I should also give credit the person who taught me the technique in the first place, a fine modeller of the Colorado narrow gauge, Mick Moignard.
The first stage is to have a scale drawing of the carriage you are going to make - in this instance an FR 'Barn'
Sellotape the drawing beneath a sheet of thin glass, such as that used in a picture frame.
Cut a piece of styrene to the dimensions of the lower, solid part of the carriage bodyside and tape it in place as accurately as you can above the drawing, like this...
I usually use 20 thou styrene for this base layer. On its own it's pretty flimsy but this technique is about building up a laminate structure so it will become stiffer as the build progresses.
Next we add the window pillars. I recommend the Evergreen range of styrene strips which come in such a wide selection of widths you will surely be able to find some which match the width of the window pillars on your carriage. (I typically use 0.40" strip which is 1mm wide)
Here is an excellent tip for placing and cementing the pillars. Lay a ruler against the edge of your piece of styrene and use it as a guide for getting the window pillar in exactly the right spot. Dab a tiny spot of solvent on the joint (let capillary action do its work) and gently slide the ruler away.
Make the pillars longer than they need to be. Work along the carriage from one end to the other until all the pillars are in place - like this...
Now mark where the top of the pillars should be at each end and lay your ruler in position on top of the strips and work along chopping them to length. Then position a long length of strip along the top, hold it in place and once more dab each joint with solvent working along from one end to the other.
In this picture below you will also notice there are two horizontal rails towards the top of the carriage. It is the upper one to which I have just been referring. The lower rail is made by cutting pieces of strip to fit between the pillars and glued in individually.
And here's my tip for doing these. Use a tiny off cut of strip which is the width of the gap you require and use it as a size guide to ensure each horizontal bar is glued in at the same height. Make sure it does not fill the space - that there is a gap at either end - then providing you do not use more than a dab of solvent on the joints at each end you can easily lift it out with the tip of your blade and move it along to the next window.
If your design has square framed windows then you can now peel off the tape from the lower panel. You will find that the piece is still stuck to the glass because a little of the solvent will have leaked between the styrene and the glass when you were attaching the pillars. All you need to do is slide the tip of your modelling knife underneath - like opening a breakfast cereal packet - and it will pop off the glass.
However if you need some curves in the corners of your windows leave it in place on the glass for now and follow these steps.
The idea is to glue triangular off-cuts into each corner and use a needle file to round them off. I make the triangles by making a series of 45 degree cuts on a piece of 60 thou strip.
This picture shows you what it looks like with the triangles glued in place and what it looks like once they're filed down.
Here's a tip for holding the piece during the filing.
I use my tweezers as a vice cum handle and grip tight on the pillar I want to work on - it means you have a much stiffer surface to file against and it means you are much less likely to snap the joint that's holding the pillar in place. You may find during this process that a couple of the triangles become detached as you file them but all you have to do is lay the bodyside on the glass and glue it back into place and try again.
A note about how to store these pieces between sessions when you're working on them. It pays to keep them as flat as possible so I keep them in an old fashioned photo album (with the film which peels back from the pages) and put the album beneath some other heavy books.
So now you're ready to add the second layer of detail, which is usually the beading / panelling on narrow gauge rolling stock. For this I use 15 thou strip although you could go down to 10 or even 5 if you were looking for an effect more like a half-etch in brass.
I usually begin with the long, unbroken, horizontal runs along the top and bottom of the bodyside. In this picture you can see how I make use of a thick metal edge to keep the strip up against the edge of the piece.
From here on it’s simply a case of adding as much or as little beading is required or desired – cutting each piece to size and gluing in place. There is quite a lot on the latest build of Barns – there is a vertical strip beneath every window pillar on the lower bodyside.
You will also give your carriage side much greater rigidity if you add a second strip on each of the window pillars too – this is quite correct if you look at the prototypes carefully.
(Although having said that, on my first generation of scratchbuilt Barns I didn’t bother with adding strip on the window pillars. You didn’t really notice on the layout unless you looked closely – but they were much less rigid)
You’ll also want to add detail to represent the doors. I do this by just adding a square on the lower body panel. So what you should end up with is something that looks a little like this.
Some final points before you can consider your carriage sides finished.
If the carriage has droplight windows (the Barns do) then turn it over and add a third layer of strips to the rear of the window pillars – overlapping the windows so from the front it represents a droplight.
