So the first thing to do was take a cast of the front armour to use as a base. Included in this cast is the flange round the outside, as this is important to have when making stuff in fibreglass. not only does it strengthen the mould, but also allows you to work up to and past the edge of what will be the finished part, making sure there are no thin or weak spots right on the edge. Obviously this means more clean up work in the long run, but the finished product it much stronger.Next its time to add the tank section. this was a fibreglass cast took off a bit of soil pipe, then heated and bent to the right curve. To get the side bits took a bit or searching for a tube just the right shape, but in the end I found an old water pistol detachable tank, which was just the right shape. A mould was taken of that, then a cast made, and it cut up and stuck into place each side. It was then just the long boring job of adding and sanding filler, till the profile was right.
With the tank on the back the right shape from all angles the grill section needed to be added. Now making these slots on the finished piece would prove quite a problem, so we cheat and make them separate, then stick them in place.A small slab of polyurethane resin was cast, and then put on the milling machine to get the surface flat. It was then marked out, and the grooves milled into the surface. This makes sure they all match and are the same length and width. The finished item is then milled so there is a slight gap round all the grooves, and put in the oven for five minutes to heat up. Once hot polyurethane resin goes soft and pliable, and can be reshaped, then once cool holds it new shape.So the grill section was heated up then held against the outside of the tank where it was to go till cool. It was then just a simple case of cutting a neat hole, inserting it in place, then filling and sanding round the edges.
Now the back is finished you can compare it to the first pictures and see the difference. The main one is the bottom edge is now rounded and not concave, and the neck is flatter along the bottom than the front.Unlike ABS this back is all in one, oppose to the tank separate that has to be fixed on. The main reason is ABS starts out as a flat sheet, and is formed by heating and vac forming over a master mould. ABS stretches quite a lot, but it would never form the all in one back armour as there are too many angles and curves to work with. Another plus side to fibreglass as itís a liquid to start with; no shape is to complex to make. The moulds get quite complex, but the casting is easy.Personally I like the fixed on look over the two separate parts but itís really personnel choice. Some die hard troopers say the two part is more film accurate, but there's picky and picky. As long as the suit of armour is a good likeness to the film used one, I think itís more about having fun on days out trooping, than picking holes in other peoples armour.
Making the back of the torso armour was made a lot easier as all the hard work getting the front section symmetrical could now be used as a base for the back.Saying that, there is still a significant amount different between the front and the back but you have to start somewhere.