Atlantic's works: Portable layout - Scenic details next

[Manxman1831]

If you are in a position to do so, I'll take on of the new mould W1's come the new year. Will wait until then to confirm, as it saves getting lost with the usual post at this time of year, if you don't mind.

[Atlantic 3279]

Just let me know in the New Year when you are ready to go.

[Atlantic 3279]

Fancying a break from repetitive casting of resin carriage seats in unexpectedly large quantities, today I've made a little more overdue progress with the sides that I hope to turn into an ECJS D.30 pantry third, or the equivalent GN diagram. I'd previously decided that they weren't quite straight enough as first assembled, looking in end-on view like the sides a vehicle with severely over-tightened truss rods. They proved resistant to straightening in hot water owing, I presume, to their relative height, so I split the lower parts of some of the joints with a razor saw and slipped in some packing pieces to do the trick. After filling and smoothing again I could then turn to reinstating any damaged beading and adding other parts of the beading that needed to be there. Some delicate work with white microstrip, well stuck down with solvent and its edges then trimmed and shaped a little with a small scraper, gave me this:

A little paint mixed to a similar colour hides the smoothed joints in the panels and allows the added beading to be judged for its likely final "match" to what was already there:

I might make a mould that allows duplication of these sides before they get incorporated permanently into a model, if I really feel like devoting the time to that task. I also have some ideas for an alternative, more adaptable version of the clerestory roof casting, but it all takes time to do when there are so many other things I'd like to get on with too........

[Atlantic 3279]

I find myself in an usually good mood on this Friday 13th. There must be more to it than a lack of rain and a bright sky for a change.....

Anyway, some views of progress with a trial assembly of the D.30 pantry third parts. Sides and ends are joined only with tiny dots of cyano acrylate at present, to allow separation for possible later mould making from these "master" sides.

End of the floor, which comprises two layers of 30 thou plastic, the top one of full floor width, the lower one matching the width over the solebars which are formed from 3mm Z sections. The stepboards will be added on top of the projecting lower ledge of each Z later. At this stage the solebars ends are left long, so that the body ends sit on them, raised a little by a cross strip of 20 thou plastic. The buffer beam can be built up to shape and the solebar ends trimmed back later.

Using ends with a formed concave inner face on the D.79 proved quite tedious and in my view un-necessary, so in this case I cast the ends with flat backs. Onto the backs, I simply stuck a layer of 40 thou plastic of the size and shape that would form the necessary rebate at each edge to accept the end of the side - in this case a door. The added plastic layer is kept clear of the bottom edge of the end (so that it doesn't conflict with the floor), also stopping below the "top of side" level so that a flat ceiling can be accommodated right up to the end if necessary. The top of the flat back of the end is chamfered (by hand) ready to accept the projecting end of the roof.

Note that (as on the D.79) drawings and study of the very few photos seems to confirm that the outer face of each door was inset relative to the widt of the end, as well as with respect to the side. It also looks as if the visible portion of the cantrail above each door was recessed too, although the cornice / gutter above it (to be added as the edge of bottom layer of the ceiling / roof structure) was straight.

The bogies that are already in place are currently the modified 247 Developments ones that I originally made up for possible use on the D.79, prior to Mike Trice and Dave Sutton coming up with a more exotic option. A short piece of 4 x 4mm square section plastic stuck width-ways below the floor carries the bogie pivot pin and gives a nice ride height.

[Atlantic 3279]

With much of the house occupied by family and by Christmas decorations at present there's no scope for making an improved roof master, a new mould, or resin castings on a serious scale, so I've left further work on the pantry-third in abeyance and started an overdue test build of some etches for a GC self-trimming tender. I can just about do that working on a small piece of board with minimal hand tools and a small soldering iron, all of which can be tidied away in a matter of minutes when other tasks assume priority:

[Horsetan]

....started an overdue test build of some etches for a GC self-trimming tender....
022 tank with top, loose trial fit.JPG

Excellent!

[Atlantic 3279]

Rather more of the tender is now in evidence, most of it fully soldered in place rather than just standing loose to check the fit as the main tank body was in the previous picture. I won't pretend that I haven't had to make any adjustments to the test-etch parts, some edges have had to be trimmed (but not be more than half a mil at the most), four missed fold lines have had to be scribed in, and I haven't quite managed to get the flares / cornices to mitre together at the top rear corners, but even as it is now the etch would be perfectly buildable by a modeller who proceeds with caution or who heeds instructions produced by a previous successful builder. I had been given the impression that the hopper bunker might not fold together as it should and fit the rest of the structure correctly - but the way I've done things it does fit...

[john coffin]

Thinking about things Graeme, please don't fill the two holes in the rear of the tank top,
they are actually drain holes on the prototype!!!!!

