MODEL MAKING SESSION 1- This first session of model making was focused on plastics/Acrylic. Acrylic is strong, lightweight and transparent. It can be used as a replacement for glass, can be coloured, textured and it is a very simple and easy material to work with. This was what we were working with during this session.
CUTTING ACRYLIC
To start off with we needed to cut our piece of Acrylic into three sections, this then led us onto using the Ban saw (please be aware of Health & Safety when using these machines). With Acrylic you need to use a specific blade used for plastics only, the sheet of Acrylic must be held firmly and fed into the machine slowly, by taking your time it helps prevent any defects to the Acrylic. Because we are using a Ban saw and they have a thin blade it is not suitable for cutting curves as this can snap the blade and cause a safety risk.
Slowly apply pressure to the Acrylic as you feed it through the machine, because after cutting the Acrylic will appear rough, and have the small lines from where the blade has sawed through, this is when you need to file the Acrylic down so it appears smooth and has a professional appearance.
SANDING ACRYLIC
Sanding the Acrylic down to become smooth can take a little while. Depending on the grade of sandpaper the appearance can vary, by using a fine grade paper the outcome will appear smoother, you will need to sand the Acrylic for a short while until it is smooth and the saw lines have disappeared. Some scratches may be deeper than others which means you’ll have to use the sander machine to help even out the surface before sanding the saw lines. A very good way of getting a smooth finish is by using wet-or-dry sandpaper, this has a very fine grit and helps create a smoother outcome. Now it was time to polish the edges of our Acrylic which would allow for all the sanding marks to become less apparent.
By using an electric polisher/buffer it gives the edges a satin look, to do this you need to apply some wax to the polishing wheel, then slowly press your edges into the wheel and cover the whole area. If you have not sanded the edges enough you will notice that the higher saw marks will appear more after polishing, to fix this just re sand the edge and then repeat the polishing process. Once you have polished every edge with the wax it will then need to be buffered, this will remove the wax and leave the edges smooth and silky. This process is the last stage in getting your Acrylic looking professional and can be used in a design project.
FORMING ACRYLIC WITH A STRIP HEATER
Using a Strip heater is useful for is you want to manipulate your Acrylic, these allow you to form a straight-line bend. Because they only heat the area you choose this allows for you to form it at specific angles, this is useful for if you are given a concept which only uses 90 degree angles.
This is not a difficult machine to use however, it can be difficult to get correct angles, to prevent this from happening you can use something called a forming jig. Forming jigs can be set to a specific angle which you then press your heated Acrylic against, this allows for precision and helps the final outcome be more accurate. When it came to myself heating my Acrylic I did not work to any angles, this meant once my Acrylic was heated enough to bend I could manipulate it in any way I chose to.
When heating up your Acrylic you need to keep an eye on it, if you leave it you are creating the risk of either discolouring the Acrylic, this will then not be able to be used if you were wanting it for a design. Another risk is melting the Acrylic, this can then lead to it getting inside the Strip heater which can cause damage to the machine.
DRILLING ACRYLIC
Once we had done all of the previous stages it was time to drill the Acrylic. When drilling this material we used a hand drill, this meant we needed to be accurate and have a steady hand otherwise it would not be accurate. Because once the hole had been drilled it created rough edges from where it had entered and left the Acrylic, this then needed to carefully either be sanded off, or we could just gently peel off the excess waste.
Now we have our Acrylic all ready to be used for our model it was the end of the session, because we are having several sessions focusing on different materials, which we will then bring all together in a final model. This will incorporate all these small experiments with the different materials which we have created within these sessions.
Peta-Louise Krog 
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