Grovenor Sidings, Railway Modelling Pages by Keith Norgrove
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Updated: 07 November 2004

Cast metal Kits

A series giving the "knowledge" for successful construction

R. C. Ormiston-Chant

This series in 5 parts was originally published in 5 parts in the Model Railway Constructor from February to June in 1972 (I think that was the year), Robbo was a stalwart of the Manchester Model Railway Society and well known in the letters pages of the magazines for a long period. I'm sure he would be happy that his article remains available.  KN.

CAST metal kits, made by a process of centrifugally casting parts in a soft metal having a low melting point, have been with us for a long time now. Nucro once made some wagon kits, now somewhat treasured, for a short time, but it was the dark deed of Ken Keyser in 1956 that really set the ball rolling. Furtively he threw at a derisive public the first kit for the GWR 4800, later 1400, Class 0-4-2T locomotive, the kit being to 4mm scale. From then on he was a made man and soon to be imitated by Bob Wills. BEC of Tooting followed with more locomotives particularly in 3mm scale and later returned to the road with tramcar kits though trains clang and do not toot. George Mellor eventually joined in by making the LNWR his particular preserve, both in 3 and 4mm scales; he has also most successfully modelled the other worthwhile railways, the GWR, MR and CR etc. Other firms have indulged, often in other fields, while Peco have produced loco kits for N gauge, Anbrico and Brackenborough are devoted to the road, the former excelling in exquisite kits for buses ancient and modern. Yet again some firms have used these cast parts in a secondary role as may be seen in the PC Coach Kits and one way or another the process is well entrenched as a sound, accurate and reliable means of producing small castings in either small or large quantities.

My own regret is really that there is not an adequate range of minor fittings and mountings done in the metal, many parts do exist often as corollaries from a complete kit pattern, K's and GEM will offer any part this way though most unfortunately Wills cannot for certain reasons, a pity as he goes in for some interesting items and casts to very fine limits with a highly developed machine. If the problems attendant upon the use of multi-cavity dies (producing a number of different parts per cast) could be solved I feel that modellers would be encouraged to adventure a little into the scratchbuilt world using these cast parts, often of standard components, for the troublesome things beyond the skill of the novice, or even experienced, chap.

However, Bob Wills pointed out to me that while he makes some 32 kits these yield almost 50 locomotives without radical alteration, for example, the kit for the GWR "Hall" can be readily altered to give No 4900 or the "typical" Hall, or the final development with through frames. And the LNER K3 2-6-0 gives two versions, GNR and LNER simply by altering the cab and one or two minor details with a more major operation on the tender. Some of his kits are planned with this in mind, such as the SR Mogul" or the CR Shunting Loco. A brief scan of the W&H Catalogue shows that there are 110 types of locomotive alone available in all scales from 2mm up to 4mm including variations built into the actual kits. Add one's own variants and one has a lot of motive power. "And still they ask for more," I quote Bob Wills.

Apart from motive power there is a good family of rolling stock along with such diversities as signals, water cranes and hand cranes for goods yards. The list is formidable when worked out in detail.  While I came to cast kits quite late on, only about 10 years ago, I have so far turned out over 50 locomotives and several other items including trains which I dislike and George Mellor's Yard Crane which I adore, likewise the vintage buses by Anbrico. 

Some techniques still elude the makers. The kits are produced by making dies from a Master Pattern, and hot metal is then run into the dies by centrifugal force. A one-piece boiler casting so far eludes the hobby except for Wills tiny SECR 0-6-0T, and the same maker had to finally cast the sides of the LNER A4 Pacific in four pieces before it came out right, but on the whole almost everything In the railway field could be cast if it was economic to do so.

Unlike the Editor I have never punched a hole in a kit during soldering though I use this means almost exclusively down to the tiniest part, but then I could believe anything of our worthy Editor! As you gaze across the murky wastes of an exhibition your eyes alight upon him and you exclaim "There is a man who melts a hole 78 thou diameter in the third cabside of a Ruritannische Statsbahn 0-7-2T ! ". As he edits this we had better proceed to more useful data. [Well, we can all makes mistakes!—Ed.]  I am human and in early days I did vaporise a whistle or two, but being human and of a thinking mind I thought it out, my solution will be described. So, good friends, let me point the way to Nirvana while you all make off hastily in the other direction.

Before I ascend Olympus (mountain, not jet engine), I will point to some risks. They are NOT to be taken lightly, they may be small but they are there. The metal used in the kits is poisonous, the solder and adhesives are no less so, some of the adhesives are downright dangerous in an enclosed space. Therefore (no matter how in convenient it may be): when using adhesives giving off a flammable vapour have enough ventilation about the room. If your skin is sensitive use a barrier cream on your hands. Before you ever touch moist food always wash your hands thoroughly to free them of filings and other swarf of the metal. The odd cup of tea or biscuit may not pick up the dust but a nice moist tomato sandwich will do so and the consequences be unpleasant and serious. So wash and wash again in hot, soapy water. The special flux used in soldering is harmless though it is an acid, but it can make you sneeze if you inhale its hot vapour through your nose. As the soldering iron will hit you during the uproar you should treat for burns as well as asphyxia! (I am told that phosphates are good for the nerves, I really wonder so during battles with difficult kits!)

Surprisingly enough while the soldering technique may seem rather harrowing (see later), the risk of scalding is very small, if the job is that hot you are heading for a melted kit, so there is a built-in warning for you. If young children are about the house keep all chemicals out of their reach, but as toddlers and fine models do not mix, parents will have their own routines here.

