Ian_C's workbench - P4 and S7 allsorts

The 8F is gathering dust at the back of the workbench. Needed a break from it. I'll be in the mood again at some point. Thought I'd do a 4mm quickie project. A 1/108 using a Parkside body and a Rumney chassis (B 13) ought to be a quick and simple project. Of course they never are quick and simple. The Parkside body takes minutes. The Rumney chassis somewhat longer, but without any snags. What I hadn't realised when I started was that I didn't have all the parts for the wheels and bearings. My preference these days is for the Exactoscale type parallel axle and bearing (they stay where you park them!). I've been living off a supply of Exactsocale parts for years, but they're running short now, and not enough matching parts to make up a wagon set. In the end I restocked with the current incarnation of the Exactoscale axle/wheels/bearings from the Scalefour Stores. The combination of 4CW104A wheels, 4CW501A axles and 4CW603B 2mmOD bearings matches up perfectly with the Rumney chassis and suspension parts, and avoids the tedious job of trying to find four identical pinpoint bearings and work out the spacing needed to fit them neatly between the axle guards. All goes together nicely and glides smoothly along as only suspension can. Naturally there's a photo...

It's the one on the right of course.

All pretty vanilla stuff. The weight is a rectangle of 1.4mm lead flashing which, when cut to drop into the floor of the wagon, weighs almost exactly 30g, and brings the all up weight to around 45g. You don't notice the lead floor when it's painted. Buffers are from Lanarkshire Models & Supplies. Spring and axle box castings are from goodness knows where. 3 links are from the old Exactoscale stamped hook and drawbar with home made brass wire links. I usually make a coal load when I make the wagon. The load is a block of rigid insulation foam carved to a suitable shape, twin peaks being the fashionable configuration right now obviously. They'll be blacked and coaled with sieved scale coal lumps eventually.

The 24 1/2 tonner on the left was completed a while ago. I rather like it. Just showing off really.

The 8F though. Fall plate to make, and I'll have some work to do to get the Modelu crew to sit and conform naturally to the cab. Sometime soon.

 

S'pose that's the power of WT. Having just posted some vaguely intentional waffle about getting round to making the fall plate for the 8F, I've got off my backside and done it.

The kit has a fall plate in two parts; an etched plate profile and an overlay with a chequer plate pattern etched onto it. The idea is (I think) to sandwich a length of wire in a half etched rebate along the back edges and somehow use that as a hinge along with the tiny lugs projecting from the rear of the cab just beneath floor level. Two problems with that; the resulting plate will be way over scale thickness (and you do see the edge), and I can't see how you'd assemble it and make it work. Cartoon light bulb hovering above head, and this is how I made it work.


I elected to use only the chequer plate etch, it's plenty stiff enough on its own.The plate was profiled and curved to an approximation of the prototype and some tiny lengths of brass tube were silver soldered to the under side to sit between the lugs on the back of the cab. The tube was about 1.0mm OD and 0.6mm ID.


You can see the four lugs in this photo. The cab's upside down by the way. Two 0.6mm holes were drilled in the rear plate, red circles mark the spot.


Small rectangles of brass shim were RSU'd into position on the upper surface to represent the prototype hinges. On the prototype the fall plate was actually 2 plates split in the centre. I've left it as one piece for simplicity. The hinges are completed by lengths of 0.4mm phosphor bronze wire.


Some fiddling, and the plate is fitted in position with the wires. 0.4mm wire in 0.6mm holes makes a nice sloppy fit that eliminates any tendency for the hinges to bind.


The bent ends of the wires are sprung into the holes drilled in the cab . Phosphor bronze wire is springy enough to let you get away with that if you choose the length of the bent end carefully. Easy to take a part as well.


This is the plate assembled to the cab, seen from above. It hinges up and down freely under its own weight and will just rest on the tender. Turned out to be easier than I'd feared.

Need to find the finishing off list and see what's left to do.

 

There are four hoses that connect the loco to the tender and are to some extent visible in a side view. Two water hoses leading to the injectors, the vacuum hose and a tender steam brake hose. Unusually I'd actually thought this out ahead of time, and left features in the correct location on the back of the chassis beneath the cab that were easy to connect dummy hoses to.


