Scrap Tank Test Build – Part 6; Boiler and Running Plate
Now that the much of the bulk of the above running plate work has been completed, the running plate valences can be fitted. As these are nearly always long and thin, they are prone to distortion in the kits I have built – so it is time for another jig!! This one holds the valences at numerous places to stop it flexing and to hold it straight.
With this, it is a doddle to fit the valences in their correct place and solder them without distortion. I did find that the running plate flexed significantly at the end of the tanks; so the final version is going to include a pair of temporary stiffeners that fold down and stop this. This would be the moment when they are removed to allow the valancing to take their place.
And onto the boiler. In a departure from normal practise, I am not including a flat etch to be rolled into a boiler – it is relatively difficult to get even a pre-rolled boiler into a neat tube without a visible seam and if you do not have a rolling machine it is effectively impossible to do so. In addition, where boilers have been half etched to create boiler bands I find that the half etched elements that remain are overly delicate. This was something that caught me out a while back when I drilled such and area to take handrail knobs and badly distorted the metal – this kit is still sitting in its box now and I am probably going to have to replace the boiler.
With these problems in mind, I simply used a piece of brass tube from Eileens; easier and much more durable and if I were sratch-building I would not even think of taking a different route. This did still leave the need for some rolled parts, to make the smokebox and I have sought to use another little trick here to make these easier to fit – some tags and eyes. The tags are strips of half etching that pass through the eyes and then tugged back. This can’t impart a curve into the metal but does allow the parts to be pulled tight and makes it easier to solder into place without much of lip. Mind you, they were a tad short and will be lengthened slightly in the production run.
A second additional laminate is then needed to form the outside of the smokebox and down onto the saddle.
I did find another little error when it came to the front of the smokebox. Whilst the diameter for the front that I had drawn had allowed for the thickness of the two laminates, when you fit these there is also a layer of solder between them and whilst this ought not be that thick, it was just enough to make the fronts too small. In the production run, I will deliberately make this a tad too big as it is easy enough to file it back but much more difficult to add the missing metal (I didn’t, I just made a fresh one from sheet metal). The smokebox door is not mine, the door from the Lochgorm Models Loch is the right size judging by the photographs (note the drawing in the old man’s book has it being smaller but this does not match the photos, so I ignored it in this respect – sorry Dad!).
The downside of using tube as a boiler is that boiler bands need to be considered. I have provided these in the kit (again using the strap and eye technique). I chose to fit them on this kit although in practise I think any metal boiler band is too thick and would probably have done it with a transfer sheet if this was not a test build (done prior to painting, the thickness of the transfer is enough to show through the paint on what will be a single colour to the boiler).
Only the top of the boiler is visible after the first ring and a bit, so can be cut away to leave lots of room for the motor, weighting and DCC chip. I may try and fit this with sound, so who can give a view on what it might have sounded like – a jinty is my favoured guess?
Posted on April 15, 2015, in Miscellany Models, Workbench (stock) and tagged EM, etching, highland, Highland Railway, Lochgorm Models, Miscellany Models, Model Railway, Peter Drummond, Scrap Tank. Bookmark the permalink. 4 Comments.
I am following the assembly of your kit with great interest as I have an ex GE/LNER F7 tank engine by Alan Gibson to build.Keep up the good work
Best regards, Peter
A GE F7, that will be very lost to appear in New South Wales! I suspect a friend has built one, I will make some enquiries as to whether there are issues.
Thank you it’s appreciated. I have a long term project called Capel St Edmund based on the Essex /Suffolk border in EM so the loco will be at home there.
It is alright son, not my drawing but Ken Leach’s, done from photographs probably during WW2. Dad