MOK 8F 8425 – Replacement Brake Clevis

In between times I have managed a little more on the 8F. The next job was reassembling the brakes. One thing that has bugged me for a few years is that one of the clevis castings hadn’t fully formed when casting.

Misformed Clevis casting

It would have been easy enough to just solder it on and have done with it but I remembered fellow modeller Tony Geary making some clevises to add detail to the brakes on one of his builds so I decided to have a go at one myself.

I started with some square bar and turned a round spigot on the end. Then I reduced the next few millimetres down to the size of the arms of the clevis using a small Dremel burr as a milling cutter

Dremel Type Burr

a bit of hand filing gave me the basic shape

Basic Replacements

Then I drilled a couple of holes in either end of a stub of brass bar and temporarily soldered the two parts into it.
This allowed me to cut the slots. I do have a full sized slitting saw for the mill but a couple of years ago while in one of the cheapo trading stores I bought a set of slitting saws for a Dremel type tool (notice a theme here?). I think they were a fiver for the full set.


I fitted it into the mill with a 0.8mm blade (the pack has several different thicknesses from 0.4 – 0.8mm) and I was really surprised at how little run out it had.


This is the end slit and then finally the finished clevis


MOK 8F 8425 – Solving The Enigma Was The Easy Bit!

Having worked out how it all fit turned out to be the easy bit!
Assembling all the elements together with the balance weights was like trying to plait fog. You have to slip the cross pin through eight separate holes in the subassemblies. Much muttering ensued before I got it all together.

MOK 8F 8425 Water Scoop Mechanism
MOK 8F 8425 Water Scoop Mechanism
MOK 8F 8425 Water Scoop Mechanism
MOK 8F 8425 Water Scoop Mechanism

Although they are shown on the isometric drawing there is no provision for or mention in the instructions of the support adjuster rods for the scoop. I made them from some lengths of rod and microbore tube.

MOK 8F 8425 Water Scoop Mechanism

I have made a few of these Stanier Tenders by now and this is certainly the most detailed that I have done to date.

MOK 8F 8425 – My personal Enigma Finally Solved

Today I finally cracked my enigma. One of the reasons that the build stalled back in 2018 was that I couldn’t for the life of me work out how the water scoop mechanism went together.

At this point I need to say a big thanks to fellow Guild member Ian Allen for pointing me in the right direction. As with all things when you know what to look for it is there in the instructions it’s just not that clear.

My problem was the arm that goes alongside the inner chassis.

MOK 8F 8425 Tender Water Scoop Mechanism

I initially had it located in between the clevises at the front. When it needs to fit behind. This meant that when trying to fit the wheels the rod fouled them

MOK 8F 8425 Tender Water Scoop Mechanism

Once I knew this it made things a bit clearer then I discovered that I had the linkage that the water scoop attaches to upside down.

MOK 8F 8425 Tender Water Scoop Mechanism

With that corrected I was able to get it to fit together. It still needs fixing permanently in place but I have the balance weights to fit yet so I will wait until I have done that before making anything else that I might have to undo!

MOK 8F 8425 Tender Water Scoop Mechanism

MOK 8F 8425


I managed to progress the tender for the 8F a little more over the weekend and now the outer frames sport axles boxes and springs.

MOK 8F 8425 Tender underframe – springs and hangers fitted

As can be seen from the inside, I soldered them on (with 100 degree solder). Before fitting them I added a small blob of 100 degree solder to the back of each spring damper. Once I had soldered the spigots from the inside I pressed on each damper with the none pointy end of a pencil and used the RSU again from the inside to quickly melt the solder, firmly attaching the dampers.

As an aside, as I got them out to the box I noted that one of the dampers had broken off and I spent sometime reattaching it using 70 degree solder. I was just about to fit it when I saw that I already had the six that I needed. Dave sharp must have noted the broken one when he packed the kit all those years ago and popped in an extra.

MOK 8F 8425 – Lamp Irons Fitted and Tender top complete

Over the weekend in between checking over the Princess Firebox drawings, I fitted all the new lamp irons and I am happy that the upper tender is now complete.

