That elusive Mink…..

By Tony Richards

Of all of the GWR’s telegraphic codes, possibly ‘Toad’ and ‘Mink’ were the most iconic and immediately recognisable. The ‘Mink’ was, of course, the name given by the GWR for a covered van. Invariably a four-wheeler [but not in this case] and built in tens of thousands [five thousand V6 Iron Minks alone, for eg] and a generic name for a number of different types and sizes, the Minks survived well into British Railways days and bodies continue to be occasionally seen dotted around the countryside in use as feed-stores, animal shelters and in other farm use. Age and the weather means that they are declining fast however….

A tiny number, just seven, were built as bogie Minks. These were classified as Mink F and were built in two batches between 1902 and 1912. Their limited number and the fact that they generally ran at night made photographs of them rare and no photographs of them in use appear to exist. All steel in construction, they weighed 30 tons, were 36ft. long and the first two were built unfitted [although later converted]. Running, in the main, between Paddington, Bristol, Cardiff and Fishguard, two survived in stores use into the ‘50s before this interesting class was consigned to the dust of railway history.

The image above is taken from a 1949 Roche outline drawing of the Mink F and gives general dimensions. It was a helpful reference point during this build although this, and the kit’s instruction sheet, contained some dimensional inaccuracies.

And the the kit. This is a ‘Hobbytime’ Mink F. These are expensive and moderately scarce models and have been out of production for a long time. Occasional eBay listings have sometimes sold between £60 and £70 and were, I decided, out of reach. In the end however, I bit the bullet and bought one for £50 on a railway Facebook forum. The kit is a mixture of aluminium and white-metal and not an overnight build. A number of accounts on RMWeb have dealt with the problems of trying to glue white metal to aluminium, with many accounts of super-glued or epoxied models simply falling apart as the glue unstuck. Devcon appears to be the most advised sticky stuff, so I've ordered some. ‘Hobbytime’ was the home of BSL coach kits, also aluminium shelled models. The Mink was their only foray into freight stock and here's what you get out of the box.

I made a start by checking out the measurements for the thing. There is a huge amount of strapping to attach to the sides and the roof as well as door frames to fit and the underframe needs to be detailed in the correct places. I have referred to the instructions but the measurements, as noted, are not wholly correct. I have also referred to the Roche drawing. The measurements there are a little off, also, but between the two and some photographs I have been able to make sense of exactly what goes where and, if all goes to plan, will be just .03mm off overall! I’m not holding my breath however….

I think that the best way to commence will be to assemble the body shell around the floor, spray it with primer and then scribe out the attachment points for all of the fittings. As mentioned, an old post on RMWeb warned several times that adhesives do not take well to the aluminium in this kit. So, I will use a strong epoxy and superglues where necessary. But the first thing to do will be polishing the external sides with increasingly finer grades of polishing paper to scrupulously clean off any oxidation before painting with primer.

I’ve noticed that there is also only one way to attach the roof to the body, glue along the top of the sides. I haven’t bothered to measure them but I doubt if they are even 1mm thick. The instructions advise that after doing this, the model should be rested upside down so that the glue flows down onto the underside of the roof rather than down the insides towards the floor! This seems messy, rather hit-and-miss and there is every likelihood that the glue will spill out visibly down both sides. I’m thinking about fitting some tabs inside the body to rest the roof on to assist in gluing. But that’s a little way off.

I'm almost too ashamed to show the photo opposite, it being such a dreadful mess. But in my defence, the mixing syringe which the ‘Devcon’ came in practically exploded when I applied pressure to the plungers. It dumped twice as much glue inside the model as was required and I had to work very quickly indeed. Nevertheless, the body shell is complete and curing nicely. I was also impressed by the clever method of construction: glue the ends around the floor, insert the bulkheads inside the ends but on the floor and then glue in the centre side sections against the bulkheads. Everything fitted perfectly and, thankfully, no epoxy leaked out anywhere. I'll give the outside a further rub down tomorrow, before fitting the roof. The excess glue inside doesn't really matter, it'll never be seen and certainly ensures that everything should stay in place. It's just not neat however, and that annoys me.

Whilst the body was curing, I replaced the kit’s wheels with more modern pint-point three hole 3ft 1inch Gibsons.

I’ve mentioned that the instruction sheet advice to glue the roof in place by slathering [my word] epoxy on the inner tops of the sides and ends and then inverting the body over the roof, securing it with rubber bands, and leaving it to cure upside down was inviting trouble. There could be no guarantee that the epoxy would be fluid enough to flow downwards to sufficiently cover the roof to hold it in place. The Devcon, as self-mixed, was simply too viscous and the sides far too thin [actually .55mm] to take superglue.

I decided in the end to cut 4 bulkheads from 3mm dense foam board, using the inner curve of the roof as a template, and glue them to the ends and inner spacers. They were fitted over-proud and the roof gently dry-fitted to push them down to the correct level. I'll be able to epoxy the roof in place now.

