Nick Lawson

@MarkC Thanks Mark. "Rescue" sounds ominous. How badly has the poor little thing been mistreated?

A digression away from smokeboxes: The loco's sandbox feed was controlled from the cab by a visible rod along the side of the boiler. The kit instructions tell you to run a piece of wire from the nearside sandbox back to the slot in the cabfront. However - something I happened to notice while looking at the Isinglass diagrams and confirmed by the photos in Yeadon - the J21 arrangement is different: the rear end of this rod is run inside the firebox cladding. Therefore, when preparing the J21 cabfront, one can fill the slot in the cab front. I was going to repeat what I did for the first boiler and construct a firebox front from scrap etch. As I detected the difference above in time, I was able to drill a hole in this firebox front to take the sander rod before soldering the front in place. Secondly, photos show that the sanding control rods were flat bar, so round wire isn't quite the thing. Luckily, the J21 etch includes a nice long, straight scrap edge about 0.8mm wide. This should be fettlable into a suitable rod, although I'm not sure that the rod will fit in a nice horizontal line from the top of the sandbox to the underside of the boiler. Even better from my point of view, there should be enough scrap to export some across to the J25.

Second boiler I took the second, unstarted boiler barrel and tried to make it a smaller diameter. Firstly I rummaged in the garage for scrap timber and constructed a toilet-roll barrel holder with a “dowel” of about 16mm. (Actually a bit of a dead box bush from the garden, that I had turned down). To make the boiler smaller I had to push the join beyond the designed half-etch. I scored a guideline 1mm beyond the half-etch overlap and hot-taped the barrel to that line. I then worked over the join to press the edge down and soldered it closed. Because the join is not on the inside half-etch it creates a bit of a ridge which works against the reduction in diameter. Also of course there was some ovalling, which I evened out as best I could by finger pressure. This second boiler barrel is about 18.4mm diameter at the front, so still too big, but about 0.5mm smaller than the first one. At least, when fully wrapped the smokebox won't exceed the 20mm it ought to be. Here are the two together, both with their inner wrappers. The inner wrapper as supplied is too wide, so for the second one I reduced it by filing, but over enthusiastically removed too much, which is why the wrapper is set back from the front end. This mistake will be covered by the outer wrapper in due course.

Boiler assembly – take 2. Ok, rewind. All measurements in the following are approximate, even if to 2 decimal places. They are for illustration only, as they depend on the accuracy of my inexpensive vernier; my own inaccuracy using it and, sometimes, thick lines on a diagram. “Isinglass” here means the Isinglass J21 diagram, or really those parts that relate to the earlier saturated boiler later known as diagram 67. All measurements taken from these 7mm scale diagrams have then been altered to 4mm scale multiplying by 4/7 by calculator. Boiler barrel diameter 1. The prototype boiler diameter is 4'3” = 17mm, to which cladding has to be added. 2. Isinglass gives a boiler diameter of 18.28mm, suggesting cladding slightly under 2” per side. 3. The aperture in the LRM cab front for the boiler has a maximum width of 18.2mm which seems about right. 4. The pre-rolled (but not fixed) LRM boiler barrel when squeezed together such that the overlap is completely closed gives an outside diameter of about 18.9mm, so it is too big. At the firebox end it can be squeezed into the cab front though. 5. The Isinglass smokebox diameter is 20m. A kit boiler with almost 19mm diameter with two layers of smokebox wrapper applied will be more than 20mm. 6. At the smokebox end the 18.9mm boiler is larger than the fold-up smokebox front, which has a diameter of 18.6mm – i.e. even before applying the smokebox wrappers the front is smaller than the boiler diameter. 7. The boiler diameter appears to be slightly bigger at the front than the back, which may explain why earlier I had an apparent upward slope to the front – i.e. I had a tapered boiler, but heading in the wrong direction! I have no idea how this can be - the seam along the bottom of the boiler looks right. 8. The smokebox wrappers are too wide but can be filed down. More on this another day. I ummed and ahhd what to do. In the end I have taken two different approaches. Firstly, I have resisted the temptation to dismantle the boiler already assembled. Its just going to have to be too big. However, I have improved the look at the front end by sawing the too-small smokebox front off the fold-up etch and replacing it with the discarded, larger front which has the correct 20mm diameter for the smokebox and matches the diameter of this boiler with the inner wrapper applied. I have yet to apply the outer wrapper to this assembly, but when slid over the wider front it will fit neatly, but make the smokebox diameter oversized by about half a mm. Although the round part of the smokebox front is the correct diameter, I did have to file the bottom of the sides which otherwise would obstruct the front splashers and sandboxes.

