Crymlyn A Shop Techniques. Barry Railway F Class.

davey4270

Western Thunderer
120. Fitting the Boiler. Part 4.


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I have attached a copy of the instructions to give you an idea of what’s involved! I attempted to assemble the frame extensions which were too short, the wrong profile and lacking any rivet detail. In fact they were as much use as a chocolate tea pot. Although I have seen these for sale in my local motorbike shop. Perhaps a novelty Christmas present. I guess they’re something I’ll have to scratch build later. That’s the frame extensions not the chocolate tea pot.


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This picture is of the smoke box front and saddle. The side plates had to be cut to length and curved outwards at the top but the rear plate was accurate. I curved the plates by placing one in a vice with the jaws slightly open and bending the plate slightly, move it 1mm and bend again etc just like forming the bunker rear plate. See earlier blogs. When you’re happy with the profile, solder in place with the rear. I folded up an inverted “L” shaped piece of scrap brass and soldered it across the lower front.
The next job will be to drill 2 holes for 12 BA screws from beneath the footplate and through the “L” shaped bracket. This will have 2 x 12 BA nuts soldered on top to secure the smoke box/boiler to the footplate. The circular boiler former soldered to the inside of the smoke box front is clearly seen. This accurately locates the front of the boiler and it will be soldered in place later.
 

davey4270

Western Thunderer
121. Fitting the Boiler. Part 5.


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This picture shows the smoke box saddle and front with a pair of 12BA nuts soldered to the previously fitted bracket. 2 screws passing upwards through the footplate will securely hold this to the footplate but allow it to be removed for painting. Also visible are the first 2 holes I drilled which, unfortunately, were too close to the chassis frames which fouled the cheese head screws. I unsoldered the nuts and drilled 2 new holes a few millimetres closer to the centre having to drill new holes through the footplate as well.


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The inside of the cab showing the 2 screws serving the same purpose holding the firebox in its etched groove on the outside of the cab front.


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I have yet to solder the boiler tube to the smoke box front plate as it is merely located on the circular spacer which is soldered to the inside of the smoke box front. By removing the 4 screws, the boiler/firebox/tank assembly will be removable making painting the model significantly easier. The next job is to check that everything is in the correct position and square, then I will solder the cab to the footplate as it is only tacked in position at present.
 

davey4270

Western Thunderer
122. The Tank. Part 1.


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As mentioned earlier, the tank formers are horse shoe shaped and wrap around the lower part of the tank. Quite how the tank would have been removed from the prototype, if it was designed like this, I have no idea. The tanks were usually bolted to brackets attached to the smoke box and at the side of the firebox. From prototype pictures and the scale drawing there are 3 pairs of support brackets along the length of the tank. These appear to be supplied in the etch but no mention is made of them in the instructions. Prototype pictures also show 4 lifting rings fitted to the upper part of the tanks so it was obviously designed to be lifted off.
I modified the shape of the tank spacers to allow this. The upper former in the picture is as supplied and my modified version is below it.
To get some uniformity with the spacers, I modified the first one and clamped it together with the others in my vice and gently filed them to the same profile.


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I had attempted to roll the tank wrapper with a dowel and various layers of soft paper on a carpet without making much headway. I then remembered reading an article in an old Model Railway Journal where, I think it was Guy Williams, it was suggested to roll it against your thigh. Oh well, I thought, nothing to lose and it worked perfectly! More fine adjustments later and it is as close a fit as it’s going to be.
The formers are a trifle flimsy and bend far too readily when trying to fit them and also flop about when sitting on top of the boiler.


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I had an idea to make the formers more rigid and drilled a hole to take some 1.5mm N/S rod near the bottom of the formers. There is a tab and slot where the formers sit on the boiler and the same arrangement where the tank wrapper sits on top of the formers. I aligned them on top of the boiler as squarely as I could and soldered the rod to the formers. How on Earth did we manage before they invented blutac? I did not use brass tube on the bottom to bend the tank wrapper around as it is already formed.
Hopefully this will make a more rigid frame to solder the tank wrapper tomorrow.
 

davey4270

Western Thunderer
123. The Tank. Part 2.


