Category: Mould Making

Caterpillar to Butterfly – From mould to beautiful pots

We love custom projects and seeing collaborative design ideas transform from initial sketches to a beautiful final product and the 1200 custom bowls for Robina Town Centre, Gold Coast, was no exception.

When asked to add offset line detail to one of our classic pot shapes we leapt at the challenge.

Mould-making requires literal out of the box thinking whereby we approach pot manufacture from the outside in. This blog shares the creative journey from pot design to installation to give you a sneak-peak of what some of our custom pot manufacturing steps entail.

We are also proud to hand-manufacture to order right here in Australia.

Design to Mould

The final design is transformed into a plug (pattern) which forms the internal shape of the mould.

Silicone is applied and a fibreglass shell follows.

The mould is now ready for our GRC (Glass-fibre reinforced concrete) production process.

Final Touches and Delivery

Once the pots have cured they move to our detailing department to ensure that each pot complies to our stringent quality control procedures before they are wrapped and prepared for delivery.

The completed pots look great once installed and compliment the interior styling theme.

We had a lot of fun with this custom design project and look forward to sharing more of our designs and projects with you in future.

For any custom design and manufacturing queries contact our office on 02 6672 1190 or send an email to, we’d be delighted to assist with your next project.

Quatro Design – where landscape meets architecture

the art of mould making final stage

The mould is now lined / trowelled with glassfibre cement [GRC] 12-15mm thick to create a smooth, glassy finish, then cleaned of any loose threads, and left to set for 24 hours. Once set, the crane is used to pull the finished product from the mould and detailed.

We now have 3 parts of the tree ring clamped together, the seams will be bolted and potentially filled with a gasket [dependent on end environment].

See our facebook page for the full gallery of images.

relief for designer planters

We are currently working on a project for the Fraser Coast Council which sees our planters with a low relief (bas-relief) design on one side of each planter. This is acheived by placing a reverse relief inside the planter mould then casting in glass fibre reinforced concrete (GRC). To ensure the relief design remains crisp and intact, a rubber film is placed over the mould which when almost dry is peeled away to expose the artwork.

the art of mould making part 2

The wooden frame is now coated in fibreglass and sanded to create the plug which in turn makes the finished mould, this process will take approximately 3-4 days. This is a third of the overall tree ring so it’s no small task.

the art of mould making part 3

Now that the plug is complete we begin to cover the plug in a fibreglass shell [the red ends in the first image are the beginnings of the mould]. Once the new fibreglass top/shell is completed a frame is built around the mould so it can be inverted, then the plug can be removed from the mould using the crane.

During this process the plug will usually end up slightly damaged, but now if we ever have to make another plug we can do so by working back from the mould.

Stay tuned for the final stage and where will join together the 3 pieces which will make the complete tree ring.

Manufacturing with GRC (Part 2) Making the plug

Making moulds is fundamental to our operation as a manufacturer of GRC products.  And over the years we’ve got pretty good at it.  In this blog we feature the first step in making a new fibreglass mould for a new seat shape in our POD range of street furniture.  That first step is the plug. 

Dave (who wishes to remain anonymous) is one of our three mould-makers, and he started on making the plug a week or so ago.  The plug is the exact shape of the end product, and it is from the plug that he will make the fibreglass mould.  We typically build the plug from timber materials or from CNC-cut high density foam. 

Once the basic shape of the plug is made, the next step is to apply high-build coatings that are then hand-sanded and polished to a high gloss finish.  This is the long and laborious step.  The fibreglass mould surface will reflect the surface of the plug so it’s important the mould-maker (i.e. Dave) gets this step right. 

Dave has photo-documented each step in the process starting with the timber materials, making the plug which in turn makes the mould for the newest member of our POD street furniture range, Bulb.  Next week he will move on to step two – taking the fibreglass mould off of the plug.  

the art of mould making

Today at Quatro we are making a mould for a 4m dia tree ring with bench seat and thought we’d like to share some photos of the process involved in making something that in theory seems so simple.

The timber frames used to make the mould are one of the most time consuming processes in the overall construction of the product, using tecninques heralding back to old barrel making or clinker boat building. The mould is painstaking built in timber first, screwed & glued, [the stage that you see here] then the thousands of screws used to build something of this size are taken out and the holes bogged & filled. Overall this first stage of the mould making process will take approximately a week. This old fashioned technique is favoured by us for various reasons but another way of producing a mould like this would be cutting a CNC 3D mould in foam. A dying art? Stay tuned for the next stage!

Manufacturing with GRC (Part 3) Laying up the firbreglass mould

In the previous blog, we followed Dave in building the plug from which the fibreglass mould is made.  Now that he has built the plug and polished the surface to a high gloss finish, he’s ready for the next stage – laying up the fibreglass to form the mould on the plug.   


To begin he spray-applied a gelcoat layer on to the plug surface.  As soon as this has cured/hardened sufficiently, he begins applying layers of fibreglass chopped strand matt and wetting it out with polyester resin.  This hardens and forms a fibreglass shell – the negative shape of the plug.

The mould for this project is a two-part mould.  Dave lays up the main body of the mould, and then turns the plug over and then lays up the second part which forms the lid section.


Once both mould parts are completed, the plug is separated from the mould.  Here we see Dave sitting on the plug next to the mould.  Nice work, Dave!

Manufacturing with GRC (Part 1) Design & Development

At Quatro Design we design and develop a wide range of our own products. Sometimes an idea or design concept can inspire us to develop an entire product range based on the original concept.


A good example of this is our SOUL range based on the timeless design of the terracotta flowerpot.  Our new Delta seat planters were inspired by the design of a coffee table seen at Harrods in London. 


We are a solutions-based manufacturer, and in addition to developing our own products, we also work collaboratively with architects and designers to design and deliver products that meet their specific design requirements.


Moulds are at the heart of what we do. Mould fabrication can be expensive and we are always mindful of this. We are always looking for creative ways to keep our mould costs as low as possible. Where possible we strive to ensuring a mound has multiple uses.  Oftentimes we’re able to adapt and reuse moulds on other jobs. This helps to keeps to reduce mould costs and consequently the cost of products.  


Our design team understands GRC. We design to ensure that a product is buildable and will deliver the best possible outcome for our clients. At Quatro Design we love challenges and we’re always inspired by new designs that push the boundaries of GRC manufacture for landscape and streetscape-related products.  In recent times we’re seeing an increase in inquiries for custom balustrade planters and green wall façade planters.

Manufacturing in GRC (Part 4) Spray Lay-up

So we’ve looked at the mould-making process. Now we move on to making products in GRC.

GRC stands for glassfibre reinforced concrete which means it is a composite material made up primarily of sand and cement plus glassfibres for structural reinforcement. At Quatro Design we use equipment specifically designed for GRC manufacture. The first piece of equipment is a shear mixer which mixes fine sand, cement, water and additives at high speed. This results in a render with a consistency a bit like soft-serve ice cream. This render mix is then transferred into the GRC spray pump which then pumps the render to a spray gun that incorporates a fibreglass roving chopper. The spray gun does two things at the same time – it atomises the render and chops the fibreglass roving into strands around 25-35mm long. It then simultaneously shoots both the render and the chopped fibres at the mould causing them to mix together as they exit the gun.

In the video here you can see a bowl being laid up in GRC. See how Anthony moves the gun around the mould applying an even layer of render mixed with glassfibres. When he’s finished spraying, the GRC will be hand-compacted using special rollers. With this bowl, a rim will be laid up separately in a matching rim mould and later joined on to the bowl mould. The next morning the completed bowl will be lifted out of the mould ready for detailing.