Some further light having dawned, I will spend some time taking some more measurements off the Isinglass diagrams before proceeding. There will now be a short interlude. Unless anyone knows of any inaccuracies in the Isinglass J21 diagrams?

smokebox (2) Some light having dawned - the stated intention of the kit designer is that the inner wrapper be flush with the end of the barrel; the front butt against these two; and (less obviously) the outer wrapper cover the front and be flush with its leading edge. As the inner and outer wrappers have pretty much the same width, this means that the trailing edge of the outer wrapper is further forward than that of the inner wrapper by the thickness of the front, resulting in a double step down from smokebox to boiler barrel, of a sort that I previously wrongly claimed was missing. This is what the instructions meant when they talked about the larger and smaller wrappers - the finished result, not what comes off the etch. The fold-up front appears to be too small in diameter so I wondered about making use of the old, discarded-but-still-present smokebox front. I haven't mentioned this so far, but I have the Isinglass drawing for the J21, so I tried to scale the smokebox dimensions from these 7mm drawings. Regrettably the front elevation lines of the smokebox are quite thick so hard to get an accurate measurement, but as far as I can see, the old smokebox front provides pretty much the right look of the loco as seen from the front, i.e. including the thickness of the wrapper. It is thus too wide for the outer wrapper to slide over as intended in the kit but could butt against it giving a good effect at the front, consequently removing the step down at the rear of the smokebox mentioned above. I need to look more closely at the width of the smokebox and shape of the step down on the prototype and see whether I care about losing this or whether I'd rather fabricate my own anyway. It ought to have a rounded section. Alternatively, the newer fold up front is too small I can see that using it would involve filler somewhere. I am still thinking about this!

I like this! Thanks, I'll get back to you.

Smokebox (pt1) There are two smokebox wrappers, inner and outer, and a fold-up saddle and front. The instructions confusingly claim the inner wrapper is a. supplied ready-rolled and b. is wider than the outer; neither of which is true. All these components are flat-packed on a separate etch "E". The inner wrapper has "inner wrapper" etched into it, so there is no mistake. If anything, the outer wrapper is 0.1mm wider than the inner. Also, NER boilers had a distinctive step down from the diameter of the smokebox to the boiler barrel which the kit doesn't cater for, so a bit of fettling will be required to add that afterwards. Having got over the above, I folded up the smokebox saddle and plonked the boiler into it. On a flat surface it was clear that the boiler wasn't level, sloping up to the smokebox end. As sometimes there is some leeway in folding up an etch, it might have been that I had folded it in such a way that the rear of the saddle was higher than required. To check, I very carefully folded up the second saddle such that the rear had the minimum height. Boiler still sloping; and this was without the inner wrapper in place, which would have raised the front even more. I needed this wrapper in place before making the final fit of the saddle, so diverted to rolling the wrapper. I'd never done this before and the result wouldn't win any prizes; but wasn't too bad. Mostly. Then there is the matter of how to solder it in place. The instructions advocate a gas torch and solder paint; neither of which I have, or have ever used. Instead, I tinned the inside of the wrapper, positioned it and rested the inside of the barrel end on a piece of dowel in a vice. I started on the top and worked down each side with iron and a wooden prodder to keep the molten bits in place. I ended up with quite a nice fit on the rear edge, but not so much on the front. I think I need a longer bit of dowel to push all the way through from the firebox end which would allow me to get iron and prodder onto the front part of the wrapper. I may have another go. (I found myself thinking of the lovely picture of a real atlantic boiler hanging nose down while a riveting machine fastened its smokebox. ) Anyway with the wrapper in place, I then filed down the rear of the saddle about 1 mm and tidied up with emery wrapped round the barrel. The level from the side is now about right. In passing, you can see the fold-up smokebox rear doesn't align with the rear of the wrapper, but this will be hidden by the outer wrapper and front wheel arch. Of course the altered level now means that the barrel is lower than expected compared with the front end. Also, the front appears to be a smaller diameter than the barrel, even before the addition of the outer wrapper. As far as I can see, the prototype's later superheated boilers did have a rounded end to the smokebox that this could simulate, but this kit is for the saturated boiler with smaller smokebox, which appears to have a squarer end. This kit includes some items that are to be discarded, including an old smokebox front. Interestingly, this has a larger diameter than the fold-up version, which would give the kind of nice square angle to the front which I'm looking for. I feel a Cunning Plan coming on....but first back to the inner wrapper.