Ways and means
There are three ways of getting a kit together, you will gather that I am sold on soldering, indeed the purpose of this essay is to detail its technique fully. But, the kits may be assembled by adhesives, or by "fusing", or by soldering. "Fusing can be dismissed now. It means that the locating bars of the adjoining parts are very quickly melted together with a large hot iron, a sort of Flash Butt Welding process. The method is ONLY suitable for big parts having the bars, and requires considerable deftness and skill. I do not recommend it but mention it to reassure those who practise it and like it.

When I first began I took one maker at his word and glued the parts together. Though I used the best Scotch Glue and even our dear friend "Seccotine" I made no progress because the glues will not bond on to the metal. Therefore, one should for once disregard the maker's instruction sheet, and NOT try to glue the parts together.

So I turned to adhesives. There are a large number of these falling into three broad fields, the Epoxy Resins, the Petroleum Base Cements, and the Cyano Acrylates. Of the first, Araldite is long established and a very good "goo" though there are now some that will cure at room heat fairly quickly, but they are quite costly and not common, an exception is Isopon which I have not used myself but understand to be good. The Petroleum Cements have the most popular appeal, being easy to use and easy to buy. The best used to be "Pafra", which was a lovely thing free from stringing and most versatile in application, but it has gone alas! Today we have such media as Bostik No 1, Evostik, or UHU, while these string somewhat they are good sound adhesives of general value about a model railway. The first named are both impact adhesives whilst the third is a simple contact adhesive.

Cyano Acrylates are a new concept and while they are not freely available they deserve mention, if only to encourage Douglas Kane Limited to pack them for us modellers. They act by means of the free ions present on the surface of most hard materials and many plastics as well. When air is excluded the cement goes into action usually very quickly, it is immensely strong and proof against all our ills. The most spectacular is the most expensive, Loctite IS 06, this acts in half a second and will really stick solid a host of troublesome things, such as nylon to glass, polyethylene to metal etc. If it were readily marketed in small amounts it would be a third hand in securing parts in line whilst they were finally soldered, something of great value in kit assembly. Its price is very high, about £1 for a 3cc bottle, but as only small spots are used it is in fact a thrifty item. Another Loctite product, Retaining Compound, is for bonding in place bushes or wheels and so on. Thus I use it to fix worms on to motor shafts and wheels on to axles; I never use the grub screws (if any) these days. As one small drop secures any model bush or gear the 3cc bottle goes a very long way for its 9s 0d or so, mine is in fact 2 years old and I use it steadily. But as I remarked before these adhesives are still much an industrial matter, wherein they are tailored to suit the job, and if only the makers would pack them in small tubes, say about 1cc, I am sure they would appeal to the modeller wanting to keep kit parts in line or secure worm wheels on to axles when a force fit would be normally needed yet a difficult thing for the ordinary chap to attain.

Finally we come to solder. This is a special solder designed to suit the kit metal which melts at around 100 deg C. Thus the solder melts slightly below that. Two firms supply it, EAMES and George E. Mellor. One packet from either will do a medium-sized job such as a 2-6-0 or a 2-6-4T, it depends on the finish of the cast parts (see Later). A special flux based on phosphoric acid is required, this also comes from EAMES and from general suppliers in the form of "Soldaflo". there may be other brands unknown to me. Commercial acid of 40 per cent concentration can be used though it leaves an oily waste behind which is annoying. It is by far the best general flux for all of our modelling, being safe for electrical work and free from any corrosion and suitable for all normal soldering metals including stainless steel, for which it is the only tinning flux. As the acid is also a rustproofer, it is the basis of the modern ones, it particularly recommends itself for models using steel or tinplate as it will not cause later corrosion like Bakers Fluid, and will in fact rustproof bare steel or iron surfaces and edges. Moreover, once it is washed down it makes a fine base for painting. However, on the kits, if it is left for any time, it forms a hard, grey powder that stops paint from drying, and you will see that a strict washing routine is needed.

In order of speed, assuming that a kit could be assembled through out with the Loctite, that would win hands down, a couple of seconds for each joint with the least preparation needed, just a scrape clean. In fact, using IS 06 one could do a big loco for about 50p, which is not much, you know! Then comes soldering, which has the great virtue of doing its own crack filling etc. After that the impact and contact adhesives, but which need crack fillers. Finally, Araldite, which must be heat cured in between each sub assembly, though it can be tailored to fill as well.

Techniques for adhesives
For the sake of completeness I am mentioning the Loctite "goo". as, who knows, it may one day arrive for the common man. Each mating face should be trimmed by filing, and wiped clean with a small swab of Acetone, this makes the job certain. (No other solvent will do at all.) Pinhead drops are applied to one part, say every inch of a seam or a couple of spots for a butt such as a footstep. The two parts are brought close and lined up exactly, then put together for a second or two. Brother, you have got to be right first time.

Impact and Contact cements
Each face trimmed by filing and otherwise scraped clean to bright metal. If handled at all, wipe with a swab of Lighter Petrol, the most convenient and cheapest model cleaner. Using a small stick or tool a thin wipe of adhesive is applied over the face of each part where joining. With Impact adhesives allow 15 minutes to dry, then present the two and force firmly together dead in line. With Contact adhesives, apply the thin wipe with a tool or stick and bring the two parts together, hold them thus securely for at least 10 minutes to set. Never just squeeze some goo on to the bits and bung them together, this is the downfall of many good kits.