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A quick check of the tank wrapper against the boiler showed that the location slots for the tank formers didn’t align very well. The slot in the tank wrapper between the 2 rows of rivets left of centre is at least 1 centimetre out from the slot in the top of the boiler. I aligned the slot to the right of centre with the corresponding one in the top of the boiler and the rear slot is about 5mm out!
As I’d aligned the spacers to the slots in the boiler, I cut off the top location tabs on top of the formers.
I aligned the rear former with the back of the tank wrapper and tack soldered it in a few places. I also tacked the other 2 formers to check the tank’s shape and alignment.


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I had to remove about 2mm of the inner edge underneath the tank to clear the boiler as the tank wrappers were as wide as the original profile of the spacers. With this done the tank can be slipped over the boiler and kept in position by the tank spacer locating tabs. Some minor adjustments are required at the front to square up the smoke box front/saddle before the half etched tank front can be fitted above the smoke box. Once I’m happy with the adjustments the whole unit can be soldered together.
 

davey4270

Western Thunderer
123a. The Tank. Part 2a.

I haven’t been able to devote much time to the model recently and probably won’t over the next few days. But I’ve managed to find the problem with alignment at the front of the tank. The picture, looking down from above, shows at the top a silver square aligned with the side of the footplate. At the bottom can be seen the front of the tank wrapper and at a slight angle between these is an out of alignment smoke box front.
Hopefully the solution will be to make the locating holes in the footplate for the smoke box component into slots so that the component can be straightened and moved towards the tank wrapper. I will also need to remove up to 1mm from the front of the boiler tube for the smoke box to align with the tank wrapper. I will check for this after realigning the smoke box component.

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davey4270

Western Thunderer
123b. The Tank 2b.

Further investigation into the misalignment at the front found that the holes in the front of the footplate for the smoke box securing screws needed to be moved slightly forwards. They were too far back and on tightening the screws were pulling the front of the smoke box into the footplate and tilting it forwards. Elongating the hole using a suitable size drill bit (1.5mm) as a file did the trick. The boiler tube was fractionally longer on the L/H side so I removed about 0.5mm from this side squaring up the front. The tank still needed to be moved forward about 1mm and as the front boiler former was very close to the front of the tube this would have meant resetting it further back. I chose the easy option and elongated the tank locating slots in the top of the boiler. Only part of the rear one on the top of the firebox will need to be filled as the others are hidden underneath the tank.
The next job will be to fit the half etched tank front/former inside the front of the tank.

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davey4270

Western Thunderer
123c. The Tank 3.

This has turned out to be a nightmare! The person who designed this kit either never built one or couldn’t be bothered to modify it!


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I managed to solder the tank front half etched overlay in position. This was not an easy task as the overlay was too small to fit on the front of the tank and a tad too big to fit inside. I had previously checked it against the other tank formers and it was just slightly bigger which cleaning up the etch marks should have corrected. The fact that it was half etched and weak made fitting it a major problem. Perhaps with hindsight another tank former to solder it to would have been the answer.
Anyway, I finally got there and fettled the tank to sit at the very front of the smoke box face plate.
Next comes the 2 tank overlays. These are again half etched and I have started to shape them as seen in the above picture. The overlays have central holes in them that correspond to holes on the boiler barrel which, I guess, represent the chimney and dome mounting points. My thoughts that these locomotives were cobbled up from spare parts left over in the workshop is further supported by the uneven spacing of the tank plates.


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This is an enlargement of 726’s tank and the uneven plates can clearly be seen. Also visible are some larger rivets between the plates that probably were attached to the tank framing. Again, these are unevenly spaced from the tank plates. For once the alignment holes in the etched overlays place them in the correct positions.
The next problem is how to solder the etches in position without making an unholy mess on the tank body. Tinning and applying heat might work but would be messy so I’m thinking of using some solder paste I have with an extremely low melting point. 30’C to 60’C is quoted and this can be spread like butter, held firmly in place with rubber bands and melted with either a hair dryer or boiling water. I would do a proper solder job on the underneath of the tank to secure it. Both these plates have handrail knobs through them which would also pin them in place. I have a picture of one of these models assembled and these plates are omitted.
Obviously I won’t be able to clean the model using very hot water.



