Guide: laminating with acrylic resin (making a support shell)

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Laminating with acrylic resin (making a support shell)

With this guide you learn to laminate with acrylic resin and triaxial fibreglass cloth. The technique is ideal for making a strong, lightweight support shell for a silicone mould, or for reinforcing an acrylic resin cast. You work wet on wet for the best adhesion.

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What are you going to make?

You build up a strong acrylic resin laminate layer by layer with triaxial fibreglass cloth and chopped fibreglass as reinforcement. The result is a sturdy support shell or a reinforced acrylic resin cast. Because acrylic resin adheres best when you work wet on wet, you apply each new layer before the previous one has cured.

💡 Working wet on wet means the previous layer is not yet cured (wet) before you apply the next layer. So work promptly, one after another.

Required materials

🛒 From the webshop

🧰 Supply yourself

  • Mixing cup(s)
  • Mixing spatula
  • Scale
  • Scissors
  • Acrylic resin colorant (optional)
  • Mould or model to coat

Processing data

PropertyValue
Mixing ratio acrylic resinA : B = 1 : 2 (1 part liquid, 2 parts powder)
Example mix50 grams liquid + 100 grams powder = 150 grams
Thix A thickener2% by weight
Chopped fibreglass in filler resinaround 5% by weight
First resin layer thicknessat least 1 mm
Methodwet on wet

Preparation

Lay out everything before you start so you can work wet on wet, one after another. Clean the mould or model well and place it firmly on a flat surface.

Pre-cut strips of triaxial fibreglass cloth to the size of the mould so you can press them straight into the fresh resin.

⚠️ Acrylic resin has a limited working time. Mix an amount per layer that you can process within that time, and clean the brush and mixing cup with water in between before the resin cures.

Lay out the materials

Lay out all materials: acrylic resin set, triaxial fibreglass cloth, chopped fibreglass, Thix A, mixing cup, spatula, scale, wide brush and scissors. The mould is cleaned and ready to be coated.

Fig. 1 – Lay out all materials.
Fig. 1 – Lay out all materials.

Mix the acrylic resin

Pour an amount of acrylic resin liquid (A component) into the mixing cup and add twice as much acrylic resin powder (B component). In this example 50 grams liquid and 100 grams powder.

Mix the 150 grams of acrylic resin well into an even paste.

Fig. 2 – 50 grams acrylic resin liquid with 100 grams acrylic resin powder.
Fig. 2 – 50 grams acrylic resin liquid with 100 grams acrylic resin powder.

Add thickener and optional colorant

Add 2% Thix A to the mixture (so 3 grams for 150 grams). Mix the Thix A in well so the resin becomes evenly thick.

Add acrylic resin colorant if desired. This is the color that will be visible later.

Fig. 3 – The total mixture including colorant and thickener.
Fig. 3 – The total mixture including colorant and thickener.

Apply the first resin layer

Take a wide brush and coat the mould completely with the paste. Go carefully along the edges and corners and make sure the whole surface is covered with at least 1 mm of resin.

⚠️ On a mould with fine or many small details, it is important to dab or stipple well with the brush so the air is pushed out of the mould.
Fig. 4 – The first layer is applied with a brush.
Fig. 4 – The first layer is applied with a brush.

Lay in the first layer of cloth

Cut a strip of triaxial fibreglass cloth to the size of the mould and press it gently into the resin. Make sure you do not push the cloth all the way through the resin.

Fig. 5 – A first strip of triaxial fibreglass cloth is gently pressed into the resin.
Fig. 5 – A first strip of triaxial fibreglass cloth is gently pressed into the resin.

Cover the cloth with resin

Apply the remaining resin into the mould until the cloth is fully covered.

Fig. 6 – The rest of the mixture is applied onto the triaxial cloth.
Fig. 6 – The rest of the mixture is applied onto the triaxial cloth.

Clean tools in between

Clean the brush and mixing cup under the tap in between so they are ready for the next layer. As long as the resin has not cured, the material is easy to clean with water.

Fig. 7 – Material is easy to clean with water as long as the resin has not cured.
Fig. 7 – Material is easy to clean with water as long as the resin has not cured.

Mix filler resin with chopped fibreglass

Mix another amount of resin including thickener; colorant is no longer needed. Add around 5% chopped fibreglass by weight to the mixture and mix until a nice smooth mass forms.

Fig. 8 – Chopped fibreglass is added to the acrylic resin mixture.
Fig. 8 – Chopped fibreglass is added to the acrylic resin mixture.

Apply the filler resin

Apply the fibreglass-filled resin onto the still-fresh previous layer and spread it well with the brush.

⚠️ Make sure the resin and fibre are pressed well into the corners.
Fig. 9 – The mixture of resin with chopped fibreglass is applied onto the still-fresh acrylic layer.
Fig. 9 – The mixture of resin with chopped fibreglass is applied onto the still-fresh acrylic layer.

Second strip of cloth

Cut another strip of triaxial fibreglass cloth to the size of the mould and press it into the freshly applied acrylic resin layer.

Fig. 10 – A second strip of triaxial fibreglass cloth is applied.
Fig. 10 – A second strip of triaxial fibreglass cloth is applied.

Apply the final resin layer

Mix another batch of acrylic resin and thickener. Apply it with the brush onto the previous, still-fresh acrylic layer and smooth it.

Fig. 11 – The final resin layer is applied.
Fig. 11 – The final resin layer is applied.

Result

Let the laminate cure fully. You now have a strong, lightweight support shell or reinforced acrylic resin cast.

Fig. 12 – The mould together with the cast in acrylic resin.
Fig. 12 – The mould together with the cast in acrylic resin.

Additional information

  • Always work wet on wet: apply each new layer before the previous one has cured, for the best adhesion.
  • Acrylic resin adheres very well to itself, even when an earlier layer has fully cured.
  • With a lot of detail in the mould, dab or stipple well with the brush to drive out air.
  • Clean tools with water as long as the resin has not cured.
  • This technique is suitable both as a support shell for silicone moulds and for reinforcing an acrylic resin cast.

Storage

Store the acrylic resin liquid and powder and the Thix A well sealed, dry and at room temperature so the processing properties are preserved.

Frequently asked questions

What is the mixing ratio of acrylic resin?

Two parts powder to one part liquid by weight, for example 100 grams powder to 50 grams liquid. Then add 2% Thix A as thickener.

Why both triaxial cloth and chopped fibreglass?

The triaxial fibreglass cloth gives strength in multiple directions, the chopped fibreglass fills intermediate layers and corners and makes the laminate compact and strong.

Why work wet on wet?

By applying a new layer before the previous one has cured, the layers bond optimally into one whole and no weak separation forms between the layers.

Can I use this as a support shell for a silicone mould?

Yes, that is one of the main applications. The support shell holds a flexible silicone mould in shape during casting.

No rights can be derived from this description. Read the safety instructions before use.

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V120215.1 | Updated June 2026

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