Epoxy Resins
File and scrape the faces to bright metal, degrease if handled, mix the "goo" and apply a thin but noticeable layer to one face, bring the two together and apart again. If there is full contact restore the mating, if not check why and if necessary clean off one face and file it to fit, then resume routine. Secure the parts firmly in correct alignment and cure the adhesive. With Isopon this will happen at room temperature in about 15 minutes, but after half that time go along the joint with a fine, sharp craft knife and remove any beads or surplus adhesive. With Araldite, the job must be put in a warm place, I find that the top of a convector heater is fine, or else about 18in in front of a radiant heater, or any similar warm but not hot place. Leave for 1 hour at least, cooler places may need twice that After half-time go along with a knife and remove excess. The job will be firm by then but still rather soggy so be careful. If you do not remove excess Epoxy Resin you will have to do so when it has hardened, and I warn you that it knocks seven bells out of small files and is generally difficult to work. (If it can be filed or drilled in the clear it is all right, you can use oil or water to keep the tool clean, but with the odd corners of models this is not so easy. In fact I know of Araldite being used to make castings in 2mm scale very successfully, being drilled and cut with ease after curing.) Araldite may be cold cured but it takes at least 3 days, longer in winter.

Under no circumstances may a cast kit assembly be cured in an oven, this will collapse the assembly by softening the metal. Oven curing is done at 65 deg Centigrade and this is far too close to the metal melting point.

Epoxy Resins may be used to fix parts on after a model has been painted, the contact area being carefully scraped bright. The others cannot be used in this way except by meticulous care as the slightest amount of "goo" straying on to the paint will promptly strip it. As you may thus ruin many hours of patient livery work you should think carefully first.

If you make a 'boob" with the Loctite you may be able to soften it locally by heat and break the joint, be careful though. If you do so with Araldite you have had it. There is a special stripper attacking it but one must leave the whole job for some days in an atmosphere of the stuff, so this is not on. The Petrol Adhesives are easy, apply some ordinary paint stripper such as Polystrippa to the bad joint, wait five minutes and then gently ease the two apart, a small screwdriver may help. Clean off all the muck and remake the joint on to bright metal again.

With Low Melt solder it is even simpler, if you own a Butane Cigarette lighter. You set that apparatus to a high flame, hold the bad joint over it just clear of the tip and keep it moving, up and down the joint, the job will warm up and finally the joint will part. Arrange that gravity lets one part fall away. Immediately remove all heat and cool the parts, clean down to bright metal and resolder. I have stripped most of a complete loco this way though I had to refill the lighter twice! The important thing is not to let the flame dwell but move unceasingly along the joint and around it.

Crack filling
With all the adhesives some filling will be necessary, the Araldite breed can well fill quite a bad gap but not if the parts need to be held in line as well. So a separate operation is indicated and there are quicker ways. The others will not fill properly, if they have been so slobbered on to do so, they are not making a good joint at all. Brummer Wood Stopping is an admirable and very old filler, and I like it. The Editor of another magazine told me that at the end of a competition at a Show two exalted modellers, one an unsuccessful competitor, criticised the judgment on the grounds that the model was painted, so it did not show any foul deeds such as Brummer. The Editor rightly replied that if anyone had the cheek to make a whole model of Brummer and it looked right he deserved the prize. Of course he deserved it! However, some folk may like to use Cellulose Putty, I like it too, and it saves time in that it dries fast and needs no sealing before painting. Plastic Kit folk are much addicted to it for "customising", as they call it. However, do not paint it all over for a couple of days as the vapours inside must bleed through the hard skin that forms within seconds, these vapours will ruin any fine paintings, as they emerge. Low Melt Solder needs no crack filling as will be seen later. It is well to make one's own little tools and applicators both for filling and applying adhesive; they can be tailored up from tinplate or 270 Micron sheet stock.

After treatment
I am not at all qualified to advise about painting, other folk are better fitted than myself. But with kit metal there is one precaution to observe. It is very porous and slightly basic in nature, thus it does not hold paint too well and just will not hold fiat paints at all. Hence one sees so many kits on layouts whereon the edges of running plates etc gleam brightly where the paint has rubbed off.

I cannot trace any suitable etchant for the metal, neither Chromate nor Plumbate are at all suitable, being intended for cupreous or ferrous metals in that order. In fact I found by experiment that Chromate flakes off if a model expands slightly with warmth. A lead ing paint maker told me that I was wrong so that was that! He advised what has since many times proved the ideal way.

Wash the model in a degreasant. Here Lighter Petrol is a cheap and very safe and efficient medium to use, it will not attack plastics or the varnish on motor windings etc, so it is safe to bath a complete loco in the stuff to clean it and I have done this many times. (However, be careful with toys such as Tri-ang, you may dissolve the lining etc which is a Spirit paint of some sort, just wash the mechanism only.)

When the model is dry again, slightly thin down a good plastic enamel (GLOSS) such as Humbrol or Joy, or a Lacquer such as Valspar. Apply a free but not excessive coat over the model. Allow two days to dry and harden. You will then see that in many places the paint has soaked into the model surfaces, in so doing it has sealed them all with a good fine coat of neutral plastic, just right for the railway enamels. Compatibility is at a maximum and the surfaces are free from further absorption. Naturally one chooses a colour sympathetic to the final livery, bearing in mind that black laid on after will obscure anything, so you can paint the entire model, inside and out, green or crimson or whatever. In fact, my sealers are:
   GWR, Early SR and similar dark greens—Humbrol Brunswick (3). 
   LMSR Crimson, NSR etc—Humbrol Crimson (20).
   LNER, Late SR, LSWR etc—Humbrol Emerald (20)
   Blues. GER etc—Humbrol Midnight (15). (Note the dark colour.) 
   Black Humbrol (21). (Note the dark colour.)
I thin by about 10 per cent and brush so it JUST lies on without dribbling.

