described herein.