Well you could perhaps decide that it has inside valve gear with a transverse lever mechanism out to the outside piston valves. Or is that too GWR for you? https://modelengineeringwebsite.com/6000_King_George_V.html 😀

Ah yes, duh! Sorry.

Do you have a part number or something?

@Chas Levin Thanks Chas! Today I set off in one direction and ended somewhere else entirely. I had been a bit dubious about the rolled boiler which didn't have a neat join along the bottom. The instructions don't actually tell you to solder the join, so I wondered if I was missing something. Today I compared it with the second boiler, as yet untouched, and I realised that simply the first one had the inside end of the roll on the outside. I've lost track of which is which, but I'll assume that this wrong 'un was the secondhand kit and had been fiddled with by a previous contestant. It only took a minute to put it the right way out, after which it closed up nicely; so I whipped out the iron and sealed the bottom edge before it changed its mind. The kit provides a couple of small pieces to hint at the existence of a firebox front under the boiler; but really the firebox front is largely open. Presumably this is because of the style of drive mechanism current when these kits were designed. Or just that digital cameras that pick up every slightest thing didn't exist back then. As I won't be powering the centre drivers I don't need this opening. A quick rummage in the scrap brass box produced a piece almost exactly right to fill the gap down to footplate level. I sawed and filed the inside to shape so that I will still be able to stuff the boiler barrel with ballast in due course. If nothing else this manoeuvre was probably easier than trying to solder the pair of supplied pieces in the correct position. Looking at the picture above, I can't get over how enormous those handrail knobs look - particularly compare to how tiny they were when Mr Sausage Fingers was trying to fit them.

Sliding windows Slightly out of sequence: The rearmost windows on the prototypes slid open. The kit thus provides a pair of window frames and four strips to represent the top and bottom boxing. The instructions tell you to solder the strips to the inside of the cab sides, warning you to avoid dislodging the handrail knobs you have previously soldered through from the outside. While I was thinking how/where to position the strips on the cabside I noticed that the instructions actually don't mention fitting the windows between them at all! I decided to create sub-assemblies by soldering the strips to the top and bottom of each window frame. These can then be positioned on the cabside in one go. I was going to use 188 degree solder for the knobs and 145 for the strips as a way of improving my chances of avoiding the warned meltdown; but then it occurred to me that it would be much easier to glaze all the cab windows if I don't solder these windows in now at all. Instead I will glue them in after glazing. Having soldered each set together,I looked again and thought the strips looked a bit undernourished. (Sorry this is not really apparent in the blurry pic, but they are no thicker than the window frame they are supposed to be enclosing). I tinned some strips of scrap etch and plonked them on the top.Then I looked at again at the prototype: and decided I'd gone from undernourished to "fat boy", ...so I had the whole lot apart again. Take three: I replaced the original thin strips altogether with some 0.7mm square rod (point rodding from Wizard). I think this looks about right, especially as nobody will ever see it after the cab roof goes on!