MOK 8F Replacement Lamp Irons fitted
MOK 8F Replacement Lamp Irons fitted

I also straightened the middle lamp lower iron after seeing the photos

I also replaced the etched Irons that are built into the MOK etches for the storage of spare lamps on the tender front.

MOK 8F Etched lamp irons
MOK 8F Replacement Lamp Irons fitted

I really should have done a better job of rinsing away the Flash liquid residue as it has left tide marks.

MOK 8F 8425 – Remaining Lamp Irons Milled

Today I have made the final set of lamp irons for the 8F and thought I would share the method because it occurred to me that while I have used the mill the same result and basic method could be followed by someone with a file.

I started with some flat nickel bar 

Nickel Strip

I cut off four 40mm lengths and soldered them together.

4 Strips soldered together and Cleaned up

Once soldered together I milled all the edges flat. I needn’t have done the ends but with the mill it was a simple task. Here I have milled out the front of the iron.

Milling four irons at a time

Then I turned the block over and milled out the rear

Four irons milled but still attached to each other

This is the finished job before cutting off with a piercing saw and separating them.

Lamp Irons ready for finishing with a file

The finished individual lamp irons ready for final clean up with a file.

From the 40mm strips, I got eight lamp irons and I have enough material left already soldered together for a further eight which I will cut and put in the spares box.

MOK 8F GWR Double lam Irons – Milled from Solid.

Sep 15, 2017

Needing a bit of a break from re-drawing the Firebox for the Princess my thoughts turned to front lamp irons. As I was working out what was needed I got side tracked by working out how I might machine some of the double lamp irons that the GWR fitted to the 8F’s that they built

Milled Lamp Irons

Not the best photo as it’s a snip from a much larger photo found on the net to illustrate what I am talking about. The MOK kit does provide etches to make up this version of the lamp irons but I am not keen on etched lamp irons. I also thought that I would like to do them from nickel as the rest of the kit is nickel but I didn’t have any nickel bar thick enough. I do have some 5mm rod so my first step was to machine the end square in the mill.

Then it was a case of working out how best to mill out the bits in between the lamp irons.

I milled a groove down one corner of the square section and then rotated the part to carefully mill from the opposite corner to leave the two upright irons

Milled Lamp Irons
Milled Lamp Irons

the tops were then rounded with a file before cutting off the main piece. I could have transferred the work piece to the lathe and part it off but I just cut it with a piercing saw them popped it in the vice jaws and milled the bottom flat.

MOK 8F 8425 – Tender Buffer Heads

Back when I got this kit 12 or more years ago there were no buffer heads in with it. Apparently they were supplied by Ron Chaplin and he had just retired.
I really should have pestered Dave Shap for some replacements but time went on and it’s too late now. To get around it I imported the drawing into Fusion 360 and scaled it I then drew up the head to get dimensions and from there a happy few hours were spent turning some from some mild steel bar.

I wasn’t thinking when I picked up a 6ba screw/nut thinking it was 8ba. I drilled out the buffer castings to take 6ba before realising my mistake so I made the buffer heads to take a 6ba nut. Fortunately I found some suitable springs.

MOK 8F Replacement Turned Buffer Heads

They just need blackening now.

MOK 8F 8425 – Cast Works plates

Recent talk of printing works plates by guys on another forum got me thinking about the fact that I had managed to find an auction house image of the actual plate fitted to my loco which I downloaded. I managed to find it again today and shared it for comparison purposes only. 

When scaled and enlarged the font doesn’t match anything that I could find so I ended up drawing each letter/numeral individually.


The images are much enlarged with the text and rim being only 0.2mm deep

MOK 8F – Replacment 3D Printed Tender Brake Blocks

Some time ago a fellow modeller who was building the same kit had some 3D printed brake shoes done. He very kindly sent me a set and they have been sat waiting patiently ever since.

While working on the other bits over Christmas I have been pondering the best way how to tackle fitting these. The brake hangers on Stanier tenders are curved so to replicate these my thoughts ranged from turning circular strips from sheet to bending strips from flat bar. In the end I gave my self a mental kick and thought why are you trying to ‘save’ the castings, you will never use them now that you have fitted 3D printed replacements.

