Scratch Building

In this section we'll take a look at scratch building and kit bashing; the art of building, or modifying your own bodies and chassis to make a slot car.

This is another huge subject in it's own right, with each builder having their own personal techniques, and methods of creating their own unique masterpieces. So our aim here is not to cover every possibility, but to provide a small taster, by showing you how one builder makes their own hand carved body.

Basics

To scratch-build or kit-bash a slot car, there needs to be a body, a chassis and the necessary running gear. That's the case for any scale of slot car and whether the aim is to race the car competitively or not.

The body can be crafted from scratch in many different ways, such as carving wood (as shown below), plasticard construction, or using moulds. Alternatively it can be adapted from a plastic kit or bought off-the-shelf as a resin, fibreglass or lexan shell. A body usually requires painting and detailing to produce a slot car model that is unique and personal to the builder. Decals for thousands of cars are available to buy or can be designed and printed at home.

Sometimes a chassis is supplied with a kit (eg George Turner's kits), but there are also many adjustable 'universal' chassis that can be used (eg Pendle's PCS32, Penelope Pitlane, Slot.it HRS2, MRRC Sebring, numerous metal racing chassis etc etc). Some builders will find a chassis from another slot car model that will fit or can be adapted. And there is always the option to make your own chassis from scratch - using metal, fibreglass board, plastic sheet or 3D printing.

There's an enormous variety of running gear available to scratch builders and kit-bashers, although most of the adjustable chassis can be bought with all the necessary components included.

Building a Maserati

This article shows how one man built a Maserati Streamliner from a block of balsa wood, using simple tools.

Maserati Streamliner

Building a Slot Car Body out of Wood

By Gordon Steadman

This is not intended to be a definitive guide. I am not a professional pattern maker, just someone who does this for his own pleasure.

However, I’m sure the basics apply. I suspect, that if you have two left hands or ten thumbs, making your own bodies might not be a good idea. For someone with a practical bent and a good eye for shape and form, using a slot car with a body you have constructed yourself, offers a whole different sort of satisfaction.

The Wood

The choice of wood is fairly important. If you are making a pattern to be used for resin casting or vac forming, the weight is not important. For minimum weight, you just can’t beat balsa. It, as most things do, has advantages and disadvantages.

It is very soft (although strictly, a hardwood) and so carves and sands very easily.

On the other hand, it is very soft! It is easily damaged and splits very easily along the grain but is pretty strong across it.

Drawing

The method will be the same whatever wood is chosen. First, a drawing is needed. I’ve posted quite a few on this forum but there are a few sites around that have them. Some for sale and some free. The free ones are usually low resolution but that doesn’t really matter for our purposes.

I’ve chosen to do a Maserati Streamliner in 24th scale. No drawing that I could find but as the original is based on the 250F that is a good starting point. The first thing is to make it the right size! Most of the drawings are 32nd scale. I used Adobe InDesign to increase the size and then print out the result. I just drew the streamlined body over the original.

Scale Drawing

Gluing

I used PVA woodworking adhesive to join the sheets of balsa. It’s important to clamp them properly as the soft wood can curve and the join wouldn’t be strong.

Gluing the blocks

Tracing

The side and top profiles are cut out of the drawing, and the side outline traced onto the wood. In this case, the size dictated that I use solid wood although it would save material to try and build up the sides separately.

Tracing the profiles

Cutting

If you have a bandsaw, it’s the easiest way of cutting. Mine isn’t working so this was done with a Japanese pull saw. Cut just outside the line. Sanding will reduce balsa quite quickly. Once the side shape is done repeat the cutting out for the top profile.

Cutting out the shapes

Carving

From here on in, you are pretty much on your own as the shape will have to be arrived at by carving and sanding. I use a scalpel, rasp and file. Constant reference to photos is essential.

Refining the Shapes

Plasticard

As balsa is so brittle, I insert plasticard where there is likely to be a problem such as the quite thin edges at the rear. Also, the raised lip in front of the cockpit has quite small vents and there is no way that the wood would survive those details. Plasticard is also useful if you want small details such as door handles. It’s very easy to cut a slot and superglue the plastic in. By the way, whenever using plastic, always wet it before using superglue. It will then grab - the same way it grabs the moisture in your skin - and hold much better.

Plasticard Details

Sealing

Once you are satisfied with the shape, the car has to be sealed and painted. My method is to soak the balsa in superglue. It goes on reasonably smoothly if you rub it with the tube as you go along.

One thing to be careful of - no two things. The first is that the combination of superglue and balsa gives off fumes. Best not to lean directly over the body as you put the glue on. It also gives off heat and, although very unlikely, it could catch fire so just keep an eye on it.

Sealing the body

Next, it’s all rubbed smooth and will look horrendous and patchy. I use 120 grade for the first sand. Another coat of glue, rubbed down again and then a first coat of colour. This will show up every imperfection. Any deep ones will need filler. Two sorts I use. The quick way is to sand some balsa - end grain on, it cuts quicker - and use the dust as filler. Drop some superglue onto the hole and drop some sawdust over it. It will go solid immediately. Then be very careful with the sanding as that patch of filler will be harder than the surrounding surface and it will be easy to lower that too much. A slower and safer method is to use Milliput. I lack patience and find waiting for it to cure rather a pain.

Painting

Most people will want to use an undercoat but, being a cheapskate, I use cheap paint cans from our local builder’s merchant and just rub away until it’s smooth.

Painting the body

Once the surfaces are smooth and flat, then top coats can be applied. I won’t go into that as I’m sure we all have our own ways of achieving a decent finish. My secret is elbow grease.

Glazing

The one thing I always have trouble with is the glazing. Fortunately, on this one, the glass fits inside rather than flush so it was easy just to use some contact adhesive. The glazing in this case was part of the packaging from the contact adhesive!

How you fit the chassis is another subject. Being a woodworker, I use a hardwood block glued in and wood screws.

The Finished Model

Maserati 250F Streamliner

Find out more

There is a lot more info and advice in the "Scratch Building" section of the Forum, as well as some stunning builds.
Scratch Building

Pendle Slot Racing stock a huge range of useful parts for scratchbuilding, as well as a good range of kits and bodyshells..
https://www.pendleslotracing.co.uk/

George Turner Models make some wonderful kits.
http://www.georgeturnermodels.com/

Patto's Place is a popular destination for sourcing decals.
https://www.pattosplace.com/

Indycals is another good place to find decals.
https://www.indycals.net/