This leaves only Soldering to come, and I have a feeling that there is an impatient queue waiting. But even so, try the other ways, say on Ken Keyser's wagons, because you will learn a lot by them if you sample each, and the wagons will not take too long, also they will survive a rough job as they are not prime movers.

Low melt soldering
Just to madden you all I will delay a bit longer to expound on this stuff. It is intended for the bonding by joining of the metal used in making cast kits. As it stands it is NOT suitable for other metals. But it will give a reasonable hold to all normal soft soldering metals if they are first finely tinned with common solder. Thus it becomes quite easy to make substantial alterations to a kit as supplied even if, as is likely, sheet stock of kit metal is not to be had. For example, one may, in making up George Mellor's angelic little LNWR Crested Goods 0-6-0, fit tender cabs as was done on certain of the machines used in the Lake District, but these also had Belpaire fireboxes ... and so we go on. Thus, one should make up the sub-assembly of say tinplate (cheaper and more plentiful than Nickel Silver these days), and after ensuring that the final matings are carefully tinned one may solder the assembly to the completed or partly completed kit, using low melt solder. Very small matings such as machined handrail pillars (knobs) do not like this much, hence I prefer split pins for such items on kit models. See later. I emphasise that the hard metal unit must be a complete job, if one wants proper sheet deflectors on one's SR Mogul instead of the thick cast ones, one must make up each deflector with its beading etc, and then solder the unit in place. But again see later how I do that job. Given an adequate mating surface low melt solder will hold hard metal parts quite well so long as they are carefully tinned first. Now for the 'meaty" part.

With normal tinning solder one gets clean surfaces and applies flux to keep them so under heat. One then heats up both parts adjoining and runs in a line of solder which makes a molecular lock on to each part just at the joint.

Low melt solder does not work quite that way. One cleans the two surfaces, reasonably so anyway, the flux will take care of all but sheer filth or the dried-up deposits from old flux (note the last). One floods, repeat floods, the joint with flux and presents the edge of a bit holding the solder to it. The heat of the bit boils the flux which then melts a tiny amount of the kit metal on each face and the low melt solder runs off the bit into this wee puddle to form in effect a Fillet Weld.

I discovered this when many years ago I misplaced a chimney or something and duly "flamed" it off with my lighter. I then saw that where I had soldered the piece there was a little ring indented into the parent assembly, where the kit metal had puddled, so I realised that a proper weld had taken place. After that I frankly exploited the phenomenon mercilessly and still do so, but it requires some hours of practice to tinker about in this manner.

A Wills kit of the LNER class N1 0-6-2T awaiting finishing touches, shown against a drawing and a good photograph of the prototype—, both essentials for a good model.

Just bear in mind that when you use low melt solder on a joint in kit metal you are making a proper little fusion weld. This is why the method is not so hot with hard metals, a full weld does not, of course, occur. It also explains why normal tinning solder is not suitable for kits, if a proper bond was made the kit parts would be melted wholesale and destroyed. The flux is the worker here, as by boiling it melts the kit metal and at the time draws the solder off the iron into the joint to fill it. So may the canny modeller fill all cracks, even whoppers. I have backed up a gap of 1/16in with strip wood and filled it with low melt solder when I did not have any kit scrap to make a packing piece.

It is well to try out the process on some old stuff before you first jump in so that you get the feel of it. Therefore, choose a kit that offers alternative parts and use the unwanted ones as test pieces. Having made your first ever joint on a suitable object, clamp it hard in the vice and try and wrench the attached part off with pliers. If a union of about 1/8in square is sound you will have a real job on. If, however, the bond is not properly made the two will come away very easily indeed, so you will be in no doubt as to your success or failure.

Now try a bit of crack filling. Choose two pieces that offer a nice gap when joined. Put the smaller edge to the larger and place some flux, put on at one end of the seam a small blob of low melt. If you are satisfied with alignment, go to the other end of the seam and having flooded the lot with flux take up a good iron full of low melt solder and work it slowly along the seam, until you reach the first blob. When you hit that the other end should be cold, this way the two parts are always supported in line by hardened solder. Now reflux on the other side of the joint, and run the iron along slowly, letting the placed solder gradually melt through until it shows a bright line. If you want a good supporting fillet where it will not show, you can instead feed more solder in to make one. This is of great value in supporting things like footsteps from the back. (If possible in such cases I like to put in a wee gusset of scrap kit metal, it saves a model coming back after a week minus its steps.) After a little practice you will find the art of 'teasing" the solder through a seam to make a really neat and trim joint that needs no further attention, in this respect there is a massive advantage over normal solder which cannot easily be managed in this way. To put a long tankside to a running plate and finish with a perfect corner joint is very satisfying and usually done at about 2in a minute inclusive of preparation, you cannot do better than that! Troublesome boiler joints cease to exist, as they are deftly overlaid with solder much as a welder builds up over one of his joints, the excess then being filed back to profile (known in full-size welding as Flush Grinding).

