As usual I decided to build my model to studio-size, this is because I'm building the other Captain Scarlet vehicles at that scale and it allows me to use some of the same parts that were used on the original, which is always a big time saver. I figured the size to be 22 inches long, the telltale measurements come from the toy wheels on the rear and the fact that the Spectrum roundel's are 1&1/2 inch wide.

The Build .. by David Sisson

My usual approach to building models is to start by drawing up a blueprint and then create a master pattern. On the left is the start of my first SPV model, built back in the late 1980s, formed by assembling layers of Balsa wood. However on this model I ended up using a different approach.

Scratchbuilding consists of two basic problems, firstly actually being able to physically produce all the parts and then of course making sure that these parts are actually as accurate as possible. People often seem to fail in one department, with the model either being well built but inaccurate, or looking accurate but made poorly from sub-standard materials; if they are really unlucky they will fail in both areas! The construction challenge is usually so large that mistakes are bound to happen, compromises occur and you end up with a model that you refer to as 'version 1' and then have to start again and build a revised second model, and sometimes more.

The SPV is a series of curves on curves, that make it one of the more complex craft to recreate. While I've seen many replicas over the years I have never really seen a true copy of it and I feared that I too would end up with a replica that failed to live up to my high expectations.
The model was already going to take me a long time to build and the idea that I would then have to build another to fix the faults was off-putting. The big problem is that you are starting from zero and it's not until you have the final 3-dimensional object in front of your eyes that you can tell if it's correct. So what if you start with another model to begin with?

As I began this project I was given another SPV replica to complete. The model had been built by a friend, Kevin Pedley, and had been sold as an unfinished project. My job was simply to add missing details, including an interior, and then paint.
Overall the model looked very good and the engineering work in the chassis was brilliant. However while I thought some areas were very good there were others that I wasn't happy with at all, partly due to the fact that the model was undersized for my requirements. I remember thinking if only I could move the parts around it could be brilliant, so I started to make a list of changes that I would like to make.

I then took two plaster casts (left & right) of the main model and made a copy using a very large amount of polyester car filler. These two halves were superglued together and cemented to a 1/2 inch sheet of chipboard with yet another large pile of filler. This rough shape gave me a good starting point to start sculpting, a blueprint was not drawn for this project as all measurements were done directly on the sculpture, working out the positions in 3-dimensions not on paper.

The next stage was to drill and cut the body into sections allowing me to reposition the parts to my own plan. Firstly the lower hull areas, over the wheels, were cut away and repositioned to make the model wider - this was done by gluing the parts to a second board and again filling the gaps. Next the front area was cut off and extended to make the model longer with the bits glued to a third board - to help here a section of the upper hull had to be removed and added back in later, in a revised position.

So began a long process of sculpting and sanding to achieve the shape I wanted. Panel lines, especially the doors, were constantly drawn onto the surface to act as a guide while countless minor modifications were made. The filler made an ideal material to shape but sometimes it was too easy and keeping the shape symmetrical was more difficult without the usual internal bulkheads and wood layers.
The flared wheel covers were added using wood strip and sealed with a coating of epoxy resin. Spray filler was regularly applied as a single colour always helps you to visualise the final look.
The top inlet and dorsal section was left off at this stage as I needed to raise the roofline. It was made as a separate section that could be added to the final model, and cover part of the join line between the two body halves.

After many months I finally decided that the shape was good enough and it was time to move on to the next stage, but I still wasn't totally convinced. I again took two plaster moulds of the master and cast up the halves in fibreglass, trying to keep them reasonably thin. As I still wasn't happy with some of the curves on the front end I put filler into the moulds first, which would allow me the option of later reshaping.

The two sections were superglued together and adhesive tape was run over the join, then resin and strips of fibreglass matting were added to the inside to create a solid one-piece shell. At the same time an internal bulkhead was added to stiffen the body. The rear panel was made from plastic sheeting and blended into the body with filler and the side door was drilled out and removed.

Due to the use of plaster moulds I had to blank off the two intake areas on the master or they would have created an undercut preventing the release of the pattern. As a result these two sections now had to be drilled out and formed using filler and plastic sheeting.