Loco body 1 The kit was made originally for the J25, so if building the J21 one starts by filing out the footplate for the larger wheels. As you need to take out 2mm in various places I did try assembling a piercing saw through the middle, but it is in fact easier and less faff just to file. This requires care at the rear end where there are very fine webs (is that the term?) in the middle which need to remain. The firebox sides will sit on them. Pic 1: J21 (left) J25 (right). Construction of the loco body then starts by assembling the 2-part dragbeam, 4-part bufferbeam and fastening these and the two valances underneath the footplate. The instructions suggest aligning the parts for the bufferbeam using a pencil. I tried this but had mislaid my extra hands so didn't have enough for this. Instead I resorted to knocking up a little jig from scrap ply and barbecue skewers. ("Here comes the sun di-da di-da...") 3 I still didn't manage to get the bolt heads on the buffer flanges looking perfectly vertical and horizontal at the same time but this may be down to the etch. Yes, that must be it! The jig is now well carbonised, but it held together to do loco and tender bufferbeams for both locos, so that is all eight of those pesky little flanges attached. The assembly of the above ingredients on the footplate is fun as there are no locating guides for anything. Very satisfying afterwards though! It starts with the drag beam, which fits flush under the footplate end. However the beam is slightly narrower than the footplate, so it thus needs to be centered by eye. The instructions then say to add the valances, set in from the edge by 0.25mm before adding the bufferbeam which goes the full width of the footplate, but set back a smidge to butt against the valances and leave a slight overhang at the front. I decided I'd rather get the bufferbeam right first and fit the valances afterwards. I taped the valances flat against the footplate to provide a guide for the position of the bufferbeam. Also, last year I noticed other modellers referring to blutack. Having only just removed the last vestiges of this substance applied to our house by the now-flown children, I have acquired a pack of my own for the first time since the 1970s. It came in useful supporting the bufferbeam (at the angle determined by my square). I then untaped the valances and set one up between the two ends. Blutack again. The inset from the side edge may or may not be 0.25mm; it was just determined by the inset of the end of the drag beam. I tried to maintain this along the length while tacking it on, but as they are quite flimsy it was very easy to push out too far with the iron at the wrong moment, so there were a number of adjustments. Ditto for the other side. This kit has a number of flimsy parts which need care while filing off the etch tabs. I've found I now just file off those tabs that prevent me fastening a part in place. Afterwards it is easier to file off any remaining tabs. The valances were in this category and I still need to finish the lower edge properly.

Tender body Having put the tender frames to one side pending a decision on springing as described above, I started on the tender body. The first stage is easy enough to fit the tender back to the footplate. The instructions then blithely tell you to solder the sides to the rear and to the footplate, getting the sides parallel to, but set in from the edge of the footplate. Having done this, then insert an intermediate vertical support between the sides. This seemed ****-about-face to me. The more obvious approach was to solder the intermediate vertical to the footplate (pic1); and then tack solder each side to this and to the rear, before using a straight edge to keep the side straight along its length while soldering it to the footplate. I think the reason why this is not suggested is down to the slop in the provided tab-and-slot on the intermediate support. However, it is not that difficult to align that piece centrally across the footplate and solder it in. My alternative approach above then becomes feasible and, I would argue, preferable. Some care is needed as the intermediate support is quite fragile, but with the side soldered to it and to the back one has got the side vertical; and it is then easy to do the rest. I admit I did make things "exciting" on the first side as I had underestimated how the solder would flow and temporarily soldered my steel ruler to the workpiece. Memo: oil it next time! Anyway this approach worked for me, so I did the second tender the same way. I have not proceeded any further with these tenders for now as: Although I have soldered retaining nuts to the footplate, this was a mistake as I may need to adjust them slightly when I have assembled the frames and see how these align. Mostly though this tender body will assemble pretty much into a closed box, Before I take it further forward I need to know how the wheels will align and pickups be fixed; and where some lead weight can be added.