The last exercise is a really shaggy one, the soldering of the whistles (etc). Some folk like to put on brass whistles like the real things and ditch the kit ones, but as whistles never did show 'brass', not for long anyway, there seems little point in this.

In your long suffering test piece, drill a hole for the whistle. Countersink this hole till it shows about twice the diameter. Flux it and quickly wipe round it a small bead of low melt solder, about a pinhead or so in size. Pop the whistle in place, easing the hole if need be, and flux again. Now put the flat of the iron near the whistle on the parent surface, NOT touching the whistle. In a second or two the flux will boil, the solder around the whistle will melt and flow in to meet it. Remove iron. So long as you do not hang around too long, particularly after boiling ceases, the whistle will not melt fully. only slightly in the hole. It will be secure, and probably broken off during the first week's service, so back to brass ones!

I said the above was the last exercise but you might as well fix a handrail pillar. Thus your test piece ought to be thin, I have in mind the alternative boiler shells supplied by Wills in certain kits such as the Caley 0-6-0T (which is the ideal beginner's model anyway, and a charmer for any layout). We can use a split pin as it stands for the test so simply pop it in the hole, and spread out the tails underneath. Scrape a little each side of the tails and put on some flux, not much. Take up a good blob on the iron and drop it across the split of the tails so it flows each side and forms a bridge across the split. Thus when the pillar is normally standing proud of the boiler casing it cannot be pressed back into it accidentally, if the little bridge is sound. It is no use trying to just solder the tails down, the low melt solder will not hold on the split pin copper plating, you must actually make a bridge across the pin. Also I emphasise that the tails must lie flat inside the boiler shell.

This summarises the basic technique of using low melt solder. If the above routines are tried on one spare part only, the average chap will gain experience to take on the model proper, and he can, of course, undo the job and remake it to his heart's content without worrying about the eventual results to the test piece. That may be either framed as a precious relic or best of all crushed in the vice and used to ballast a plastic wagon or something. Some kits offer so many spare parts that one collects an army of "useful things". I have built a dozen GEM LNWR 4-4-0s and thus acquired 24 spare tender buffer beams and numerous "Precursor" splashers, which last are very useful as stocks for other large splashers! My fellow GWR men will be horrified to learn that six ended up on a hard metal "Hall" class loco, they were just right when cut down! Another 6 were given to a friend to make his Wills SR Mogul take 6 ft scale wheels. I will draw a veil over the possibilities of chimneys and things, I have a drawer full.

These are the longer joints such as tanksides to tanktops, or cab-sides to running plates. Alignment is the nasty part here. This is where a fast adhesive such as the Loctite IS 06 helps as one may tack two pieces together dead true in a second and then fill in with solder. But other means are necessary so lay the larger part flat as is possible and present the smaller to it, you may use a square or squared block to help keep the angle if you can, I depend on eye alone. Flux one end of the seam and quickly place a small spot of solder, allow it time to settle in. Now check the line, if it is wrong apply more flux and while it is boiling ease the parts true. This is an awkward job and I am glad that I can place parts together from the word go. Once you are satisfied, flood the whole seam with flux and beginning at the end away from the "anchor" work slowly along until you reach the anchor and merge it in. Remember that in so doing you must ensure that the seam is always held by cool solder so that alignment is kept. On long jobs this is easy and you can attend to the filling as well, but on short bits you may have to lift the iron away once or twice.

These are the smaller or more massive holds such as sandboxes, steps etc. Have the base or parent mass settled nicely and place the part exactly, use gravity if you can possible do so. Flood the joint with flux and apply solder at one edge or side, work it quickly round the rim of the joint but leave the last side open and dwell briefly until boiling ceases. Thus all flux has gone out and is not trapped.

The Wills cast kit of LBSCR class D1 as rebuilt. The kit can also be made as an E1 class 0-6-0T.

Boiler mountings
Fit them late on and always, but always, fit them to a hole. If there is no hole, as on many GEM kits, drill one, a good size at that. Place the model on a fiat, level surface so that you can look at it end on from the boiler front end, your eyes being at smokebox top level. Place the safety valve or other rearmost item and carefully set it upright and central, it may have to be filed slightly. Gently stick down the fore end with a lump of Plasticine without moving the part, and flux the back end or other convenient place of the skirt; aim for convenience and accessibility. Drop on a small blob of solder to the flux, again do nothing to move the part. You can now remove the Plasticine and flux all round the skirt. With a quite tiny bit of solder, about a panel pinhead size, set about the edge of the skirt well away from your first anchor, and ease the solder into the skirt so that none shows, moving gently round the skirt all the time. Once it is fairly secure you can shift the whole model to a more comfortable stance and merely hold the part in place by forefinger while you work round the whole skirt finishing off with the anchor. Any excess solder can be removed with that type of Needle File called a Pippin, see "Tools" about this, it is ideal for the purpose. Then the next mounting forwards may be tackled and so on to the chimney, lining each one by its precedent.

The reason for the hole is that you are in fact only soldering the rim of the skirt, and if there was no hole to the interior of the boiler unused flux would be trapped in there under the mounting. Hence either there would be a tiny explosion as you finished the run round, it could blow off the whole mounting or, worse still, the flux would slowly work through a weak spot in the soldering and emerge in a nasty blister just after you had finished the livery. The hole allows the unused flux to escape and also lets in cleaner later to shift any left.

If you want to drill out "solid" chimneys, start small and work upwards in size by easy steps and go very gently; I always finish off by handscraper, using the Skewdge referred to later. Don't try and hollow out domes, you need the weight which is one of the great virtues of cast kits.

