Stretched Sprue
Making aerials and bolts from left over sprues
How to make aerials, scale wire and even bolts from left over plastic sprues
The plastic sprues left over at the end of a plastic model kit can be a valuable resource and one of the things that can be done with it is to form it into very thin strands. These strands make good scale wire, aerials and can even be formed into bolts.
Method
1. You will need a small heat source and a 'tea light' or 'night light' candle is ideal for this.
2. Hold a straight piece of sprue a few centimeters over the heat source rotating it so that it is heated evenly. Hold the sprue in two places on either side of the heat source.
3. After a few seconds, the sprue will begin to soften. This can be seen because the plastic becomes shiny.
4. Lift the spue away from the heat source and at the same time gently pull the two ends to stretch the sprue into a long length.
Technique and Results
The results that you get will depend on a number of factors such as how soft the sprue has become before it is pulled, how thick the sprue is and how fast and evenly the two ends are pulled apart. Kit makers use slightly different types of styrene plastic with some tending to be soft and others tending to be brittle and this will also affect the success of stretching sprue.
With practice you will be able to get long strands that are ideal for scale wire or the aerial wire on aircraft. These strands can sometimes be thinner that human hair. By pulling one end you may get a strand that starts off thick and gets progressively thinner which may be good for AFV aerials.
Do not be put off if the method fails a few times. Many times you may end up with the strand breaking, or the plastic becoming too hard before it has been pulled very far. However, keep trying because it costs nothing and with persistance you will eventually get the technique.
Making Scale Bolt Heads
Start off by making a length of stretched sprue that is not too thin (about the thickness of human hair is good). Then hold the end of the stretched sprue up to the heat source. It will melt and flatten out into a mushroom shape. Take this away from the heat and when it has cooled cut it off to use as a round scale bolt head.
~~ Last updated May 9, 2009 by Peter Hall. ~~