Lesson 1Resin additives and modifiers: thickeners, accelerators/inhibitors, UV stabilizers, flexibilizers, fire retardants and fillersThis section details how thickeners, accelerators, inhibitors, UV stabilisers, flexibilisers, fire retardants, and fillers modify polyester and vinyl ester resins, affecting viscosity, cure profile, durability, and processing safety for reliable results.
Thickeners for sag control and vertical surfacesAccelerators and inhibitors for cure timingUV stabilizers for long‑term color retentionFlexibilizers for impact and crack resistanceFire retardant additives and smoke performanceLesson 2Common release agents: semi-permanent release films, PVA, waxes; selection criteria and interaction with gelcoat and mold surfacesThis section reviews waxes, PVA, and semi-permanent release systems, explaining selection based on mould material, cycle count, and gelcoat type, plus correct application, buffing, and troubleshooting of sticking or print-through issues in everyday workshop use.
Paste wax selection and buffing techniquePVA films: spray parameters and cleanupSemi‑permanent releases for high cyclesInteraction with gelcoat and mold surfacesDiagnosing and fixing release failuresLesson 3Gelcoat selection: types, weather-resistant gelcoats, pigmentation and compatibility with polyester laminatesThis section covers gelcoat types for exterior use, including ISO and vinyl ester gelcoats, weather-resistant and marine grades, pigmentation systems, thickness control, and compatibility with underlying polyester or vinyl ester laminates for long-lasting finishes.
ISO vs vinyl ester gelcoat selectionUV‑stable and marine‑grade gelcoatsPigments, color matching and hiding powerRecommended gelcoat film thickness rangeAvoiding defects and adhesion problemsLesson 4Material sourcing and specification: reading datasheets, selecting supplier specifications and typical commercial part numbers to search forThis section teaches how to read resin, gelcoat, and fabric datasheets, interpret key properties and certifications, compare supplier specifications, and identify typical commercial designations and part numbers for reliable sourcing from local or regional suppliers.
Key resin and gelcoat datasheet propertiesReinforcement fabric styles and codesComparing supplier specs and tolerancesCertifications, standards and approvalsTypical commercial grades and part numbersLesson 5Catalyst chemistry and dosing: MEKP types, concentration guidelines, temperature effects and pot life implicationsThis section covers MEKP catalyst chemistry, common activity grades, safe handling, and dosing rules, explaining how temperature, resin mass, and promoter levels influence gel time, pot life, cure completeness, and laminate quality in hot workshop conditions.
MEKP composition and activity differencesStandard catalyst percentage ranges by resinTemperature effects on gel time and exothermAdjusting pot life for part size and processSafe handling, storage and mixing practicesLesson 6Polyester resin varieties: orthophthalic vs isophthalic vs vinyl ester for outdoor use, weathering and chemical resistanceThis section compares orthophthalic, isophthalic, and vinyl ester resins for outdoor service, highlighting differences in water uptake, chemical resistance, toughness, cost, and when to upgrade systems for demanding exterior structural elements in tough weather.
Orthophthalic resins: pros, cons and usesIsophthalic resins for improved durabilityVinyl ester for high corrosion resistanceWater absorption and osmotic blisteringCost versus performance trade‑off choicesLesson 7Fiber weights and areal density selection: typical g/m2 ranges for cornice applications and impact on stiffness and weightThis section explains how fabric areal weight and stacking sequence influence stiffness, impact resistance, print-through, and handling, with typical g/m² ranges and layup strategies for cornices and similar exterior architectural parts in our climate.
Common g/m² ranges for cornice laminatesBalancing stiffness, weight and costLayer stacking to control print‑throughLocal reinforcement in high‑stress areasHandling and wet‑out of heavy fabricsLesson 8Environmental degradation mechanisms: UV, moisture, thermal cycling and how materials mitigate these effectsThis section explains how UV, moisture, oxygen, and thermal cycling degrade exterior fiberglass, including chalking, yellowing, blistering, and microcracking, and how gelcoats, stabilisers, and resin selection mitigate these mechanisms under harsh African sun and rains.
UV‑induced yellowing, chalking and embrittlementMoisture ingress, blistering and hydrolysisThermal cycling, fatigue and microcrackingRole of gelcoat and topcoats in protectionMaterial selection for harsh outdoor climatesLesson 9Types of fiberglass reinforcement: chopped strand mat, woven roving, biaxial/triaxial fabrics, stitched fabrics and directional fabricsThis section compares chopped strand mat, woven roving, biaxial and triaxial fabrics, stitched multiaxials, and directional reinforcements, focusing on drapability, print-through, mechanical performance, and suitability for exterior structural shapes in local builds.
Chopped strand mat: uses and limitationsWoven roving for thickness and strengthBiaxial and triaxial fabrics for stiffnessStitched multiaxials vs traditional weavesDirectional layups for load‑bearing zones