Although both doors are obviously supposed to work only the right one did on the original model (and the toys) so I too copied this feature. Here the door opening has been carefully filed to shape then the edges covered in clear adhesive tape. The door was then put back in place and the gaps filled. It could then be prised out and sanded smooth; more filler was then applied to give the door its bulkier finish.

After a great deal of work the model was primed and I thought I was ready to finally paint it, when it dawned on me that the front wasn't quite right and the sides could still do with a bit more work.
As I build models I hold the model in one hand, close one eye and then move it around to try and get it to match up to classic photographs of the original studio versions. If I can't get the various lines and angles to intersect at the right points then something's wrong and here the front didn't seem long enough and the headlight areas also seemed to be at a different angle. The big giveaway was that the Spectrum symbol seemed to take up too much space; I needed another 3 or 4mm of bonnet space.
Going backwards is always hard, when you are building something there is always that drive to carry on and finish the project, but if you don't fix your mistakes they will always bug you. So the bumper was cut away and the front extended, with the surrounding areas being reworked and the headlight facings angled forward more.

One big feature of the SPV is that it is covered in heavy panel lines, not the usual drawn on versions but actual groves. I was slightly concerned about doing this and possibly making a complete mess of the model, the thought of just drawing them on was very appealing but it would not have looked the same. With the model again primed I carefully drew the positions of these lines and proceeded to cut them in. I started by just running a sharp blade over the surface then moved on to use a fine saw blade to deepen the line. Then I took a broken hacksaw blade, filed the end down to get a finer edge, and used this to get the final grove.

With the model now ready for painting I added the shark-fin to the roof, I'd left it off for a while, as I wanted to minimise the risk of damaging it. The body was now reprimed and painted using Zircon Blue metallic motorcar paint - which now seems to be the recognised proper colour.

Unfortunately when I had finished painting the model I had to admit that the panel lines now looked too big and too deep in places - bugger! Backwards modelling again as I had to sand down and fill many of the lines in, to reduce their overall appearance.
Again the model was primed and spray painted. This time the panel lines looked great - the paint finish however was utter rubbish! For some reason the paint had gone on very roughly, I believe the correct term is an 'orange peel' effect. A friend suggested rubbing the paint down with very fine wet & dry paper and Brasso polish or T-Cut. This worked very well but I put too much effort into it and the paint wore away completely in places.
Still the resulting paint did look ultra smooth, in fact it looked just like the smooth paint finish on the original SPV model, so after yet another repaint I ended up T-cutting the final paint finish.

Wheels are often a problem area on models, especially on something like the SPV which has twenty of the things and in two different sizes to boot. I had been looking for usable wheels for years but with no success. I did come across wheels and tyres with the right type of diameters but they were either the wrong shape, the wrong thickness or had totally different tread patterns. The tyres on the SPV model had a rather square cross sectional shape, and a distinctive tread on the big wheel, so scratchbuilding a copy was the only way to go.

For the big wheel I started with a casting of one of the old RC aeroplane tyres I had used on my SPC model. This gave me the correct general size and sidewall shape, I just had to add a square rim and tread pattern using filler and strips of plastic sheeting. For the small wheel I found a lorry kit with nearly correct tyres, but these were too thin so I had to cut two apart and join them together. As they were only made of thin rubber I filled them up with car filler first.

Silicone rubber moulds were made of these two masters and then used to cast the twenty wheels. The castings were cleaned up and paired off, and then to save weight the inner wheel was hollowed out.
A simple plastic support frame was made to ensure the wheels matched up squarely.

The chassis was constructed from 4mm Perspex and Plasticard, with timber battens placed inside for the base-plate to screw into. This plate was detailed with plastic kit parts, but as the original was actually smooth I kept it minimal. The big wheels were paired off onto simple steel axles. However the centres of the small ones are below the chassis base and a straight axle would have ruined the look of the model from low angles. So I bolted the wheels to trailing arms, that I soldered up from Brass, and they just hang loose.

The distinctive hubcaps were a slight problem in that they appear to be machined in aluminium and shine quite a lot in some publicity pictures. As I don't have the facility to make metal parts I was thinking of asking someone to do these for me.
However looking at normal episodes of the show and 'in action' publicity photos the bright chrome hubcaps are almost always dulled and dirtied down by the effects guys. This is probably because a model with such wheels does actually have the tendency to look more toy-like. As a result I think I actually prefer dirty silver wheels myself and so I just made up some resin castings, from plastic masters, and painted them.

