The developing steps for a Fiberglass Project to become reality.

Most people have heard about fiberglass products and maybe even have researched enough to know that fiberglass can provide weight reduction over other products like metals, concrete and even wooden products, but they don't understand the process required to get their project produced. Below we will try to explain the basic steps required from start to finish with a fiberglass product.

Click on the to expand the section for more detailed steps that your fiberglass project may encounter during the planning and production process.

Fiberglass Project Review and Production Planning Process

• Review the Fiberglass Project
  • Is the current design moldable for fiberglass processes?
    • Size - The size of the finished part is discussed
    • Draft Angles - 3° or greater is preferred
    • Radii - Sharp corners can hinder manufacturability
    • Wall Thickness - The thickness of the finished part is determined
    • Die locks - Does your part contain features that will require multi-piece molds?
  • What type of finish is required?
    • Uncoated exposed resin/ glass molded surface
    • Sandable gelcoat surface for customer painting
    • Finished gelcoat industrial quality
    • Finished gelcoat Class A automotive finish
    • Post-molded painted finish
  • Resin and Fiberglass Matrix or Schedule?
    • Determine the type of resin required for project
      • General Purpose
      • Chemical Resistance
      • Fire Retardant
      • Heat Stability
      • Impact Resistance
      • UV Stability
    • Determine the fiberglass requirements
      • Glass to resin Ratio (usually 30% glass : 70% resin)
      • Fiber weave - chop strand, woven mat and bi-directional mat
      • Fiber makeup - Standard E glass, arymid fiber, carbon fiber
    • Finished gelcoat industrial quality
    • Finished gelcoat Class A automotive finish
    • Post-molded painted finish
  • Secondary Fiberglass Molding Processes
    • Inserts and reinforcements
      • Stiffening Materials - Core mats, foam cores, balsa cores, ridged wooden cores, metal plates, engineered extrusions
      • Brackets - Hinges, threaded inserts, latches, mounts, bumpers
  • "B" Surface Finish Requirements
    • Rough open glass/ resin surface (burr free)
    • Pigmented Resin
    • Hot Coated Fiberglass
    • Smooth Smooth Finish (Requires RTM Process)
• Production Fiberglass Molding Determination
  • "B" Surface Finish
    • Rough Backside
      • One-off fabricated part
      • Open molded fiberglass part, typical volume 250 part per year per mold
    • Smooth Backside
      • RTM Lite (light weight composite molds) typical volume 2000 parts per year per mold
      • Conventional RTM (machine matched metal molds) typical volume 2750 parts per year per mold
      • CCBM molding (smooth but porous surface machined metal molds) typical volume 6000 parts per year per mold
      • Cold Molded (smooth but porous surface machined metal molds) typical volume 6000 part per year per mold
      • SMC - typical volume 12000 parts per year per mold
  • Part Geometry
    • No die locks single cavity mold works with any above listed molding method
    • Die Locked
    • Open molded with parting flanges
    • CCBM with minor die locks
    • Other molding methods but may require experimenting and more costs
• Temporary Fiberglass Pattern Process
  • Conversion of existing part
    • Part must be rigidized
    • Demolding flanges added
    • New alternatives
  • Creation of pattern from CAD Model
    • Shrink is added to CAD model
    • Run out and flanges added to the model as needed
  • Finishing Temporary Pattern
    • Sealed with polyester based primer
    • Top coated and surface detailed to finish requirements
    • Release agents are applied
• Production Mold Building Process for Composite Molds
  • Open Molded Fiberglass Products
    • Tooling gel coat applied over prepped pattern
    • Backup gel coat is applied
    • 1 layer hand laid chop strand mat applied
    • 2 additional layers of non-shrink chop applied allowing curing between layers
    • Reinforcements attached and encapsulated
    • Outer surface sealed with hot coat and labeled with identifying numbers
    • Demold from temporary pattern
    • Build first article part or FRP master if additional molds are required
  • Close Molding (RTM lite, CCBM)
    • Tooling gel coat applied over prepped pattern
    • Backup gel coat applied
    • One layer chopped strand fiberglass mat applied
    • Two additional layers of non-shrink chop applied (allowing curing between layers)
    • Reinforcements attached and encapsulated
    • Outer surface sealed with hot coat and labeled with identifying number
    • Demold from temporary pattern
    • Apply pre engineered sheet wax to mold cavity to simulate finished part thinkness
    • Build in the sheet wax channels for vacuum seals and resin pathways
    • Mount infection ports and vacuum ports
    • Counter Mold Production
      • RTM Lite - Gelcoat engineered wax simulation
      • Hand layup one layer of chopstrand fiberglass mat
      • Build up chop and reinforce as needed
      • CCBM - coat engineered wax with silicone material
• Production Fiberglass Parts
  • First Part Approval
  • Build any required Fixturing
    • CNC Fiberglass Part Trimming
    • Construct Router Nest for Part
    • Setup Program for CNC Router
    • Hand Trimming
    • Hand Router Guide
    • Scribe Production Fixture
    • Gring Off Flanges
  • Final Inspection and Shipping

Arrowhead Plastic Engineering, Inc. provides this information as a very basic guideline for the steps that you will need to get your fiberglass product design from the design phase to the final product. Each project may present specialized situation and product development that are not listed above.