(In effect you’re doing exactly the same in plasticard as you do with a brass kit where you solder them on the back of the windows)
If you’re fitting handrails or door handles it pays to drill the holes now before you glue up the sides into a bodyshell.
You should still keep the bodysides in the photo album or in another kind of press until you’re ready to glue them up. With the beading forming a laminate as the solvent cures it will cause the side to curve up like a banana. This is actually a good thing for making it more rigid later on but it’s still best to force it flat for as long as you can..
For making the ends, if you don't already have one, I would recommend investing in a compass cutter.
These ends can be detailed up with beading in the same fashion as the sides.
If you're making something like an FR observation carriage, with windows in the end, I treat these like a miniature bodyside and build them up by gluing on each pillar.
At last the moment has arrived where you get something that begins to resemble a carriage.
Glue the four pieces up so the end of the bodyside is glued to the back of the end pieces
Becuase of the natural tendency of the styrene to warp as the solvent cures you'll find you've got something which looks like two back to bananas!
Fear not! This is what the roof and the floor are for.
With this method of scrathbuilding the roof and the floor aren’t just there to make the model look pretty, they are vital structural components and function is more important than form.
You’ll want to make you floor out of the chunkiest plasticard you can – I use 60 or 80 thou sheet.
The floor will fit up inside the bodyshell – and you want to cut it to be a perfect push fit because you want it to stay in place on the finished model without glue.
Because the floor sits up inside the bodyshell it keeps your naturally banana-shaped carriage body straight. And those sideway forces from the carriage sides should grip the floor and prevent it falling out.
Next, measure, mark and drill the holes for the bogie pivot bolts. I arrange mine so a 10BA bolt goes down from inside the carriage and a nut secures the bogie underneath.
I also add a 60 thou piece of plasticard as a bolster to stop the bogie rubbing on the floor.- I glue it in place over the hole and then drill again.
You might be wondering what stops the floor disappearing all the way up inside the bodyshell?
My solution is to glue three blocks at intervals along the inside of the body – at each end and in the middle – which the floor rest against when the carriage is on its wheels.
It may help your calculation when include the thickness of the floor to remember each 20” of plasticard thickness is 0.5mm.
It’s also vital they are positioned accurately to keep the bodyshell level on the floor/chassis when it’s running.
Here's how it looks from beneath..
Now for the roof.
Once again it’s a vital structural member. Just as the floor’s job is to keep the bottom of the bodyside straight, the same happens at the top with the roof.
I’ve always made mine out of plasticard but it’s quite possible you could make them out of brass too. To do that you would need to solder two strips along the underside which would have the dual function of locating the roof properly and forcing the sides to stay straight
First I cut a piece of plasticard to the same dimensions as the floor which will be a perfect fit inside the bodyshell. This is what keeps the sides straight. I’ll usually use 20” sheet for this.I glue three ribs along the length of the roof and use a file or wet and dry paper to shave them down to match the profile of the roof.
Then I’ll cut a slightly wider piece which will sit on top and slightly overlap the carriage sides. I carefully glue one on top of the other making sure there is equal gap / overlap at either side.
At this point you could also choose to fix on a curved a brass roof skin – that would work perfectly well.
The final step is to force a piece of 10” or 15” plasticard sheet to bend over the top.
I measure and cut a piece of sheet which is larger than I need and slop a generous amount of solvent along one edge of my roof skin piece and press edge of the flat, bottom structure, down onto it and keep pressing down for at least 5 minutes until it’s very firmly fixed.
I leave it to fully cure for a while, then, with the roof upside down on a hard surface (so I’m pressing on the bottom of the flat section) I rock it over, forcing the plasticard to curve over the ribs and glue generously on the other side – once again pressing down very hard and not letting up for quite a few minutes.
Usually some part will succumb to the laws of physics and come unstuck, but you can apply more solvent and press down again and eventually it will submit.
I then sand and file it down to the correct dimensions over the sides and ends.
I tend to glue my roofs into place – it makes the bodyshell very rigid and it guarantees to top of your bodysides will stay straight and true.
I also build interiors for the carriages, fixed to the floor which also have a dual function of keeping the glazing fixed in place without the need for glue and at the same time forcing the bodysides to stay straight and true.
And evenutally I end up with something like this..
I hope you've found this guide helpful. If there are points I haven't covered or you have questions about an aspect of my technique etc please get in touch (such as via the comments section) and I'll be delighted to try and help.