But first, I'm now ignoring the order of build and will be fitting the buffer beams, solebars, door fames and side-strapping before the roof. The body has been scribed up for the strapping and that'll probably be done next.

You can see in the next photo that the strapping and door frames for the first side have been attached. Superglue did not adhere as instantly as Devon but the thinness of the pieces required just a smear and so something far less viscous than epoxy had to be used. It seems to have cured pretty well now and, hopefully, primer, two top coats and then varnish will act as a further retainer.

Folding the fragile and thin rivetted strips to fit into the solebar undercut was tricky and required a simple jig to make the folds. It was 95% successful and, again, I think paint will do the rest.

Altogether not unenjoyable so far. I'm dying to get a coat of primer on it, but the other sides and the ends must be completed first. You can see that the buffer beams and solebars have also been applied.

All of the vertical strapping has now been completed and the ventilators fitted to the ends. I need to attach horizontal riveted strapping to the bottom sides of the van but, being a little unhappy with what was supplied, have ordered some etched brass replacement. In the mean time, I decided to attack the queen posts [literally] and fit the truss rodding. One can be seen resting on the vernier in the photo.

The instructions are poor here and advise drilling a .7mm hole through the ends of each of the posts to receive the wire supplied with the kit. One look made it obvious that this wouldn't work: a .7mm hole was far too wide for the .9mm posts and the wire was .8mm in any case. I drilled a pilot through each at .3mm, widening it to .5mm and then threaded .4mm brass wire through. That worked fine and did not destroy the posts as would have happened had I followed the instructions.. I did break my only .3mm drill though! This was not the first of a few necessary diversions from the instructions.

Another problem has arisen with regard to the bogie bolsters: they cannot be adequately fitted as described. The V-hangers for the brake gear are a bit dodgy, too! I'll update with the solutions and further photos later. This remains a thoroughly enjoyable build however.

The truss rods have now been glued into the queen posts [already glued at the back of the solebar]. They are completely symmetrical, happily, but I cannot but help feel that the queen posts are just too long. It might just be an illusion and no measurements were given in the instructions. There's little I can do about it now and painting will improve matters anyway.

The bolsters for the bogies have had to be screwed into the underside as the instruction to glue them flat wasn't going to work: the outer edges of the floor along the underside are higher than the centre, a consequence of the way in which the solebar pressings were made. I had to epoxy the bogie retaining bolt in place, too, as it would not sit tight against the floor. None of this matters in terms of running however, just a bit of poor design.

I also felt that the gap between the top of the bogie and the body was too great, too much daylight was visible. A simple solution for this involved filing the slightly curved horizontal rubbing strakes off the tops of the bogie frames and replacing them with strips of .25mm plastic strip. This is smoother and less prone to friction than white-metal to white-metal would have been. Photo shows it all.

A dry fit with the roof. The strapping does not look so overscale in reality as it does on here. It does show the rugged appearance of the prototype quite well though. I have also fitted some replacement etched brass strapping around the bottom edges of the body as I felt the original supplied with the kit was too heavy.

The bogies that came with the kit have now been constructed. I say 'constructing' when 'simply sticking together' should have been the order of the day. As it was, the bogies, which comprise just three parts each, were too narrow for the wheels that came with the kit and without some work I had no chance fitting brass bearings and the new Gibson pin-points. Some careful packing helped to widen the sides however and a lot of filing allowed for further manipulation. Left for the superglue to thoroughly harden off overnight, all was well and they are extremely free-running and quite solid.

I took the beast into the club to check its running quality. I fitted a temporary coupling and tried it on various layouts. It ran without a wobble, very smoothly in fact, and had no problem with tricky track geometry either. So, bogies back off next for more permanent couplings to be fixed [and a method for doing this to be devised] and the brake gear to be installed [with cosmetic pull rods]. It's off to the paint shop then.

The photo below show the Mink with its roof blutacked in place temporarily to check fit. A little manipulation will be required for the final fit with epoxy. Its size against a Pannier shows just how large these things were.

The brake rigging has been fitted and the body is now in primer [which, as always, covers all of the sanding scuffs and other scratches beautifully]. The original V-hangers were heavily cast white metal things that just didn't look right. I have replaced them with brass etches instead. I have also adapted the bogies to take their permanent couplings (not shown). Ignore the dust and stray hair!

With all parts now either in primer or fitted it was time to apply the final livery, letter the body and complete the build. The paint used was Railmatch GWR Freight Grey [two coats], the buffers and draw hooks were painted matt black, the decals used were a mixture of Railtec and Pressfix and the body was then given a final coat of satin varnish to seal everything. The bogies were then bolted in place and the bolts sealed with thread-lock. The photo below shows the underside with the various brake-pulls picked out in rust just to make them a little more visible.

And finally, some shots of the finished model……

So, was this build as difficult as some on-line accounts maintain? Well, no, not at all. It is fiddley, certainly, and needs some work-arounds but it was a relatively straightforward and hugely enjoyable project and one that repaid the not insignificant cost of its purchase. It’s also pretty unique and I think it’ll be a long while before I see another one running!