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I finally got around to soldering the cab permanently to the footplate. After checking alignment of the boiler/tank/cab front was correct, I joined the dots, so to speak, fully securing the cab to the footplate from the inside. I also tack soldered the smoke box front to the boiler tube. I did this while the smoke box was firmly screwed in position to the footplate and against the boiler tube to ensure correct alignment.


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A view of the bunker rear from the outside showing that almost no cleaning up is required. The solder on the inside will not be visible so doesn’t need cleaning up except, perhaps, a small spot where the rear spectacle plate will touch the floor becoming the cab rear.
 

davey4270

Western Thunderer
123d. The Tank 4.

So much for my ideas on attaching the boiler half etched plates! The solder paste wasn’t interested even with the attentions of my 40W iron and I tried a coat of varnish underneath the plate but after 2 hours that hadn’t stuck. So, it was back to plan B and soldering it.


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After forming the overlay closely to the tank profile I smeared a layer of flux where it would be positioned and painted the rows of rivets with Carr’s metal black for brass. This will stop any solder from spreading over the rivets. I centralised it with a cocktail stick through the hole indicating the chimney’s position and carefully bent the ends of the etch around the bottom of the tank securing it with a few rubber bands. Checking that it was inline with the front of the tank, I tack soldered it either side at the centre. Pressing it firmly against the tank, I tack soldered it every 1/2 inch or so continuously checking its alignment. I used my 25W iron for this and when I was happy with everything, worked around it with my 40W iron which joined the dots, so to speak, with the flux drawing much of the solder between the plates. I still have to file the front of the tank wrapper and overlay back to the tank front etch, about a hair’s breadth, and the solder visible at the back of the etch is really more of a stain but will be attended to further after the other etch is affixed.
The metal black stains on the etched plate have mostly been removed by a quick scrub with “Shiny Sinks”, a toothbrush and hot water.


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The detachable boiler to which the tank will be soldered is easily removed to make painting easier.
 

simond

Western Thunderer
some solder paste I have with an extremely low melting point. 30’C to 60’C is quoted

this seems extraordinary, I have never heard of such low temperatures for soldering. What is it?

Typical low-melt would be around 70C, and that won’t normally wet brass, so it’s necessary to pre-tin to get a bond.

atb
Simon
 

davey4270

Western Thunderer
this seems extraordinary, I have never heard of such low temperatures for soldering. What is it?

Typical low-melt would be around 70C, and that won’t normally wet brass, so it’s necessary to pre-tin to get a bond.

atb
Simon

Hi Simond,
This is the paste which clearly states the temperature that it melts. I have also heated it well above that temperature with a soldering iron and it does melt but returns to a paste when it cools! Perhaps I'm doing something wrong but I did Google it and it said to use UV light???
Anyway, I think the soldering was reasonably successful so will attempt the larger third panel soon.
Regards,
David.
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michael080

Western Thunderer
Hi there, Duratool d01852 seems to be Flux rather than solder, it contains ZnCl2 as active ingredient,

Michael
 

daifly

Western Thunderer
This product (185 300) is listed by Squires on p235 of their catalogue:
"SOLDER FLUX PASTE a small metal tin of 30g of solder paste for use when soldering to avoid dry
joints through oxidization."

Dave
 

davey4270

Western Thunderer
This product (185 300) is listed by Squires on p235 of their catalogue:
"SOLDER FLUX PASTE a small metal tin of 30g of solder paste for use when soldering to avoid dry
joints through oxidization."

Dave
So presumably there's no actual solder in it and that's why it doesn't work!
 

simond

Western Thunderer
At £2.50 for 30g, it would be a bit cheap for solder too!

I’d say the container labelling is somewhat misleading but my bet too is that it is flux, though I can think of no reason why you’d care about its melting point, presuming it’s less than that of the solder, of course.