I'm really not sure what these hook things are supposed to be, just that there are two of them under the front bonnet - or there are to begin with. I think ones fallen off in the episode 'Avalanche' and the other goes missing soon after!
I made mine from two layers of 2mm Plasticard. I find that in these cases its easier to just cut the shape into one layer then glue this to a blank second sheet, which can then be trimmed to match when the glues properly set.

The rear panel was now detailed. Thanks to the Dinky toy we know that the rear tracks are supposed to pivot down and give extra traction in rough conditions (not have the SPV travel up a hill in a vertical position as per the TV21 annual!). However this is a feature that was never used in the series even though there are times in several episodes where it would have come in handy - you would therefore have to assume it didn't work and couldn't be filmed. From the start I had no intention of making this a working feature, as we have no idea of what the detail behind the tracks looks like and I don't really like inventing parts on a replica.

The first job was to remove the wheels and tracks from the M-40 tank, one tank will give you the tracks but you need wheels from two toys to do the job. I was in the process of casting some extra wheels but, as I was only making the one model, I decided to take the easy option and just buy two toys.

Most of the detailing on the back was fabricated from Plasticard with the large central loop made from Brass. From the looks of it this simple loop feature is the pivoting support for the two track sections but it actually goes missing in later episodes. Many of the details on this rear panel are from Scalextric trackside accessories kits, such as carjacks, toolbox's and oil cans.

The rear lights are the same as those that appear on the Explosives truck, I cast these two up using red tinted resin. The front headlight bulbs are real but not wired up.

Generally speaking, in television and film, you will find that the internal sets and special effect models do not physically match up properly - if at all! The SPV is not too bad in this regard but there are two problems. First there is not as much room inside as the puppet set would have you believe and secondly the side door would actually have to extend two or three times further than seen on screen in order to clear the wheel housings. Even with these problems people (and myself) still expect to see internal detail so you just have to try and fit it all in.

The first job was to line the inside area with plastic sheeting and create the main bulkhead which goes behind the two seats. Then the twin telescopic arms, that support the door, were soldered to brackets and drilled so that they could be screwed fixed. The door was then temporarily taped into place, the parts lined up and positions marked. Then the frame was glued and screwed to the door and finally fixed to the bulkhead, with bolts allowing for its later removal if necessary. On previous SPV's I've tried doing all this invisibly with dubious results, this time I went for strength and reliability and so didn't care if you can see the odd screw head.

The seats and control panels were fabricated in Plasticard, with the control units being glued to the floor plate that is part of the chassis. Photographs were used for detailing the view screens and instrument panels.

White SPV lettering was spray painted on using masking tape templates. A great deal of care had to be spent here as it really is a one-shot deal and you want them to go on straight. The central letter was done first and then the surrounding two matched up to it.

Note, the inside edges of the upper white intake round off as they merge with the roof, a detail that most if not all replicas and toys seem to miss and yet it's a very obvious detail. A less obvious detail is that the front angled facing is slightly concave, bowing inwards gently along it's short length. This again always seems to get missed but gives the original SPV a distinctive look.

Spectrum roundel's were scans of the original decal, cleaned up and adjusted slightly on the computer, and then just printed out on thin photo paper. The one on the bonnet was made thinner by removing part of the backing paper but I decided not to bother on the side ones as its not that noticeable. Finally the gold centres had to be masked off and sprayed with motorcar acrylic paint.

Silver strips were cut from adhesive foil. I found that they tended to blend in to the surrounding paintwork so I ran a black biro down the edges to make them stand out more. The Letraset tapes were the final bits to be applied. I tend to just buy a reasonably wide tape and then cut it down to the widths that I need, otherwise you end up with lots of different (and expensive) tapes that don't get used for years and then dry out.

Before anyone asks, there are of course two small cylindrical 'thingies' hanging down at the back in the well-known profile photos, they are Scalextric oil cans and funnels but as they do not appear on the model during any of the episodes I have so far not added them to mine.

The aerials are thin steel wires. The tiny black shapes at their base were cut from small sections of Airfix Saturn V rocket engine parts.