So the next thought was right I need to remove the cast on, shoes from the hangers. Ian, the guy that had supplied the printed shoes also sent a note with some suggestions as to how to go about it. His first suggestion was to use the pips on the cast shoes as the location for drilling out the hole for the pin. I duly filed the pip down on one side of each casting until it was just a witness mark and then punched it. I used a pin vice to drill the first one and though sod this for a game. I drilled a hole in a lolly stick to take a 1mm drill bit (the same sized hole as the top of the hanger). I popped the leg of the hanger in the vice along with the bottom of the drill bit, which was inserted through the hanger and then the lolly stick. This held the casting firm enough to drill through it with my Proxxon mini pillar drill. The rest of the drilling was done in no time.

I tried the same set up to hold the casting to file off the bulk of the cast on shoe but using a file was hard work so my thoughts turned to milling them off. To use the mill I needed to hold them much more securely than a piece of lolly stick would allow. So I made a fixture from a piece of brass bar.

Fixture for holding brake castings while milling.

For the first side I just drilled a couple of holes at the appropriate spacing to hold the leg of the casting and the drill bit passed through the hole as before.

For the reverse side I didn’t have the leg to give me the secure holding so I milled a bit off cutting art way through the leg hole

Machining a Fixture for holding brake castings while milling.
Fixture for holding brake castings while milling.

Which gave me this.

Fixture for holding brake castings while milling.

Once both sides were milled I used a mini sanding drum in my Dremel to take off the last bit and restore the inner curve.

MOK 8F 3D Printed Brake shoes fitted

The last task was to insert some brass pins and superglue them in place while allowing the shoe to still pivot.

Next job is refitting them to the tender chassis as I had already fitted them some time ago.

MOK 8F – LMS 8425

Once I had sorted the errant part 146 and made the tender top fit I also fitted some rivets strips around the edge of the top plate that I had missed, moved on to adding the details to the tender front.

Brake and water scoop windlasses, water gauge and water scoop indicator rod. Plus another couple of levers whose role escapes me.

MOK 8F 8425 – Tender front details
MOK 8F 8425 – Tender front details
MOK 8F 8425 – Tender front details

The windlass handles were soldered to the cover castings using 295 degree solder and then the castings were soldered in place using 100 degree solder to make life easy.
The backs were tinned with the 100 degree, add a drop of flux, pop them in place and a small waft of heat from the micro flame and they were fixed. The water gauge was treated in the same way. a small blob of 100 degree solder applied to the pin pop in place then waft with the flame until the solder melts and the castings sits down in place. If it moves out of position it’s easy to reheat and adjust with tweezers.

MOK 8F 8425 – Mystery Part

A little discovery here, having made the replacements parts yesterday afternoon was all about fitting them. Besides fitting the castings I started to fit the small pieces of etch that represent the backing plates for the rear steps and those just above the foot plate on the rear of the tender.

MOK 8F This is where it fits

Once I had added them I noted that there was quite a big intermittent gap along the bottom. I read and re-read the instructions and couldn’t see where I had gone wrong. There are not too many bits of etch left and one of them that I couldn’t find a home for is part 146. After much head scratching I worked out that although completely omitted from the instructions it fits as outlined in red on the image below.

MOK 8F Part 146- Not mentioned in the instructions

This is on the top side of the tender footplate (thankfully at this point I had only retained it by the tabs so it was easily removed). As if omitting it from the instructions wasn’t bad enough, there are no positive locating marks and in this photo I have it slightly too far towards the tender rear so I need to take it off and move it back a touch or the tender body won’t sit down and close the gaps.

What was I saying about soldering allowing you to take it off and adjust it…

MOK 8F now to be finished as 8425 – Tender casting replacements

Wow, 2018 since I last looked at this. No wonder Chris is muttering.

Any way I picked it up again yesterday and I started by making a couple of replacements for castings and turning the tank vents so that they at least sit flat and vertical to the tender top plate.

MOK 8F Whitemetal castings

These are the water scoop dome and brake cylinder. The latter is oval in shape and the former quite badly pitted.

