loctite b 15

Loctite B-15

Applications:Mould preparation
Drying time between coats, @ 20.0 °C:30.0 min.
Finish reflection:Matte
Full cure time, @ 20.0 °C:24.0 hr.
Key characteristics:Solvent based

Overview

Loctite B-15 (Loctite Frekote B-15) is a one-part, solvent-based polymer mold sealer designed to restore and prepare composite and metal molds that suffer from micro-porosity, small scratches or surface imperfections.

Applied as a thin base coat, it:

  • Seals micro-porosity and fine defects in the mold surface

  • Provides a clear, colorless film that does not change the tool appearance1

  • Offers high thermal stability for elevated-temperature molding processes

  • Ensures no contaminating transfer to molded parts when correctly applied

Used in combination with Loctite Frekote release agents, B-15 acts as an excellent base coat, enhancing both release performance and mold life.

Key Features & Benefits

  • 1-part, solvent-based polymer sealer
    Ready-to-use liquid; no mixing required. Cures at room temperature, simplifying mold preparation.

  • Seals porosity, scratches and imperfections
    Penetrates and seals micro-porosity, small surface scratches and minor defects, restoring a smooth, sealable surface on composite and metal tools.

  • High thermal stability
    Formulated for elevated molding temperatures, maintaining film integrity over multiple cycles.

  • No contaminating transfer
    Properly cured B-15 leaves no contaminating transfer to molded parts, helping maintain surface quality and downstream bonding/painting.

  • Ideal base coat for Frekote release systems
    Used before Frekote release agents to improve release performance, reduce sticking and extend mold life.

  • Clear, colorless finish
    Maintains good visibility of the mold surface and repairs; useful for inspection and high-quality composite work.

Typical Applications

Loctite B-15 is used as a mold sealer / mold preparation coating for:

  • Composite molds

    • Carbon fiber, fiberglass and other advanced composite tools

    • Tools used in RTM, vacuum bagging, hand lay-up and autoclave processes

  • Metal molds

    • Aluminum and steel molds with micro-porosity or light scratching

    • Rotational molding and other processes where mold porosity affects release

  • Aerospace, automotive and industrial components

    • Composite panels, fairings, covers and structural parts

    • High-value tools where extended mold life and consistent release are critical

How to Use Loctite B-15

Always follow the current Henkel TDS/SDS and your internal process specification. Steps below are a general overview.

Step 1 – Mold cleaning

  1. Thoroughly clean the mold to remove waxes, old release agents, oils, resins and contaminants.

  2. Use a recommended mold cleaner / solvent and lint-free cloths.

  3. Ensure the surface is dry and at the recommended temperature before sealing.

Step 2 – Application

  1. Apply Loctite B-15 with a clean cloth, pad or spray, depending on your procedure.

  2. Work in small sections, wiping a thin, even film over the surface.

  3. Avoid heavy puddles; the goal is to wet and seal the surface, not build a thick coating.

Step 3 – Multiple coats

  1. Typically, multiple light coats are applied to fully seal porous areas (refer to TDS for number and timing).

  2. Allow each coat to dry / flash off at room temperature before applying the next.

Step 4 – Cure

  1. After the final coat, allow B-15 to cure fully at ambient temperature for the time specified (often up to 24 hours).

  2. Once cured, the mold is ready for application of the chosen Frekote release agent or for the next stage in your process.

Step 5 – Release agent application

  • Apply the Frekote release coating on top of B-15 according to its own instructions.

  • Together they create a sealed, low-adhesion surface that supports multiple molding cycles.

Safety & Handling

  • Loctite B-15 is solvent-based and typically flammable – keep away from heat, sparks and open flames.

  • Use only in a well-ventilated area; avoid breathing vapours.

  • Avoid skin and eye contact; wear appropriate PPE (gloves, goggles, protective clothing).

  • Do not allow product to enter drains or natural waterways.

  • Store in the original, tightly closed container in a cool, dry place, away from ignition sources.

Always consult the latest Safety Data Sheet (SDS) before use.

FAQs

Q1: What is Loctite B-15 mainly used for?
Loctite B-15 is mainly used as a mold sealer for composite and metal tools with micro-porosity, fine scratches or surface imperfections, providing a sealed base for release agents.

Q2: Is Loctite B-15 a release agent by itself?
No. It is primarily a sealer, not the final release layer. It is usually used first, followed by a Frekote release agent to achieve optimum part release and multi-cycle performance.

Q3: On which substrates can I use B-15?
B-15 is formulated for composite molds (e.g. carbon, glass fiber tools) and metal molds such as aluminum and steel. Always test on any unusual substrate before full-scale use.

Q4: Will B-15 change the appearance of my mold surface?
No significant change is expected. It forms a clear, colorless film, maintaining visibility of the mold surface for inspection and finishing.

Q5: Does Loctite B-15 transfer onto molded parts?
When correctly applied and fully cured, B-15 provides no contaminating transfer to the molded parts, helping protect surface quality and downstream painting or bonding.

Q6: What temperature range can it withstand?
B-15 is designed with high thermal stability for typical composite molding temperatures; always check the current TDS for specific temperature limits in your process.

Q7: How often do I need to reapply B-15?
You generally reapply B-15 when the mold surface shows wear, porosity exposure or after refurbishment. Routine cycles are usually handled by the release agent alone; B-15 is used when re-sealing is required.

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