DOORS TO MANUAL

The 7mm AY ballast wagon build continues.

Attention's turned now to the underneath and the ballast spreading / hopper doors unit.

On the 4mm verions I completed recently I cheated and only modelled the exterior details because the wagons were built with the intention they would run permanently loaded.

However this time the client wants wagons in which he have removable loads which means I'm going to have to include all this.....



And some pics of the progress so far...

AND NOW STRAPS TOO

It'll soon be time to tackle those beastly ballast doors....

STRUTS

I think that it's when these Z shaped struts are added that a rather nondescript model becomes unmistakably an AY ballast wagon.

FROPPERS

Silly title - serious progress.



The frames and the hoppers have been united, so they're begining to look a little like ballast wagons now.

I've also made up a jig to fabricate the Z shaped braces at each end.

(The title's my made-up word combining frames and hoppers in case you were wondering)

FRAMES

The frames for the ballast wagons have been glued together.

Gosh! 7mm models are such huge things compared to 4mm, they only just fit on my workmat.



The next step is to fix on the footplates at each and then add on the end beams which will need holes for the the couplers to fit through.

AY UPDATE

Some steady progress on the 7mm ballast wagons this weekend.

The slanting lips have been added to the top of the hopper bodies.



Already the difference in working in 7mm as opposed to 4mm (009) is becoming apparent. There is a small gap on the inside edge where the lip rests at the top. On the 4mm wagons I could deal with this by brushing in some styrene dust and running a little solvent over it, but that won't work in this scale so it's out with the tube of filler.

The second task has been to cut the pieces of styrene strip and channel which will be fabricated into the main frames of the wagons.



The main side beams have already been laminated with much thinner sections of strip to form the stepped L profile.

GO LARGE

An exciting and challenging new commission. I've been asked to build another pair of the Welsh Highland Railway's ex-SAR ballast wagons - but this time in 7mm scale.



It's the first time in 20 years of narrow gauge modelling that I've built stock in anything other than 4mm so it's going to a fascinating experience for me.

The basic hopper bodies have been knocked up out of 0.60" styrene already, and I have to say they do seem rather big. It's strange to be working on something you hold using your whole hand rather than just your fingertips.

I'll be blogging on the progress on the wagons here so keep dropping by if you're interested in finding out how I'm getting on.

A CARRIAGE COMES TOGETHER

So here we are with the final installment of this stage by stage account of how I build carriages out of styrene.

With the detailing work completed on the four sides and ends the last task before they can be glued into a box is to fix some locating blocks for the chassis / underframe on the back of the bodysides. These will make sure the body sits at the correct height.



And then - cue drum roll - Ta Da!



Add on the bases for the chassis and the roof and finally we have something that actually looks like a carriage.



Now, you've probably noticed that so far the roof is flat and might be thinking that that's a little odd.

You might also be wondering why I don't just bend a sheet of brass and make a roof out of that?

Good questions. Here's the answer.

Styrene - or plasticard if you prefer - is the Devil's own material and has a mind of it's own and it won't stay in shape unless you force it to, by altering it's molecules through heating and cooling them or alternatively by keeping it stressed. Here I'm using the second option.

So I make the roofs with a twin layer flat base. The lower layer is cut to fit inside the bodyshell - this will keep the sides under stress and stop them bending inwards (or outwards too once the roof is glued on). It will also help to make the whole carriage body more rigid.

The second layer of the laminate is cut wider to sit on top of the bodyshell.

Flip it over and you can see I've added a thin strip a few mm's in from the edge.

Any guesses what that's there for??



Those strips will help locate and hold the glazing in place when the model is finally assembled after painting. Keeping the glazing held tight against the inside will also prevent the bodyshell from warping inwards over time.

Now attention turns to the top side again and I glue on 3 trusses along the length of the roof. These will support the roof skin and keep its shape and stop it sinking in the middle.



Then a final piece of styrene sheet can be bent over the top to complete the roof skin.



It's one of the most tricky jobs of the whole project. The styrene will bend easily enough but overcoming the fierce natural spring in the material and getting it to stay bent is much harder.

What I do is glue one edge down and wait for it to set firm (perhaps as long as half an hour) and then test out attempting to bend it over the formers. Inevitably this will expose some weak points along the joint where it opens up. So I re-glue those areas and repeat the process until the styrene can be bent across to the other side without any lifting.

Then, being very generous with the solvent, I put the roof upside down on the workbench and roll it over and press down very hard on the second edge. Easing the pressure off will once again expose any sections that haven't bonded properly and I go back, apply more glue, more pressure until, finally, the styrene submits.

I've made that sound a bit of an epic battle - man against styrene - but the good news is that once you have got the roof skin to bond it will stay bonded. Although I am putting the styrene under great stress I have carriages that I made 20 years ago in this way and the roof skins have never lifted once.

You've also probably noticed there's a triangular cut out in the roof. That's where the domed end of the roof - a feature of the FR's Observation Carriages - is going to go. More on this later.

Let's turn our attention back to the underframe.



Here you can see I've added a strip around the edge which represents the main steel underframe of the carriage which pokes out beneath the wooden body, and also the truss rods have been bent up from a length of brass rod and glued into place.

And on the other side...



Those upright rectangles of styrene are going to hold the glazing in place at the bottom. Normally this job would be done by the interior, the seats and tables etc but the client has specified a carriage without an interior so these lengths of strip have been added instead.

Now it's back to the roof and time to form the domed end using that fabulous modelling material, Milliput.



It's wonderful stuff. Firm enough to be pressed into shape. It can be smoothed down with water. Won't shrink or crack and it sets like rock (after 24hrs). The best modelling filler I've ever used.



So now I'm just waiting for that to set so I can rub it down with with some wet and dry paper and then the roof can be glued in place and that'll be it. Job done!

BACKSTAGE

There's been some steady progress to report in the build of Observation Carriage 100.

The detailing has been completed on both bodysides and the glazed observation saloon end piece. The main outstanding item is making up and fitting the corridor connection pieces for the other end. Then they can be glued together into a box shape and it will finally start to look like a carriage body.

As I explained in an earlier post, each bodyside is a three-layered laminate. What I'm showing you here this time is the third layer, which gets put on the inside (or the back) of the bodysides and represents things like window droplights or blanked-out panels.

In these pictures you can see how this third layer of the sandwich is seen from the outside of the carriage and also what has been glued on behind to create the effect.





As you can see, the work on the reverse side is a lot rougher and less exact than on the viewing side. Just like going backstage at a theatre or film set all that matters is what the audience sees.