MOK 8F Replacement turnings and cleaned up vent pipes

Replacements machined and since this photo was taken fitted.

Tender Skin…..

This is what it looks like with the overlays on the body. You get two options included in the kit either welded or riveted. I chose riveted because it adds a little more to the character.

LNER 06 (MOK 8F) Tender Top – Outer Skin

LNER 06 (MOK 8F) Tender Top – Outer Skin

LNER 06 (MOK 8F) Tender Top – Outer Skin

These latter two show the front bulkhead now it’s fitted and the fire iron tunnel which fitted perfectly.

LNER 06 (MOK 8F) Tender Top – Outer Skin

LNER 06 (MOK 8F) Tender Top – Fire Iron Tunnel

More tenderness from MOK.

Before going any further I started to make up the bulkheads which are made up from multiple layers. Here the instructions (or my interpretation of them) let me down again and I managed to get the overlay for the top of the front bulkhead out of sequence meaning that I had to cut a section out of it to prevent having to undo a lot of work meaning that it sits around the lockers not behind them (it was quite easy to do with scissors due to it being half etched). It isn’t visible in the end result but I know I had to do it.

Front Bulkhead

LNER 06 (MOK 8F) Tender – Front Bulkhead

LNER 06 (MOK 8F) Tender – Front Bulkhead

Fire Iron Tunnel

LNER 06 (MOK 8F) Tender Top – Fire Iron Tunnel

LNER 06 (MOK 8F) Tender Top – Fire Iron Tunnel

A Tender MOK moment (more like 3 days work actually!)

A few days off over Easter saw me make further progress on the 06.
Shaping the curves of the inner tender sides was interesting because in my ignorance I had chopped off one end of the etch which contained the marked etched bend lines and although I still had the piece that I removed I couldn’t realistically realign it. So some careful measuring was in order.
I annealed the tops of the sides where the main bend was to be – I did this a couple of times during the process.

LNER 06 (MOK 8F) Tender – Bending the Flare

LNER 06 (MOK 8F) Tender – Bending the Flare

LNER 06 (MOK 8F) Tender – Bending the Flare

LNER 06 (MOK 8F) Tender – Bending the Flare

In order to bend the front curves of the tender sides which were very close to the half etched line for the location of the front bulkhead I soldered in a couple of strips of scrap to stop it bending on the half etched line instead of where I wanted it to.

Once happy I soldered in the rear bulkhead and started to add details.

LNER 06 (MOK 8F) Tender Top

An update on LNER 06 Progress

Although I have made some progress on the chassis, recent minor surgery on my toe has left me struggling with the time/energy to give this the thought that it needs to get the motion assembled so I have been doing a few small jobs on the J6 until my energy returns

LNER 06 (MOK 8F) – Springs sand boxes and steam pipe

LNER 06 (MOK 8F) – Springs sand boxes and steam pipe

LNER 06 (MOK 8F) – Springs sand boxes and steam pipe

Now it Looks Like a Loco!

Further work over the weekend has seen it start to look like a loco at long last.

LNER 06 (MOK 8F) – Upperworks looking like a loco

LNER 06 (MOK 8F) – Upperworks looking like a loco

LNER 06 (MOK 8F) – Upperworks looking like a loco

LNER 06 (MOK 8F) – Upperworks looking like a loco

At the moment all except the cab, the reversing lever and it’s housing are just sat in place and are held by the firm fit of the components. – The sand shields are just lent in place because I need to drill them yet for the sandbox fillers. I am slightly surprised that they don’t have at least some semblance of a hole etched in them given how well everything else is portrayed.

I also need to drill and put a self tapper in the top of the cab face of the firebox to close up the very slight gap on the drivers side before I solder it in place. The instructions suggest doing this but I thought that I had got away without the need until I put everything in place.