Fixtures. Handrail pillars and such like.
Look at these well in advance, some boilers are entire and tenders often box up so that fitting must be done early; the trouble is that I find that makers do three things. They core small holes, these are often oversize which is a real pest, so I plug them with solder and re-drill. They cast in dimples. This is better so long as the dimples are there. The holes or dimples are not in line. With the crude things that happen to boilers, especially in the dies, this comes very often. I myself prefer to fill up the lot and re-drill after marking them out on the completed locomotive, but if the boiler is entire you can't then fit the pillars.... So I do my best to tape the boiler up as it should be and when the lower part of the model is ready for it I Plasticine it in place correctly set, and scribe the new line for the pillars, then I take the boiler apart and drill the holes, fit the pillars and finally assemble the boiler (and pray!).

Tenders and such merely need advance planning to ensure that all pillars are in place while accessible, this might be done at any stage up to the fitting of the coal plating or tank top.

When inserting the pillars, put through a short length of wire and insert the "Grudger" as per sketch, this holds the pillar and wire off the face by the right amount, spread the pin tails and bridge with solder. If you must use machined brass pillars then you must very finely tin them and fix them as per whistles etc. and again pray. Some locos such as GWR have one or more pillars on the smokebox door-ring and these must be threaded on to the complete handrail wire before it is fitted to the side pillars. Thus these end ones cannot usually be soldered in but the wire if bent neatly should hold them in place. LMSR ones can be fitted into the smokebox door well beforehand, but in that respect the LMSR or rather the MR before it was very sensible, alone among British railways. (All the others had the handrails far too high up at the front, you could not use the things!)

Cab pillars are those long handrails from cab floor to roof on some modern locos, and some old ones too. such as LNWR. To fit these, pop mark the positions on the cab step top and cab roof when the last has been fitted. Drill the lower hole at an angle inwards, about 10 degrees or so, you will not then emerge below in front of the step Drill the roof one dead vertical. Bend the wire at the bottom for the angled hole and drop it from the top downwards. Cut it neatly off, flush with the roof and spot with a pinhead of solder underneath, this holds it and looks like the little bush or palm used in full size. You may wish to put a spot of solder at the bottom as well, and possibly where the wire passes a beading of the cab look out; do this last one most gently to avoid melting the tiny lip.

Grab irons are fitted much as the handrail pillars,, in that a small bridge shape like a paper staple is bent up of wire to the necessary length and spacing of legs, allowing 3/16in over on the legs. These are put in the holes, the iron held out by the "Grudger" and the legs underneath or inside bent over like a paper staple. Then they are bridged with solder. In some tenders this will show at the front edge of the sides, eg LNWR ones, but here one must sacrifice a little neatness for security, as one cannot just sweat the legs in and cut off flush as with hard metal sides. Lean a shovel against the side to hide the mess if you like. Lampirons and the collection of hooks etc on the back of certain GWR tank loco bunkers are fitted much the same way, being formed of flattened wire and secured inside the model by bridging bent over tails. If on a GWR Pannier Tank do not forget the bucket. From this modellers may deduce how to fix other details of their choosing. Things like opening smokebox doors and what not always annoy me, fit them if you must, but as there are no tubes inside a model boiler, which is not a boiler anyway but the casing of one, there seems little point in having access to them. Unless it is to permit the escape of fumes from an outraged electric motor, the actual occupant of the "boiler"! Old hands will recall the ever adorable Bond's Peckett Tank in Gauge 0, the "Bonzone", and a fine model it was. I incurred parental hatred by opening the working sandbox lids and inserting sand therein. This is unlikely on a cast kit anyway. (Well, dammit, I dried the sand first, a driver at Manchester Central told me to always dry the sand!)

I am not going to say anything about the fitting of toy mechanisms in kit models, if possible always use a Tri-ang mech. because it is 100 per cent on the ball and easily converts to scale wheels, the wheelbase may be a bit off at times but when you are old and wise you will know how to make your own mech. Until then be sensible, However, GEM has issued some kits having mechs. in bits and these are emphatically best assembled by low melt solder. The only sure way is to afford a pair of ground parallels from a tool dealer, get ones about 5in long, and invest in a good quality plate glass mirror and length of 0.125in silver steel. Cut the last into three equal parts, filing a neat lead on each cut end. Solder the spacers to ONE frame only, usual techniques apply. Assemble the lot up with rubber bands, not too tight but nice and firm, and slip in the bars through each pair of axleways. Lay the lot on the parallels with those clear of the frames, and adjust the latter until all bars are sweet in the holes, then flux the unsoldered side and spot it, check again, and finish off. This is rather over-simplifying the job, but I cannot really offer better help even in a dozen pages. Do the loco body first, or rather do the tender first then the loco body, and you will have gained the "feel" to get the frames right. You may be able to dispense with the parallels etc by putting good flat track on the mirror and wheeling the loco with the frames banded together as before. Then you can pop her on the track and adjust the wheels until they are sweet, but it is a most tricky way to my feeling; I have not tried it. The main fault with the GEM frames is in the axle ways being in soft metal and not bushed like Wills. I have in fact bushed GEM frames but am not keen to encourage others to do it unless they know how to, in which case they would not ask. IF you buy a No 27 drill of top make, in high-speed steel only and IF your large drill brace is really good, eg Stanley double pinion, and IF you have a dead-on eye for level and squareness, then you can clamp the frameplate firmly in the vice and carefully open the holes to take Jenning's Bushes ("Tri-ang Conversion bushes"), afterwards pressing these gently in with the vice jaws. I wish George would do it himself! Wills frames are cast as boxes and need no comment other than that you make sure that they fit tinder the body without that twisting them.

