Rustproofing Primer and Coating for Steel

Fibre-Prime

Water-based, polymer-modified cement slurry with corrosion inhibitors for steel reinforcement and concrete repair systems.

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Technical basis FIBRE-PRIME
  • Contains corrosion inhibitors active on both anodic and cathodic corrosion sites.
  • Bonds to wet steel and protects reinforcing steel before compatible repair mortars are applied.
  • Can be used as a rustproofing primer before cementitious coatings or as a protective coating in immersed and non-immersed applications.

Decision Summary

When to specify Fibre-Prime

  • Reinforcement is exposed or has corrosion risk after breakout.
  • The repair mortar needs a compatible bonding layer.
  • The repair is in an environment where water and chlorides may return.

Core Uses

Rebar protection, rustproofing primer, and repair bonding layer

Reinforcement Corrosion Protection

FIBRE-PRIME is applied when exposed reinforcement is part of a concrete repair. Without a corrosion-control layer, corrosion continues under the patch and breaks the repair from inside, even if the surface initially looks restored.

Anodic and Cathodic Inhibition

The formulation contains corrosion inhibitors active on both anodic and cathodic corrosion sites, so it targets the electrochemical process rather than only covering the steel mechanically.

Bonding Slurry for Repair Mortars

FIBRE-PRIME also acts as a cementitious bonding slurry for compatible Fibre-Patch repair mortars, tying steel protection, substrate bond, and repair mortar placement into one sequence.

Comparison Block

How the material changes the specification

Repair Without Steel Treatment: Common Limitations

  • Loose rust may be removed, but the electrochemical corrosion process can continue.
  • New mortar hides the steel, making early warning signs harder to see.
  • The patch can debond as expanding corrosion products build pressure beneath it.

FIBRE-PRIME: Practical Value

  • Treats exposed steel before the repair mortar closes the section again.
  • Provides corrosion inhibition and a compatible bonding slurry in the same repair sequence.
  • Supports longer repair life where water, chlorides, carbonation, or H2S exposure can return.

Technical Data Table

Reported product data and test references

PropertyValueSource / test
Wet steel bond2.6-3.5 MPaProduct data sheet / Gemite technical data
VOC0 g/LProduct data sheet / Gemite technical data
Corrosion protectionAnodic and cathodic inhibitorsProduct data sheet / Gemite technical data
Freeze-thaw mass loss0% in ASTM C666 testingProduct data sheet / Gemite technical data

Application / Specification Notes

Preparation, installation, curing, and limitations

Substrate Assessment

Confirm substrate soundness, contamination, moisture condition, cracks, exposed reinforcement, and service exposure before selecting the final Gemite system.

Application Planning

Follow the current product data sheet and guide specification for mixing, surface preparation, application thickness, curing, and environmental limits.

Permanent System Build-Up

Where the product is used as a repair or first-response material, complete the sequence with the compatible waterproofing, repair, or protection layers required by the project.

System Compatibility / Related Product Notes

Related Gemite system interfaces

FIBRE-PRIME

Use on exposed reinforcement where corrosion protection is required before repair mortar placement.

FIBRE-PATCH GP / OV

Use repair mortars to rebuild damaged concrete before final waterproofing or coating layers.

CEM-KOTE Systems

Select Cem-Kote waterproofing or protection products according to water pressure, movement, chemical exposure, traffic, and potable-water requirements.

FAQ

Specification questions

Can Fibre-Prime be skipped to reduce repair cost?

Skipping corrosion protection can make the repair cheaper on day one and weaker in service. If steel is exposed or corrosion risk remains, Fibre-Prime is part of the durability strategy.

How clean should the reinforcement be?

Loose rust, dust, laitance, and friable material must be removed so the coating can contact sound steel and concrete.

Can it also work as a bonding agent?

Yes. It can be used as a cementitious bonding slurry for compatible repair mortars when applied to a properly prepared substrate.

Can Fibre-Prime be used only as a bonding slurry?

Yes, it can work as a bonding slurry for compatible repair mortars, but its most important role in structural repairs is corrosion protection where steel reinforcement is exposed.

Does reinforcement need to be perfectly dry?

No. Fibre-Prime is designed to bond to wet steel, but loose rust, dust, laitance, and friable material still need to be removed so the coating contacts sound steel and concrete.

Next Step

Need technical guidance for this system?

Send the substrate condition, exposure, traffic, crack profile, and coating sequence. Gemite can help confirm whether this product fits the project conditions.

Request Technical Guidance

Or contact us: office@gemite.tech · +40 232 273 031