Anyway, you’ve done a nice job of the overlays, which were presumably being soldered to very clean metal...
 

davey4270

Western Thunderer
123e. The Tank 4.


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Fitted the same way as the front overlay, the “central” one is central to nothing. Using the dome position holes gives an accurate alignment for this panel as compared to pictures. One of the tank former slots, there’s another visible just to the left of centre, is hidden underneath this overlay so this will save one filling job. I painted the row of rivets at either side of the overlay with Carr’s metal black for brass to prevent solder filling them and cleaned the inside of the overlay along with its position on the tank. I had previously curved the overlay to the approximate shape of the tank and smeared some flux underneath each side of the overlay. With a cocktail stick through the alignment holes, I positioned and secured it with several rubber bands. I checked the folded parts of the overlay underneath the tank aligned and tack soldered them in place to prevent it moving. I then tack soldered the top centre in place at either side pressing the overlay firmly to the tank body using my 25watt iron. After checking everything was still straight, I tack soldered it every half inch or so as seen in the picture.


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Firing up my 40 watt iron I reheated the “tack” which ran most of the solder blobs in between the overlay and the tank by dragging it towards the next blob each time. Take some time doing this as too much heat in one place could distort the tank. Finally I filed off the excess overlap inside the underneath of the tank to clear the boiler.
A quick clean up with a file and a scrub with shiny sinks, a toothbrush and hot water has improved things significantly leaving more of a stain on the brass rather than traces of solder.


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A cropped close up of a rear 3/4 view of 779 shows that the “frame extensions” as suggested in the rather meagre instructions were the top of the main frames and actually ran the full length of the footplate to the cab and possibly beyond. The addition of this feature to the model will help to fill the gap between the splashers and the firebox. The Crymlyn A Shop Forman has subsequently approved an order for these with preferred sub contractors Minerva Engineering.
 

simond

Western Thunderer
Davey,

I think I’d be considering firing up the gas torch, which, with a goodly dose of that flux you have, should get the solder under the overlays. I’d probably use soft iron wire (local florist) to hold everything in place.

then again, if it’s ok as it is, maybe discretion is the better course...

atb
Simon
 

davey4270

Western Thunderer
Davey,

I think I’d be considering firing up the gas torch, which, with a goodly dose of that flux you have, should get the solder under the overlays. I’d probably use soft iron wire (local florist) to hold everything in place.

then again, if it’s ok as it is, maybe discretion is the better course...

atb
Simon

I don’t think Sue would approve of me using the gas torch (her gas cooker) for this purpose!
Seriously though, the 40W iron produced flux vapours and most of the solder disappeared everywhere it was applied so I think it’ll be ok.
 

davey4270

Western Thunderer
123e. The Tank 5.


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I spent some time aligning and squaring up the tank. I used blobs of Blutac at first measuring the gaps between the tank and footplate with my Vernier. This wasn’t easy as the overlays wrapped underneath the tank are at least 0.5mm thicker than the uncovered parts. Eventually I got it to my satisfaction and a solder tack on top of the smoke box and firebox held it firmly in position.
Pictures I have of the prototype show various designs of tank supports on the sides of the smoke box but the other supports from the boiler are largely invisible. On the smoke box these vary from a heavy duty type with side fillets much like a pannier tank, a similar type without the fillets but with several large bolts, a similar type welded or with flush rivets and one that must have been attached under the tank like an “L”. The kit correctly supplies 6 brackets with a pair of larger ones for the smoke box but no rivet detail on them. My chosen prototype appears to have the welded type so I simply soldered the smaller part of the now folded etch to the smoke box but not attached to the underside of the tank.


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The other 4 bracket were soldered in position, again only to the boiler, which will hopefully give a solid location for the tank. All the brackets were folded to an angle somewhat over 90’ to suit the location with the boiler curving away from the flat underneath of the tank and held against the underneath of the tank while soldering to the boiler. I wish to solder some detail, like hand rail knobs, from the inside so the tank will be firmly attached later.
 
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