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Roxey Mouldings LBSCR 54ft Tri-Composite - A first venture into Brass Kit Building


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Good morning(!) to you all!

 

Yesterday, well Saturday at any rate, I bought myself a set of Bachmann ex-SECR 60ft Birdcage coaches in SR Lined Olive, and very nice they were too. However, by some extra trading I managed to have some money left over, which I didn't expect! And on one of the shelves in the shop, this caught my eye...

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Being a modeller of the early years of the Central and Eastern Sections of the Southern I thought, given the price and the fact that the kit was new and unbuilt, still properly wrapped, I'd go for it. Now, this isn't the first brass kit I've built (I've previously managed a 7mmNGA Slate Wagon with success but also with assistance), nor is it the first I've owned (I have a set of Rod Neep MS&LR Coach bodies sat in a drawer that I picked up for £6 and have kept for practising such things as curving tumblehomes - more on that later), but it is by far the most advanced and complex.

 

I thought I'd create this separate thread in what may be a more visible area of the forum to see if I can get some help as I go along, indeed my first question is if anyone has any advice before I make a start? The kit's (1984-dated!) instructions recommend the use of solder paste, which will be a first for me, and I can see why, looking at some of the finer bits. I certainly intend to solder the kit together, by the way (other than the plastic bogies and whitemetal castings... :O ).

 

Now, my main concern currently is how I go about forming the tumblehome, and this I will practise with the MS&LR 6-Wheelers before I look to try it on the LBSCR Tri-Composite. One idea I have had so far is to photograph or scan the coach ends, import them into CAD software and use them to draw a hollow cylinder with the same radius as the tumblehome. I can then 3D Print this cylinder and use it as a former to curve the brass. Another version of this was to make a sort of jig/former that the side sits in, with a curved section matched to the radius of the tumblehome and a corresponding piece that applies pressure and thus creates a smooth curve. However, people have been building these kits for years so I assume that there must be a perfectly good way of doing it as it is - I would be interested to hear them!

 

Another thought I have had is to build the basic coach body and then spray it into SR Olive Green, before adding things like the droplights in the door windows (which I would paint brown separately) and the door handles. Is this a sensible idea or not?

 

As will no doubt be clear by now, I am very new to this brass kit-building lark, but I hope to learn as I go and having spent £30 on it I also hope to have a usable layout-worthy coach by the end of it!!!

Edited by sem34090
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Hope all goes well.

 

To be honest if you print a former of the correct diameter it will not form the brass at that as the brass will spring back.

 

A couple of easy ways to do the turn under is tape the bottom edge of the coach side to a broom handle (masking tape),  then roll the handle over the bottom of the side. Easier to do than describe.

 

Or on a flat surface put the bottom edge face down on the edge of a 12" rule laid flat. The with the back of a Stanley knife or similar run it along the side close to the rule.

In 4mm I always used the former.

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I use a 1.8cm diameter smooth metal bar like a rolling pin, with the carriage side mouldings face down on a soft mouse mat. I apply gentle pressure whilst rolling and the side gradually takes on the necessary shape. Whatever you use to apply the curve, it must have a smaller diameter than the actual curve wanted, as the brass will spring back slightly. Just take it carefully whatever method you try.

Cheers Ian in Blackpool 

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Whilst I have not built any coaches (yet, like you I have a number of old Roxey kits to build) I have built a number of brass loco's that require lots of bending to a profile. The advice received is sound, I use various diameter dowels of smaller diameter than the required profile and progressively roll the brass section to profile. You have a template, the end of the coach, to compare with. 

 

As to painting, that's  the way I would do it but no doubt there are many coachbuilders out there that have much more experience than I do!

 

Kind regards,

 

Richard B

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I am a tumblehome vandal.  I place the coach face side down on my cutting mat and then roll a 1cm diameter brass tube across the appropriate bit.  The mat has very little give, so several passes of the tube are necessary to get the end result right.  However it works for me.

 

Solder paste is definitely the way to go with kits like this.  Tin both surfaces and then bring the together with extra flux and the two pieces should fuse together.