The two water hoses are at the extreme left and right are connected to the lugs and bosses I'd made previously. The vacuum hose is connected with a small turned collar to the end of the vacuum pipe under the cab. The water and vacuum hoses were made from 2.0mm and 1.6mm brass rod respectively. There's a basic representation of the vacuum hose coupling at the bottom of the loop. The profile of the hoses was scaled off one of the Wild Swan drawings and drawn in 7mm size on a scrap of paper. The brass rod was bent gradually until it matched the sketch. Because the hoses are spigotted into flanges they're quite robust when soldered in place. Here's hoping...


This is what you see from the side at about scale eye level. I didn't make a steam brake hose because the electrical wires represent that in roughly the right position. Sort of. What's apparent in this photo is the see through gap where the buffing block and plates should be on the drag beam. I'll have to make something to go there and block the view without restricting the articulation. That's part of the modelling challenge - seeing daylight where there should be daylight, and not seeing daylight where you shouldn't!

Freddy fireman is contemplating the dent in the tender side that's been filled with Isopon. It's 1966 mate, I'm surprised anybody even bothered to fix it. A few more months until withdrawal and the scrap line.

 

Nearly, nearly complete. Seemed like time to put it all together for a preview. It's such a performance to assemble it all that I've rarely bothered during the build. It's so long since I've worked on some of it that it took some head scratching to get it all together. Not helped at all by an indisciplined approach to keeping all the loose parts along with spares and misfits in the same container. I mean, what are all those washers and spacers for? I can't imagine where they all go. I had to refer back to some WT posts to figure out the assembly sequence for the tender chassis. There'll need to be a Haynes Manual for this thing, or at least some assembly notes. Needless to say, I found a few small jobs to finish off as I put it together. And having got it together and taken some photos, I can see a few more. For example the clamps for the cladding bands on top of the firebox, and the little collars on the end of the handrails. Here it is, cruelly exposed.








Next I need to give some serious though to painting it. How do you go about painting a loco in grubby BR grey? I'm not sure Halfords grey primer and a coat of satin black gets the desired result.

 

The original cunning plan to hinge the cab doors with phosphor bronze strip didn't work out well. The endless faffing connecting the tender drawbar and then disconnecting the tender drawbar was hard on the cab doors flapping around out back of the loco. Eventually one came unsoldered. Rather than refit it, I needed a new approach that allowed them to articulate, kept them lightly sprung closed when coupled to the tender, and allowed them to be removable to work on the loco.

The following photos show how it ended up. The two sections of the door were soldered permanently together. A length of microbore brass tube was soldered to the cab wing plate. Two shorter sections of tube were soldered to the door. This was done with the door held accurately in situ with the short tubes threaded on a 0.5mm wire hinge. The short tubes were then soldered to the doors, being careful not to solder the whole shebang solid. A spring was made by wrapping 0.3mm phosphor bronze wire round a 0.5mm drill bit to form a loop. The spring is retained by the hinge wire passing through the loop. One end of the spring is soldered to the inside of the door, the other is tweaked to bear lightly on the inside of the wing plate. Seems to work, and the whole door can be taken off by removing the hinge wire. Not prototypical in appearance, but it's not too visible and it's robust.



Painting then. Some kind souls have suggested that the model's good enough to be blessed by Martyn Welch. Not sure about that, and not sure I could afford it either. Besides, I'm determined to do as much as possible myself. There's always paint stripper if things go horribly wrong. There's a lot to think about before even starting to paint anything. Here's what's percolating at the moment...