Mind the Gap

Mind the Gap, the age old saying on the railways.
Mine was a little more fundamental – the curve of the footplate under the cab was not anything like the curve of the cab sides

LNER 06 (MOK 8F) – Cab Subframe issue

LNER 06 (MOK 8F) – Cab Subframe issue

LNER 06 (MOK 8F) – Cab Subframe issue

Because I didn’t have the benefit of the updated instructions that Mark kindly shared with me after and enquiry over on Western Thunder (I have emailed Dave Sharp to ask for a set of the updated instructions) I had previously added the cab front overlays and soldered all around the seams. This meant that tucking the front of the curved section up under the top layer of the cab front as advised in the updated instructions wasn’t to my mind – I worked on the theory that if I tried to remove the thin overlay I would irreparably damage it.
That left the alternative which was cut/file the front section down so that it sits just below the footplate rather than tucked in behind the front plate and to desolder and file down the sub frames until the curve better matched that of the sides of the cab.

LNER 06 (MOK 8F) – Cab Subframe issue

As you are looking at it, it took two goes at desoldering, filing down, before resoldering to test the fit for the left hand subframe and six goes for the right hand subframe.  At each desoldering I carefully cleaned up before filing a little more off. You may wonder why I resoldered at each test, it was because I couldn’t hold it in close enough proximity to accurately check the fit when trying to hold all the parts while they were
I have to say that had I continued with the build to this point when I started back in 2011 or so, I would never have had the confidence to desolder and resolder the same part so many times to get the fit that I wanted. I would never have been happy with it either.

LNER 06 (MOK 8F) – Cab subframe – modified to fit better

LNER 06 (MOK 8F) – Cab subframe – modified to fit better

LNER 06 (MOK 8F) – Cab subframe – modified to fit better

The slight gap on the right hand in this view will close up when I solder it all in but I am triple checking all is right before taking the final step.

Get out of jail free – or that’s what it felt like.

Although there are glaring gaps in the instructions, one part is explicit, that of forming the smokebox and boiler. 

The boiler comes pre rolled and according to the instructions so does the smokebox inner but mine wasn’t. That wasn’t an issue and I soon had it rolled. 

Now for the ‘I’m a dummy’ bit, the instructions are quite explicit about using two of the formers for the x71 and x72 (sorry I can’t remember if the preceding number is 1 or 3). Leaving x70 to go in the smaller end of the boiler. Because they all look identical (but aren’t Grrr) I managed to pick up the wrong one and only discovered my error when I had it all nicely soldered together.

My only saving grace was that I discovered the error (part x70 is slightly bigger than x71/x72) before I soldered the other wrong bit (x70) into the smokebox). At 11:15 on Tuesday night I didn’t have the headspace to sort it out so I went to bed.

This morning I set to and using a pointed scalpel and gentle heat from the micro flame I slowly worked my way around easing the boiler away from the former with regular quenching to take it out and replace it with part x70.

Thankfully I got away with it, in part I think due to the fact that I had soldered it in initially using the microflame to chase around a tiny amount of solder which meant that although it was held very securely it was easy to break the bond from the thin layer of solder. 

This is the boiler and smokebox assembly after my recovery.

LNER 06 (MOK 8F) – Boiler and Smokebox

Those with sharp eyes will not the piece of scrap protruding from the front of the smokebox.


LNER 06 (MOK 8F) – Boiler and Smokebox

There is a clever bit of the etch designed to ensure that you get everything lined up by inserting a piece of scrap into a slot etched into each of the three forward formers

LNER 06 (MOK 8F) – Boiler and Smokebox

I left it longer than suggested and used it to view down through all the apertures in the boiler top. In fact I left it in place as I soldered on the castings on top of the boiler. To solder these cleanly I flattened a couple of small bit’s of 145 solder in some pliers, placed them either side of the chimney opening after using a taper broach to open the hole up to take the spigot from the casting as tightish fit. a squirt of flux and then I place the chimney on top ensuring that it was square I heated the casting with the microflame until the solder melted allowing the casting to sink into place. – Repeated for the next casting (which I have to be honest and say I have no idea of the name or purpose of it).
At this point the Firebox, boiler and smoke box are all a nice tight push fit I won’t make it more permanent until I am happy with everything.
Finally, I had fitted the cab roof on Tuesday but I still need to sort out the subframe under the floor.

LNER 06 (MOK 8F) – Cab Roof

LNER 06 (MOK 8F) – Cab Roof