Fiberglass Mold Fabrication: Materials and Tools List

‌I. Structural Layer Materials

‌Plug (Master Model)

• High-Density Polyurethane Foam Board (e.g., SikaBlock® M1050/M1200) – Primary shape formation
• Epoxy Tooling Board/Paste Filler – Surface contour refinement
• Low-Temperature Epoxy Tooling Gelcoat (≥1.2 mm, 120°C service temp) – Chemical-resistant, high-gloss surface
• Surface Primer + Polishing Kit (P400-P2000 sandpaper, polishing compound) – Mirror finishing

‌Glass-back (Mold Structure)

• E-glass Surface Veil 30 g/m² – First layer after gelcoat, crack suppression
• E-glass Chopped Strand Mat 450 g/m² or 600 g/m² – Rapid thickness build-up
• E-glass Biaxial Fabric 0°/90° 800 g/m² – Primary load-bearing layer
• Epoxy Tooling Resin (Low-exotherm, low-shrinkage, e.g., Huntsman RIM135 + RIMH137) – Resin : Hardener ratio 100 : 30–40
• Epoxy Structural Adhesive – Mold section bonding/stiffener attachment
• Steel/Aluminum Reinforcing Frame (40×40 mm square tube) – Dimensional stability

‌Backing/Support

• High-Density Polyurethane Foam Blocks – Localized weight reduction
• Epoxy Foam Filler – Cavity filling, secondary weight reduction

‌II. Ancillary Layers (Single-use per infusion)

‌Release System

• Semi-Permanent Release Agent (Chemlease 15 Sealer + 16 Release)
• Mold Release Wax + Polyvinyl Alcohol (PVA) – Backup solution

‌Fiber Preform

• E-glass Triaxial Stitched Fabric 0°/+45°/-45° 1200 g/m² – Primary reinforcement
• E-glass Biaxial Fabric 0°/90° 800 g/m² – Local reinforcement
• Continuous Filament Mat 300 g/m² – Enhanced resin flow [^6]

‌Flow Media/Bleeders

• High-Permeability PE Flow Mesh 160 g/m² (MS-160) [^6]
• Bleeder Fabric 100 g/m² – Resin content control (30% ±3%)
• Perforated Release Film (0.05 mm, 5 mm hole spacing)
• Breather Fabric 50 g/m² – Vacuum bag protection

‌Vacuum Bagging & Sealing

• High-Temp Nylon Vacuum Bagging Film (≥120°C, 50–75 μm thickness)
• Butyl Sealant Tape 12mm×3mm – Perimeter sealing
• Vacuum valves, quick-disconnects, spiral hoses

‌III. Resin Infusion/Vacuum System

‌Resin

• Epoxy Infusion Resin (Low viscosity: 200–300 mPa·s @ 25°C, pot life 60–90 min)
• Hardener: Amine-based slow-cure system (24hr demold)

‌Plumbing

• Spiral Resin Delivery Hose Ø12mm + T-fittings – Main feed line
• 2L Resin Trap – Anti-siphon protection
• Vacuum Pump ≥5 m³/h, ultimate vacuum ≤ -0.095 MPa (-28 inHg)
• Vacuum Gauge + Pressure Regulator

‌IV. Tools & Consumables

• Precision Digital Scale (0.1g resolution) – Resin/hardener measurement
• Mixing Drill + Shear Impeller – Deaeration blending
• Aluminum/Composite Roller 50mm – Fiber compaction
• Utility knives, shears, high-temp gloves, lint-free wipes, acetone, masking tape

‌V. Material Estimate (Example: 2m×1m×0.3m mold)

• Epoxy Tooling Gelcoat: 2 kg
• Fiberglass (mat + fabric): 25–30 kg
• Epoxy Tooling Resin: 25 kg + Hardener 8 kg
• Vacuum consumables (flow mesh/bag film/tape): 8–10 m² per infusion

‌Notes

• All epoxy materials require vacuum drying (resin: 25°C×24h, fiberglass: 65°C×4h) to reduce moisture content.
• Mold cure cycle: 24h ambient + 4h post-cure @ 60°C.
• For RTM closed-mold processing: Requires injection ports, vents, clamping fixtures, and sealed steel mold halves instead of vacuum bagging.

