Fibreglass fabric supplies reinforcement; epoxy transfers load into the fibres and protects them. The goal is complete wet-out with the fibres lying in the intended orientation and no trapped air, wrinkles or pools of excess resin.
A wet laminate is not automatically a good laminate. Too much resin adds weight and can allow fabric to float. Too little leaves pale or silver-looking dry fibres. Work methodically from the centre toward open edges and plan overlaps before mixing.
Quick answer
Prepare the substrate, cut and dry-fit every ply, mix manageable batches, wet the surface, place the fabric without stretching it, work resin through until the weave turns uniformly transparent, then remove air and excess resin without starving the cloth.
What you need to know
- Orient fibres to match the repair design.
- Round sharp outside corners and fill tight inside corners so fabric can lie down.
- Stagger ply edges rather than stacking every edge in one line.
- Use peel ply only when it suits the next process and remove it after cure.
Tools and materials
- Specified woven cloth, biaxial fabric or tape
- Compatible epoxy resin and hardener
- Sharp dedicated shears
- Mixing and dispensing tools
- Brushes, spreaders and laminating roller
- Peel ply if specified
- Masking, release film and PPE
Step-by-step method
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Prepare the substrate
Make the area sound, clean, dry and abraded. Shape bevels and radii to the repair specification. Remove dust and protect adjacent surfaces.
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Cut and sequence the plies
Use templates where useful. Mark orientation outside the bond area and stack plies in application order. Dry-fit around corners and transitions.
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Mix a controlled batch
Use the exact ratio and choose a batch size that can be placed within working time. Pour mixed epoxy into a roller tray or broad container when that is allowed to slow heat build-up.
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Wet the surface
Apply a thin even coat to the prepared substrate. Porous areas may need extra attention, but avoid leaving deep pools.
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Place the fabric
Lay the cloth onto the wet surface and smooth it gently. Avoid pulling the weave out of alignment. Work from a stable reference point toward the edges.
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Wet out completely
Add resin in small amounts and use a spreader or roller to move it through the fibres. Properly wet fabric becomes uniformly translucent; pale or silvery areas need attention.
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Consolidate and cure
Roll trapped air toward an edge and remove surplus resin. Apply subsequent plies within the system’s timing. Inspect for lifted edges and bubbles before leaving the laminate to cure.
Watch the demonstration
The video is supporting material. Follow the current product instructions and safety data sheet for the products in your shop.
Common mistakes
- Cutting reinforcement after mixing
- Trying to force heavy cloth around a sharp corner
- Flooding the laminate with resin
- Using excessive roller pressure and starving the fibres
- Leaving trapped air at overlaps
- Sanding exposed structural fibres during finishing
Safety
Read the current resin, hardener and filler labels, technical data sheets and safety data sheets before opening the containers.
Wear splash-resistant eye protection and chemical-resistant gloves selected for the product. Keep epoxy off your skin; repeated exposure can lead to sensitization.
Provide ventilation appropriate to the job and product. Sand only fully cured material, control dust at the tool and wear suitable respiratory protection where the risk assessment requires it.
Mix only the quantity you can apply within the stated working time. Epoxy cures faster and produces more heat when left in a deep mixing pot.
Frequently asked questions
How can I tell when cloth is wet out?
The fibres change from white to uniformly translucent with no silvery dry patches. The laminate should not be floating in a deep resin layer.
Should resin go down before the cloth?
A thin wet-out coat helps contact, especially on porous substrates. Some controlled processes wet the cloth separately. Follow the repair procedure.
Why does fabric lift at corners?
The radius may be too tight, the fabric may be too stiff, or trapped air and spring-back may be present. Improve the radius, use an appropriate fabric or hold-down method.
Can I apply several layers at once?
Often yes within the allowed working time and laminate schedule, but heat, access and consolidation become harder as thickness increases.
Get the right materials for the job
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This guide provides general educational information. Products, substrates and working conditions vary. Follow the current technical data sheet, package directions and safety data sheet for every material you use. Structural, code-regulated or safety-critical work may require a qualified professional.