So I will conclude the actual assembly matters by looking at this one. As you put up the running plate to buffer and drag beams check the alignment, but even so as the boiler goes on twisting can occur, the cast parts are full of little stresses which emerge at odd moments when least expected. My method petrifies my friends in that I clamp the one end of the body firmly in the vice and put a special hand vice I possess over the other end and heave the lot square. DON'T do this! Secure the model in the vice by the front buffer beam before any brake hoses etc are fitted. Grasp the cab evenly all round within the U-shaped hand, making sure you bear evenly on all parts, and with your body, not your arms, twist the model slightly overtrue. Let go and look. The resilience of this "soft" metal is surprising and two or three attempts may be needed. When she is happy you may have strained an odd joint or two and can remake as needed. I always do for several but that is how I find out the weak spots for my customers. I might say that one gentleman, in offering a kit for painting, assured me it had been assembled on a plate glass. Oh, dear! Take my advice and do it by eye and sort out the crinkles later. I had to take his apart in places to get it true. Remember that the best of them cannot always guarantee that these soft metal parts will stay dead true after packing and you must sort out some bugs yourself.

The toolroom
While modelling tools are a subject in themselves really for a separate attack over a number of essays, those for cast kits are pretty concise and lead naturally to a fuller workshop. So I will deal with them, and also introduce my own breed.

A good vice is of value. An exalted modeller wanted to know what a vice was for, he never used one. Mine is used as a hydraulic press, scrap reclaimer, anvil, match striker, and general holdall, it holds tools as well as models. It happens to be an ordinary mechanics' vice of 3in jaw width, the jaws being blind, that is ground smooth. These jaws may be ordered specially through tool dealers and are normal in toolrooms. They offer more friction area per given grip so are the best for delicate models. But I have tried on exhibition, with prior experience too, a new vice of foreign import and can recommend this Angula vice to all modellers in smaller scales. It has swing jaws through a full circle both vertically and horizontally and one set holds bar stock etc, whilst the other holds normally by smooth jaws. It may be got from Paddon Machine Tools Ltd. of 44 MaIden Road, New Malden, Surrey, price 53s 6d post paid, mail only. It can be screwed or clamped to the bench. It is not staunch enough for the Hamblings Wheel Press though.

One hand file, 4in bastard cut, is desirable for roughing off large lumps of flash etc. Otherwise a full set of needle files, Bedford No 0 cut, should be got. This is a set if 12 in a wallet from (if necessary) John Hall (Tools) Limited, Bull Ring Centre, Birmingham, price 38s 0d post paid. Specify No 0 cut, this is coarse like the bastard cut, and is essential for the soft kit metal, ordinary No 2 cut files will clog in seconds. No 0 is scarce but the above firm always seems to carry stocks and will gladly mail them.

Twist Drills
Nos 68 and 74 are needed for the handrail pillars and grabiron holes. Others could be got perhaps and I suggest that the Dormer Set No 5 is a good buy. It covers all BA screws in tapping and clearing and you would be surprised how this suits most modelling needs, apart from the screw sizes. Current price not known, mine are ancient.

Pliers and Sidecutters
Small ones about 4 in long are best and here pay as much as you can possibly manage, they will stand by you. The best cost all of 40s 0d a pair yet these will not let you down; I have had cheaper cutters break on ordinary small brass gimp pins. Anyway, your grandchildren would have to pay £6 for the best so you might as well buy ones you can hand down, along with some good models made with them!

These can be a help and yet again money buys the goods, from watchmakers dealers. S. Lanzetter, of 15 Shudehill, Manchester 4, will supply a good Swiss pair for 18s 0d post paid. These will hold tiny things secure and not "ping" them across the room just when you are ready to place them!

A small rule divided in millimetres only is of use, if it is a good one it forms a straightedge as well and the new NPL design of 5in rule is good, it will help you to equate inches with metric, as if we modellers needed helping! If you are stuck, John Hall above will supply it at 10s 0d post paid.

Hamblings alone seem to sell a set by Moore & Wright which give two—a flat and a three-corner one, the other is for scraping bores and not of much help to us, but the set is worth the total cost for all that. The scrapers must be sharpened on a fine oilstone, a coarse one or a grinding wheel will cause the edge to make deep scratches on the kit metal.

The most useful scraper of all you must make yourself, by killing one of the new needle files, the one called Barrette, having three faces, only one of them armed. (Hence this file tends to wear out quickly anyway.) When this one armed face is ground smooth and all faces stoned up you end with a most excellent tool which I call the "Skewdge", a cross between skewer and gouge, it does a host of odd jobs about any metal or plastic model from getting flash out of window openings to clearing internal corners of excess solder, it is at its best on female curves such as cab lookouts, the frame openings of many tenders and so on. 

The Vanishing One is drawn here, along with the 'Grudger", both being easily made from oddments; the "Grudger" may be of wood but the VO must be solid stuff. I call it thus because it looks like a bit of frame brass and tends to get lost among model parts. No prizes for a better and briefer name, but suggest one if you can. I do not think Mr Sid Stubbs calls his anything in particular. The "Grudger" just grew to be called so.