Looks very good thanks for the work.

Paul

[Atlantic 3279]

I intended to show a little more progress with the ECJS pantry third two weeks ago, but Christmas got in the way....

Using a scrap resin casting for a clerestory roof, I investigated some alternative approaches to the problem of portraying a bespoke layout of windows, having greatly disliked the chore of altering most of the apertures and then flush glazing them individually in the roof of the previous D.79 carriage. Given that (even when they hadn't been panelled over, as some evidently were in later days) the windows seem generally to have been etched / frosted and possibly downright grimy rather than crystal clear when the vehicles were in service, simulated windows rather than real ones seemed to be worth a try. I firstly had to get back to a smooth flat side on the cast clerestory, in place of its generic layout of apertures. The roof projects only very slightly beyond the sides of the casting, so any attempt to cover the apertures would have to use very thin sheet material.

I tried 0.005" styrene, after making sure that there were no raised imperfections on the existing cast side, but as I fully expected, even cautious use of my favoured solvent made the plastic wrinkle. Had I used any less I don't think it would have stuck, and the idea of using a milder solvent such as limonene did not appeal as I've had thin sheet detach at a later date after using only limonene to bond it to a dissimilar material.

I also tried some 0.003" shim brass, attached with glue, but the waves / ripples in its outer surface demonstrate that the cast side wasn't quite so flat and true as I had hoped.

Faced with the apparent need to smooth the side down more thoroughly before bonding any new surface layer to it, I decided that I might as well just leave the film of casting flash over the backs of the apertures and fill them up with car body filler, then smooth the lot down and paint that surface direct with a suitable shade of grey gloss. I then ruled on some new "framing" using teak-coloured paint in my bow pen.

I think I may be able to find a better shade of grey if I experiment further. The photographs have failed to show the glossy / glassy surface of the mock windows, but it is evident to the eye.

The real idea is to make a new mould that produces the castings with smooth flat sides ready for decoration with false windows.

A look at the trial piece on the carriage body, lifted by a couple of pieces of 0.030" plastic - the same thickness will be needed to represent the cornice / gutter when the roof is fitted properly.

I had also done the basics to the underframe before the festive break.

[Atlantic 3279]

By the way, I did also start looking at the idea of casting the clerestory roof in clear resin, but in view of my total lack of experience with clear resins I was deterred by a number of things. Firstly I couldn't find an easy, small quantity, on-line purchase option for a clearly identified resin for which I could find a data sheet, because I would have to be certain of negligible shrinkage during the curing process. Secondly, the clear resins I was finding seemed either to be "stinky" polyester, which I might not be able to use in the house, or a type of epoxy with a well-emphasized need for an extremely accurate mixing ratio. Not being at all inclined to mess about with extra equipment such as digital scientific weighing scales I wasn't sure whether I could get away with my careful volumetric technique which always seems to work with "ratio sensitive" RTV mould rubber.

If anybody has certain knowledge of a no-stink, no-shrink, mix-ratio-tolerant, clear rigid resin that can be bought easily in small quantities I'd be interested to know please.

[earlswood nob]

Good morning all

One cab get "crystal clear" resin for use in jewellery, so must be available in small amounts. I imagine as it's used in jewellery, it's really clear.

I do not know if it fits your other requests.

Malcolm (aka Earlswood Nob)

[Atlantic 3279]

I've moved a little further on with the GC self-trimming tender. Noticing that the control handles and their supporting oval bases that sit on the raised structures either side of the main tool box were certainly small and fiddly in any case, then also finding that there were some snags with the dimensions of the larger parts that would require modifications, I decided that I should make up the "tool-box group" structure as a separate module then add it to the tender. That ended up taking most of an afternoon, so perhaps I did not apply my skills in the best way. In order to fit the module as I felt it should be fitted, I've had to additionally make provision for the front coal plate to sit a little further back than it originally did. That plate now has its top-edge beading fitted, and I have at last made my mind up about the way to fit the upright rear coal plate, which is now fitted too.

[Dave]

Looking good Graeme, but I expect a lot more detail from you and working bits as you are working in a much bigger scale than the esteemed Tim Watsons
little N gauge GCR tender................

[Atlantic 3279]

Hello Dave,

I presume this means that your alimentary canal is now functioning correctly.

What would you have me fit? Flip-up filler hatch? Working brakes? Working water scoop with prototypical linkages, those on top available for inspection on lifting the covers on their housings? Operating sanding gear? Fully functional water cocks and flexible hoses?

I am more than happy to admire the superior, exquisite results of the top modellers in 2FS while I stick to producing something "adequate" in the easier, most popular, most commercially supported scale.

[jwealleans]

If Dave keeps referring to Tim’s work as ‘N gauge’, one or other of his canals may be in jeopardy.....