If you are soldering the droplights in place I would have thought pre-painting the sides would be a no-no unless you like blistered paint.

Why are you not soldering the white metal castings?  Soldering is by far and away the best way to fix these to brass.  You should however make sure you have access to  temperature controlled iron - and IMHO the best are those that actually control the temperature rather than those with a pot to control the current.  I recently replaced my old unit (of the latter type) with a proper temperature controlled unit and the difference was amazing.

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You'll get advice from differing members, some seemingly contradictory.

 

Forming the coach side turn under can be done in a number of ways as described although occasionally the brass used for the etch may be rather hard and require a bit more effort.

 

Andy's recommendation for a TCU (usually at least 50 watts) is valid but with a good 25 watt iron, 145 ° and a liquid flux (available from various suppliers, I use LRM solder as it flows well), you can still readily assemble a coach kit. Solder paint or paste tends to have higher melting points (generally around 188°) so a more powerful soldering iron helps with that. The separate soldering iron temperature controllers restrict power to reduce temperature. A TCU controls the temperature but full power is available at all times, which is what you need to get the solder to melt and flow as the metal you are soldering conducts the heat away from the iron tip, lowering the temperature. Apologies if this is teaching you to suck eggs, but it is where many people suffer problems with their first kits.

 

I prefer to solder the droplights in place and brush paint them after spraying the overall body livery. However, I use an airbrush for primer and top coat, so can control the paint coat thickness. If you intend using rattle cans, the paint can go on rather more thickly and "fill" corners of windows, beading, etc. Adding pre-painted droplights afterwards might be better in that case.

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The Roxey sides have substantial flanges top and bottom. This means that you can form the turn-under to a slightly larger radius than required and then spring the bottom of the side into final position when soldering up the body. I.e., solder the straight bit of the the side to the ends first and then lay the coach on its side and roll it slightly to close up the gaps at the bottom. This is easier if the door hinges are left off until the body "box" is assembled. The flanges are essential for this technique: if there are no flanges, then the side will pleatt around the partitions at the bottom.

 

I find that I always get slight errors when rolling the turn-under and it's easier to correct an under-rolled side, as above, than an over-rolled one.

 

It's nearly impossible to roll a side with the bottom flange folded up, so that flange has to be bent up after rolling. However, there's a danger of distorting the top, flat part of the side and it helps to form the top flange before rolling.

 

I've had disasters with solder paste where some of it didn't get hot enough and the residual flux rotted the joint over a number of months. I prefer pre-tinned parts and solder flowed in, by capillary action, from the edges of the joint.

 

If you wanted to innovate, you could print an armature for the coach body and assemble the sides and ends to that as glued overlays. I've done this with a wooden armature so I know it can work, but it's arguably easier just to solder up the monocoque...

 

...provided that one can avoid the 15 flavours of monocoque-up caused by the lack of positive alignment in the kits. In the last kit I built, I soldered in a fragment of brass angle along the end of the side (using high-temperature solder) to strengthen the side-end joint and to give alignment. That made life much easier in the main assembly.

 

 

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Here's my build thread for a couple of these kits: 

I'm afraid it's more of a 'I stuck the kit together as per the instructions and it was really easy because I've built loads of etched kits' summary than a detailed guide, but it does have some photos showing the kit under construction.  

 

As for the sides, these were relatively easy to form as the brass at the bottom is half etched and quite thin. The folds at the top and bottom were made using a home-made set of bending bars - basically 2 bits of L section aluminium about a foot long, with a nut and bolt at each end. Tighten the bolts with the half etched line in the right place, put the whole thing in a vice, and then make the 90 degree folds using a ruler. 

 

I really like Roxy coach kits - they always go together well. 

 

 

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On 23/04/2019 at 09:16, Guy Rixon said:

In the last kit I built, I soldered in a fragment of brass angle along the end of the side (using high-temperature solder) to strengthen the side-end joint and to give alignment. That made life much easier in the main assembly.

 

I did that in the very first brass carriage kit I started building, a D&S NER 6-wheeler. The next one I had to face up to doing without, as it was an all-third with too-narrow end panel for the angle. But I haven't completed that or any other brass carriage kit...

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