• I'll need somewhere dust free to keep it between painting sessions. Usually I just leave freshly painted models somewhere where they won't be disturbed and there's not much dust. 'Not much dust' = 'some dust', and there's usually remedial work to do. I'm thinking of making a drying box, which will also be useful for other model painting activities.
• I have some fresh Phoenix 2 pack etch primer in black, so that'll be the first coat on most of it.
• 'Proper' primer on top of that, or not? I'm thinking a grey micro filler primer may be needed to show up areas that need some work before the base colour. Also with a mid grey base it'll be possible to do a little zenithal highlighting by varying the density of the base black colour on top of it.
• The other decision at this point is whether to go acrylic or solvent base. I'd prefer the base colour to be solvent based paint to give a more durable surface for weathering effects. Therefore the underlying primer needs to be solvent based as well. May use some of the paints I've used for car modelling. Zero Paints make some excellent paint. They don't do railway colours, but black's black innit?
• Been doing some reading about scale colour. Seems to be a thing in the aircraft modelling world. Makes sense that objects at a distance appear less saturated due to atmospheric haze. Logically therefore the loco isn't going to be absolute black, and I'll experiment with fading it a little with a neutral grey. See, it really is going to be BR grey!
• Decals over that. Cab side numbers, tender emblems BR late, electrification warning flashes. Who makes the thinnest decals I wonder?
• Clear coat over the decals to protect them from the mayhem that follows.
• Then weathering. I will re-read Martyn Welch's book on the subject, but I'm inclined to use some of the military modelling techniques and materials I've picked up.
• Find some decent photos of a loco in the condition I want to portray, and paint what you see.
• At 7mm scale I think texture starts to play a part in the appearance of a model. There'll need to be a way of distinguising the typical scabby smokebox paint from the boiler cladding.
• Ashes and char on the front footplate will need to be represented.
• Spillage around sand box fillers and oil fillers.
• Water streaking down boiler and firebox, both rain water streaks and hard water deposits. And that'll be best done without the handrails in place. So handrails will need to be fitted, painted, and weathered almost at the end.
• The build up of oil and dirt around the valve gear can be visually significant on a filthy loco, so that'll require some subtle texture.
• Road dirt and brake block dust on chassis and wheels. Radial streaking on the wheels and balance weights. In particular the bloom of rust around the front of the cylinders from the mixture of water and steel grind off the pony truck tyres and track.
• Corrosion and build up of coal dust in the tender coal space.
• Coal load in tender. How much? Just off shed or partly empty? Classic hand hewn lump and slab coal, or, more likely, a heap of late BR calorific dross?
• Corrosion and residual water around the tender filler and breathers.
• Buffer beams not bright red! More of a strong faded pink. And of course, no shiny buffers!
• Overall layer of soot, grit, oil and road dust.
• How to capture that yellowy, oil glazed appearance of steel motion? With oil streaks in the right places. I think there's something on this in the Martyn Welch book.

In order not to get lost in this process and to avoid me randomly daubing and sloshing, it'll have to be written out as a plan. Sequence, materials, techniques etc... This is starting to feel like hard work.

 

Here's my attempt at making a paint drying box. The objective is to place the painted model in a space where it'll dry without collecting dust. Need to keep dust out, allow air to circulate, and raise the temperature a little to speed up curing of the paint.

1. The device is made from two cheap plastic storage boxes from B&Q. The base here is one box with a heater and a filtered air inlet. The heater is a scrounged electronics enclosure heater. It's 230V and 20W, effectively a wire wound resistor in a metal box. It was rather dusty but was easy to take apart and clean up. I don't know what surface temperature it'll get to, so It's mounted on a rectangle of ply screwed to the base of the box. The flex comes in through a close fitting grommet in the side of the box.
2. There's a hole in the box opposite the heater and that's covered by an air filter. The boxes are labelled as polypropylene, but they're surprisingly brittle for PP. I guess plasticiser costs money, and that's why they're so cheap (about £2.50 each I think!
3. The two lids have most of the top surface cut out, leaving a flange to which a piece of steel mesh is glued to form a drying platform. The lids are then glued together top to top. All of the gluing is done with a clear silicone sealant which seems to be able to stick anything to anything.
4. Same as 3 really!
5. The top is the other box inverted. A hole was made in the top surface and an air filter glued over it. The air filter is a cheap automotive filter (about £5 on Amazon). It was cut in half and used for the base air inlet and the top air exit. I originally thought I'd find a couple of suitable vacuum cleaner filters, but it turns out you can buy a lot more filtration for a lot less money if you choose an automotive air filter. A decent fillet of sealant was smeared around the edge of the filters to make sure there was no sneak past for dusty air.
6. Inside view of the top. You can see the round air exit hole beneath the filter.
7. The drying platform sits on the bottom box.
8. The top sits on the drying platform. The idea is that air is drawn in through the filter in the base, heated and mixed a bit in the lower box, and rises through the mesh and around the painted model. The warm air exits slowly through the filter in the top. Well that's the plan, and physics is generally reliable round here.

A bit Larry Lightbulb, but I think it'll work. First test shows that 20W achieves a temperature inside the box of about 5C above ambient. I probably want a slightly higher temperature than that, but not so high that it'll encourage plastic models to warp. That's one reason why I didn't just use a lightbulb, I don't want radiant heat on the models. One other necessary improvement will be to find some low density foam to make gaskets to properly seal the boxes to the lids. By design there's a small air gap between box and lid that'll let in unfiltered air.

I'd be surprised if something similar hadn't been done before, but I couldn't find anything on google.