TOOLS

I. Plug (Mother Mold) Machining Tools

Cutting / Rough Machining

• CNC Machining Center (foam/wood substitute rough milling)
• Handheld Engraving Machine (trimming, chamfering)
• Curve Saw / Jab Saw – rapid foam cutting
• Angle Grinder + Grinding Discs / Flap Discs – wood substitute rough finishing

Fine Finishing / Polishing

• Hand Plane, Scraper – wood substitute surface trimming
• Electric Random Orbital Polisher
• Sandpaper Set P80–P400 (dry sanding) & P600–P2000 (wet sanding)
• Wool Polishing Pad + Mirror-Finish Polishing Compound

Measuring / Inspection

• Digital Caliper 0–300 mm (±0.02 mm)
• Radius Gauge R2–R25 mm
• Surface Roughness Comparison Standards

II. Lamination / Resin Infusion Tools

Cutting / Lay-up

• Heavy-Duty Fabric Cutter (2 m width) or Electric Rotary Cutter
• Scissors (large shears + small angled snips)
• Marking Pen (vanishing ink)
• Laser Level – for baseline marking

Resin Mixing / Application

• Precision Electronic Scale 0.1 g resolution
• Electric Drill Mixer (≥ 1200 W) + Paddle Attachment
• Stainless Steel Rollers 50 mm & 75 mm (aluminum or toothed)
• Bristle Brushes 50 mm/100 mm (hog hair)
• Aluminum Spreader – uniform fabric consolidation

Vacuum / Infusion System

• Vacuum Pump 5 m³/h, ultimate vacuum –0.095 MPa
• Digital Vacuum Gauge (with data logging)
• PTFE Vacuum Tubing Ø 12 mm + Quick-Connect Fittings
• Resin Collection Vessel (transparent, 2 L, with filter)
• Resin Manifold (4-port)
• RTM Injection Gun

Auxiliary Fixtures

• Mobile Mold Turnover Stand (500 kg capacity, ±90° rotation)
• Metal Strips / Spring Clamps – mold alignment
• Heat Gun – local preheating and moisture removal

III. Curing / Post-Curing Tools

• Oven or Hot-Air Circulation Furnace (internal volume ≥ plug volume, max 120 °C)
• Thermocouples + Multi-channel Temperature Data Logger (± 1 °C)
• Infrared Thermometer Gun (spot-checking)

IV. Demolding / Trimming Tools

• Plastic Wedges – non-destructive demolding
• Rubber / Nylon Mallet – gentle separation
• Angle Grinder + Diamond Cutting Disc – cutting reinforcement ribs
• Straight-edge Cutter – straight trimming
• Pneumatic Edge Trimmer (3 mm cutter) – chamfering mold edges
• Dry Grinder + 5″ Sanding Pad P80–P400

V. Quality Inspection / Maintenance Tools

• Vernier Caliper (± 0.02 mm)
• Digital Height Gauge 0–300 mm
• Laser Tracker or Articulating Arm (3D scan vs. CAD, ≤ 0.1 mm)
• Barcol Hardness Tester – gelcoat hardness
• Holiday Detector (5–30 kV) – mold surface defect detection
• Wet Film Thickness Gauge 0–200 μm

VI. Personal Protection & Workshop Requirements

• Nitrile Gloves, Full-Face Respirator (A2-P3 cartridges), Safety Goggles
• Anti-static Coveralls, Slip-resistant Footwear
• Explosion-proof LED Lighting (24 V)
• Industrial Vacuum Cleaner (HEPA-level filtration) – fiberglass dust
• Explosion-proof Cabinet for Acetone / Cleaning Rags

Example of Tool Allocation (Single VARI Mold Production, 2 m²)

Notes:

• Clean all metal tools (scissors, rollers) with acetone before and after use to prevent cross-contamination.
• Calibrate the vacuum pump and oven every six months to ensure process repeatability.