Mold Prep

• Base Layer: All-purpose ready-mixed joint compound is a good choice for both EPS and XPS. It provides a solid base and adhesive for other materials. Look into one that does self leveling

  • Priming: While not always necessary, priming with a suitable primer can improve adhesion.

  • Drying Time: Allow the compound to dry completely before applying additional coats.

Release Agents

• Frekote 770

• Wax: Apply in multiple coats (3-4) for optimal release.

  • Partial Paste #2 mold release wax, TR mold release wax

  • Only for specific scenarios

• PVA Release Agents:

  • Mold release from PTM&W, Partall Coverall Film PVA release agent

• Alternative: CR1 Easy-Lease Chemical Release Agent:

  • Apply with a cloth for better visibility and control.

  • Apply multiple layers for enhanced release.

• Silicone-Based Release Agents: These agents provide excellent release properties, especially for complex geometries.  

• Fluoropolymer-Based Release Agents: These agents offer superior release properties and can withstand higher temperatures.

• Dry Film Release Agents: These agents are applied as a powder and can be used in conjunction with other release agents for added protection.

Mold Surface Preparation

• Sanding and Polishing: Smooth the mold surface to reduce the risk of air pockets and imperfections in the finished part.

• Vacuum Bagging: Use vacuum bagging to ensure proper consolidation of the carbon fiber and resin, resulting in a stronger and more consistent part.  

• Post-Curing: After curing, sand and polish the part to remove any excess resin or imperfections.

Testing and Considerations

• Curved Structures: Test all release agents on curved structures to mimic the car's shape, especially crevices.

• Demolding Issues: Residue or difficulty demolding often indicates improper prep or cleaning.

• Consistency: Perform multiple tests of each product to assess its reliability.

PVA Replacements:

Silicone-Based Products

Pros:

• Excellent release properties, even for complex shapes.

• Can withstand high temperatures.

• Easy to apply as sprays or waxes.

Cons:

• Can be more expensive than other options.

• May require cleaning to remove residue from finished products.

Wax-Based Products

Pros:

• Cost-effective.

• Suitable for a wide range of applications.

• Can be applied by brushing or spraying.

Cons:

• May not provide as strong a release as silicone-based products.

• Can be messy to apply.

Fluoropolymer-Based Products

Pros:

• Exceptional release properties, even for difficult materials.

• Resistant to chemicals and high temperatures.

Cons:

• Can be expensive.

• May require specialized equipment for application.

Silicone is the best option…

• Silicone's excellent release properties make it ideal for these materials, ensuring clean and easy separation of the finished product from the mold.

• Silicone can withstand high temperatures often used in curing carbon fiber composites, preventing premature release or damage to the part.

• Silicone is compatible with both materials, providing effective release without causing any adverse reactions.

Specific products to consider:

• Aerosol sprays: Convenient for quick application and even coverage.

• Waxes: Provide a more durable coating, suitable for multiple uses.

Fillers / Coatings:

Fillers:

Typically added to a resin or other material to improve its properties. Can enhance strength, stiffness, weight reduction, or surface finish.

Coatings:

Applied to a surface to protect, enhance, or modify its properties. Can provide a barrier against moisture, chemicals, or abrasion.

Polyethylene Foam:

• Fillers:

  • Glass Flakes: Provide excellent dimensional stability and heat resistance.

  • Talc: Improves surface finish and reduces mold wear.

  • Carbon Black: Can be used to color the mold and improve heat dissipation.

• Coatings:

  • Epoxy Coatings: Offer a durable, chemically resistant surface.

  • Silicone Coatings: Provide excellent heat resistance and release properties.

  • Mold Release Agents: Prevent the composite from sticking to the mold.

Carbon Fiber Composites:

• Fillers:

  • Carbon Fibers: Enhance strength, stiffness, and weight-to-strength ratio.

  • Glass Fibers: Provide additional strength and stiffness at a lower cost.

  • Wood Flour: Can be used to improve impact resistance.

• Coatings:

  • Epoxy Coatings: The most common choice for carbon fiber composites, offering excellent strength, stiffness, and chemical resistance.

  • Polyurethane Coatings: Can provide a tough, durable surface.

  • Fluoropolymer Coatings: Offer excellent chemical resistance and non-stick properties.

Used as fillers or coatings for the mold or the part being produced. They provide structural support, improve surface finish, or enhance the properties of the final product.

Sealants:

Epoxy Resin: A versatile adhesive that can bond to various surfaces and provide a strong, durable seal.  