Lastly a wood chisel, and here money buys safety as well as quality. You need a top grade bevel chisel of 3/16in or 1/4in width, pay at least 15s 0d for one, and it must be kept razor sharp at all times, and you must strictly observe the rules of safety. Take note of that, if this chisel hits you it will go deep and take some kit metal or solder down there, which means hospital treatment and a lot of pain and festering. Therefore, you either keep both hands on it. or if you must hold the model in one hand (as it happens often safer that way) then make quite sure that no part of your body is in the path of the chisel whichever way it might slip.

Given these strictures of safety and sharpness you will have a very valuable tool to supplement the scrapers, these types of tool do most of the work on a kit model. Used upside down the chisel will pare out the inside of a splasher to give wheel room, a common task this, used with firm, rigid paring strokes it will remove the harder and bigger casting blemishes, especially where no file will reach, used with short, jabbing levering strokes it will get right into an enclosed corner such as no other tool will, used like a plane it will pare away an edge even of brass with great efficiency and accuracy, the novice may do far better with it here than with a small file, at least for the final touching up. Since I decided to try a chisel on my kits I have not looked back and offer the tool to everyone concerned with small models. But in working on metal you use much more local force than with wood and the risk of injury is thus greater if you ignore the golden rules above.

Of other equipment little is required. A junior hacksaw, not a piercing saw, may be useful especially in adapting kits. A pair of household size pliers is advisable for closing split pins in the vanishing one, small pliers may let go with a rush.

Soldering iron
The soldering tool should be a mains electric iron of about 15watt capacity, 25watt is rather high, low volt irons lack the heat storage needed for long seams. I find the Henley Solon 15watt just right, and similar tools such as by Antex or Adcola will serve. There are special irons that switch off at preset heats to be had, but these are costly and I feel that they lack the storage, my Solon is hard pushed at times. The iron must be stowed on a good block of metal when idle or else the low melt solder will burn away on the tip. As this happens anyway about once an hour, you do not want to encourage it. To prepare the iron when so burnt file the tip clean (while hot) quickly and cleanly tin with normal solder, and then tin with low melt solder. My metal block is a 12lb lump of cast iron having a hole drilled to take the iron tip, but an old flat iron or similar will serve. Radiant stands are no use~ I find, the tip still gets up to melting point of normal solder, so burning the lower melting point solder.

You need a "Bosh", that is a tank of water for plunging things. I use a polythene lunch box minus lid, it holds about 1 pint of cold water in which I put about 10mI of ammonia (2 small teaspoonsful). Along with this "bosh" have a small stiff brush, mine is an artist's hogshair round one and has lasted 10 years for its moderate cost, yours should last a lifetime. Use the bosh and its contents all the time. Always dip a file or drill in it to delay clogging with the soft metal. Always brush off a joint after soldering to remove excess flux thus avoiding deposits that hinder paint drying. Dump the whole model in at times and give it a wash round. The ammonia helps the water to "wet" the tools or job and neutralises the flux. The tools will not go rusty, mine never have done yet. After a few days the bosh will smell somewhat fruity, especially with kit metal waste in there, and a routine of washing and refilling is desirable.

Keeping tools clean
Using very soft metal causes tools to get rather hammered, files especially, but the ammonia water helps a lot. Still, you should repeatedly relieve drills, the small ones in particular, and you should card off the files each time you use them. When they do in fact pin up, pick out the teeth with a darning needle, Oddly enough new files are rapid victims and I find that a short time of work on brass or steel improves them, probably by removing burrs from the teeth. If drills are allowed to bind when dry they will break like lightning and the remains will fight attempts to remove them. So keep them wet. With all tools work rather slowly, fast cutting raises the cutting edge temperature and melts the kit metal on to it.

Last rites
You have built your model locomotive, you have cleaned all tools and put them away tidily, made a note to renew the broken drills, visited the hospital Out Patients Department and had a festering hand cleaned up! You haven't yet been scalded by boiling flux— there is time (!), and you have not melted the smallest whistle or holed the thinnest tankside. What now? Simply a jolly good bath for the model. The "bosh" should be drained and washed out, or if the model is too big to fit in, select a polythene basin, always handy around the workshop. Also obtain some "foaming" type scouring powder, or at least a good strong liquid detergent. The powder is best. Put about 1 inch of hand hot water in the "bosh" or basin and drop in the model. Do not worry about tender or bogie wheels, they will do no harm, but of course the mechanism is put aside somewhere. (It may have kit assemblies on it that need washing off, or you may have to strip it of motor and gears and wheels if it is a kit metal one.)

Have some scouring powder in an old tobacco tin or similar, wet the stiff brush (used with the "bosh") and set about the model with vigour. Keep lots of powder going in and let it foam away especially right inside where the brush will not go. Give the whole model a thorough and systematic scrub and swill it off in the water. Change this to a clean water and repeat the scrub-up, making sure plenty of water swills around internal parts. Again rinse off and examine carefully to see that all powder has gone. Finally, if you have mixer taps set them to hand heat and run the whole model around under them to get it nice and warm, If your taps are not mixers, fill the basin with hand hot water and let the model lie in there for a couple of minutes. When it is nice and cosy take it firmly and shake it vigorously to throw off most of the water. Choose a wide space for this and keep hold of it! The residual heat will start the model drying out, a warm place for a day will do the rest. After which you may lightly degrease, and apply the sealing paint. Then you will discover that you have left off a footstep somewhere!

This concludes this series which has appeared each month from the February issue.

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