How to make a plastic maquette

A maquette (a miniature sculpture representing a large final piece) needs to be made of the material that your final piece is going to be made of. This is because the material you choose, will respond in a certain way according to its nature and how you plan to treat it and manipulate it. An example might be if you were to cut out several shapes from a flat piece of polypropylene plastic then bend the sheet, the curve of the sheet would not be smooth due to remaining areas left after cut outs have been made, raising higher than the overall surface. If you were to do the same thing to a sheet of acrylic, there's a good chance it would snap.

Sometimes it is not always possible to use exactly the same material as your planned larger piece, so try and source the next closest thing to it. A thinner gauge (the thickness of the sheet of plastic) of the same material perhaps or at least a material that possesses very similar qualities to your planned final piece.

The next thing to consider is where your final piece is going to go. If your final piece is going outside, there are the effects of the elements upon your sculpture to consider. There will also be the human element to consider, i.e. health and safety. Are there sharp areas? are there moving parts? is it highly reflective and will this reduce vision from certain angles?

There is a chance some human interaction with your sculpture might involve them adding their own 'unique offerings' shall we say. Some plastics are easy to wipe clean and are very difficult to melt and are as durable as any metal if not more so. It is highly advisable to seek professional advice from plastics experts like plastics fabricators or manufacturer's when choosing the right plastic for your chosen environment. Be aware of the effects of heat on your sculpture over time, indoors or outdoors also.

Consider the colour of your final piece and that many plastics do not allow paint to adhere to their surfaces very well due to its non porous surface.

The reason for this is to reduce the element of surprise, unplanned compromise or worst of all, a complete failure with the much more expensive version of your sculpture, either financially or time wise.

Above you will see one of my maquettes. This was one of two made. Sometimes it's a good idea to make more than one version to test shape and idea. This one was made of foam as it was a cheap and easily attainable material. Once I was happy with the form, I had a version made of the same material the final piece would be made of. You will notice in the above image, the twist of the material on the right hand side. In creating the second maquette, I realised the plastic was not capable of making this twist so a compromise was made.

It may be that your planned final piece will be in several parts. During the maquette stage, a strong glue or a glue specifically designed for plastic such as 'Tensol 12' which contains dichloromethane methyl methacrylate may be needed. Tensol requires gloves, goggles and respiratory safety equipment to use, but it certainly does the trick and quickly! It is UK made and the makers number is; 01785 272727. It is possible to weld plastic when your large scale piece is to be made. A plastics fabricator can do this but if your large scale piece is lightweight enough and dependant on the planned location and environmental factors, it may be possible to use the Tensol in your final piece. Refer to manufacturer to confirm.

Cutting your plastic will require the nature of the plastic to be considered. If it is a brittle plastic, using pressure to cut it will cause it to shatter. More dense plastic can be cut with a jigsaw but the blade needs to be an acrylic blade. You can buy these in all good D.I.Y. stores. The blade itself is recognisable by the 'shark teeth' design that cuts both ways and not a blade with teeth that all go the same direction. Having tested it myself, any blade with teeth going all the same direction simply melts the plastic as it cuts through, and ends up a lump in front of the blade or even hardening around the blade. Not recommended! When using the jigsaw, remember not to force the blade through the plastic. If your maquette is particularly small and intricate, you may consider approaching a laser cutters who deals with plastic. They can either draw up your design on their C.A.D. system for you which will cost more or you can arrange that yourself and that way, once you have that design saved, you can have as many of the same design made as your finances allow!

The piece you see above is the finished article but the maquette was shaped in the same way as this. Each piece that was cut out then had to be sanded around the edges. The edges of your plastic will be rough after using a jigsaw, although a laser cutters finish will be far better and may not need refining. If you hand cut your plastic, sanding needs to start with a very rough sand paper (around 50-80 grit) you will see this number on the back of the sandpaper. Rub down the edges thoroughly and graduate to a slightly finer grit sandpaper (around 100) and repeat. Your aim is to increase the gradient of sandpaper until the surface of the plastic requires only 'T' cut to bring back its smooth surface

Once that part of the job is done, you may require the need to bend your plastic. You can heat this in your oven. Obviously, the thicker the plastic the longer your going to need to leave it in to soften. The above image of the tree was done by setting my oven to 200 degrees and putting in pieces that were 5mm thick in for around 10 minuets. Let this guide you to help gauge how long you should leave yours in for. The plastic sets very quickly (within 10ish seconds) once out of the heat so know what your plan is when you take it out to shape it an don't forget to use heat proof gloves!

You will see above a picture of my tester sheet. The bottom left corner of my plastic got bubbles in it. This was caused by a high concentration of heat, i.e. a blow torch. This was the beginning of the right hand section where the plastic began to bubble further then sink. The heat applied to your plastic needs to be even unless you are after this effect.

Perspex and acrylic are brittle and applying any pressure to it will make it crack or snap. If you heat it in the oven to shape it, once you take it out shape it quickly and completely to your requirements otherwise it will have to go back in to be re heated and if its been shaped round a certain amount, it will fold onto itself and stick onto another surface.

Place pieces in the oven with space between each part so as they don't stick to one another.

Put the pieces on a flat, clean, non stick baking tray.

There are some plastics that come with health warnings although it isn't used extensively. If you are not using a common plastic, it would be advisable to seek advice from plastics manufacturers or fabricators before heating it and also the proper way to dispose of it as some require specialist disposal.

I wish you luck in your creative venture! I hope this has helped you and please feel free to comment below. This has been my very first blog, I hope I did ok! :-)