Silicone Caulk: Offers excellent weather resistance and flexibility, making it suitable for outdoor applications.  

Butyl Rubber Sealant: A self-adhering sealant with good resistance to chemicals and moisture.  

Vacuum Bag Sealant: Specifically designed for vacuum bagging applications, these sealants are often pre-cut strips or rolls for easy application.

Uused for creating a seal between the vacuum bag and the mold. They are adhesives or sealants designed to prevent air leakage during the vacuum bagging process.

Pay Close Attention To:

Adhesion: The sealant should have good adhesion to both the carbon fiber composite and the foam mold.

Durability: The sealant should be able to withstand environmental conditions, such as temperature fluctuations, moisture, and chemicals.

Flexibility: If the composite will be subjected to flexing or vibration, a flexible sealant may be necessary.

Epoxy Resin - fibreglast.com

System 1000 or 2000 Laminating - High Strength Room Temp:

• Provides good strength; however, 4500 infusion or 4600 (or 3000 or 3300) high temp infusion provides even more strength when cured at controlled conditions (18 to 24 hours at around 77 °(F).

• 10 to 25 pot life

• Cured parts have a high heat resistance

System 4500 Infusion - Low Viscosity Infusion:

• Used with the infusion process, drawn into the mold with a vacuum

• Ensures good penetration into the fiber layers

• Cures overnight at 77 °(F), then the bag and infusion materials can be removed from the laminate and the part can be sanded or trimmed as required.

• Full cure with these two hardeners will be achieved in 4 to 6 days at normal room temperature. A heat cure will shorten the curing time of System 4500 Infusion Epoxy.

• If using a laminate, place in an oven for 8 to 10 hours at 180°(F)

System 4600 High Temp Infusion - High Temp Low Viscosity Epoxy:

4500 -

• Designed for high temp applications

• Low viscosity infusion process

• Will gel in 18-24 hours at 77°(F).

• Typical post cure would be: follow gel up with an oven post cure of 3 to 4 hours each at 150°(F) and 250°(F), followed by a final cure of at least 8 hours at 300°(F)

3000 -

• This epoxy laminating system will gel hard in 24 to 36 hours at 77°(F).

• Oven post-cure is strongly recommended for maximum stability. But only for applications of continuous service temperature is over 250°(F)

3300 -

• This epoxy laminating system will gel hard in 24 to 36 hours at 77°(F).

• Oven post-cure is strongly recommended if frequent heating and cooling cycles and cutting/drilling into the structure

3M:

Premium Mold and Tooling Compound

• Compound removes sanding scratches in tooling gelcoat

Fillers:

3M Microspheres - Filler:

• These tiny hollow particles help reduce weight and improve dimensional stability.

3M Nanoparticles - Filler:

• Even smaller than microspheres, nanoparticles can enhance mechanical properties like strength and stiffness.

3M Fiber - Filler:

• Short fibers can be added to improve toughness and impact resistance

3M Glass Bubbles - Filler:

• These tiny hollow spheres can be added to carbon fiber composites to reduce weight, improve dimensional stability, and enhance thermal insulation.

Sealants:

3M Scotch-Weld Structural - Adhesive Sealant:

• These adhesives are known for their strength and durability.

• Can be used to bond the carbon fiber composite to the foam mold, ensuring a secure and long-lasting connection.

3M DP-100 Structural - Adhesive Sealant:

• This adhesive is a popular choice for bonding various materials, including composites. A good balance of strength, durability, and ease of use.

3M Scotch-Weld - Polysulfide Sealants:

• These sealants are highly resistant to chemicals, weathering, and temperature extremes.

• Often used in marine and industrial applications, making them suitable for outdoor environments.

3M - Silicone Sealants:

• While not as chemically resistant as polysulfide sealants, silicone sealants offer excellent weatherability and flexibility.

• Can be a good choice for sealing gaps and joints in carbon fiber composites, especially in applications where a more flexible sealant is needed.

Coatings/Adhesives:

3M Hi-Tack Composite Spray Adhesive 71:

• This spray adhesive is specifically designed for composite materials, providing a strong and reliable bond.

3M Scotch-Weld™ Multi-Material Composite Urethane:

• This adhesive is a great choice for bonding carbon fiber composites to a variety of other materials, including metals and plastics.

3M Duratec Sunshield:

• This clear coat is designed to protect carbon fiber composites from UV radiation, weathering, and chemicals. It also provides a glossy finish that enhances the appearance of the composite.

Started: 09/06/2024

Edited 09/07/2024

Edited 09/14/2024