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David's Workbench

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David Holman

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Thanks Eoin. Have been using Humbrol Liquid Poly for many years. A bit fierce for some tasks [and smelly], but certainly does the job re microstrip and perspex. Check out Peter Smith's latest book on using printed papers. He's the man behind Kirtley Buildings. Called Using Printed Papers in Railway Modelling; ISBN 9781505358476. Got mine from Amazon & whilst I don't agree with everything in there, it contains much of value & interest.

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  • 1 month later...

Ariana Town's fiddle yard has 7 tracks, six of which are now filled. The final track has long been reserved for Sir Henry, the SLNCR 'large tank', which I fell in love with courtesy of Neil Sprinks photo album of the line. Two things have put me off making a start, one the loco has to be a scratch build and with at least as many rivets as a small tank, is certainly no easy undertaking. Second, it was deciding on a train for it. I already have too many wagons, but didn't really want to add another freight train to the operating sequence. Looking through the Sprinks album once again gave me the idea of a short passenger train, made up of coach 10 or 11, plus a six wheeler and the parcels van I built last year. Alphagraphix do card kits of the coaches, so I've ordered a couple & finally decided to grasp the nettle on the loco. My CV now runs to well over 50 locos & though many are etched brass/nickel silver kits, I've only previous done two all metal scratch builds. Little and large, one is the Wantage Tramway well tank and the other a D16/3 [Claud Hamilton] 4-4-0. Plus, both were a while ago now, so it all added to the procrastination...

However, the modelling season is upon us & creating a complete train seemed like a nice winter project - though it will probably take up autumn and spring as well. A starting point exists in that the Manchester Museum of Science & Industry holds a collection of Beyer Peacock drawings & I bought one a while ago and got as far as creating a basic outline drawing in 7mm scale. This was necessary because the BP one is a general arrangement [GA] drawing - a bit like a X-ray of the loco, showing much inside detail. Basic dimensions are also in the Sprinks history of the line, showing 4'8 16 spoke drivers and 3'0 bogie wheels. These are on order from Slaters, though there was an early issue in that the wheel spacing is 6'7+ 4'11. This means there is precious little space between the rear pair of drivers, so I've changed the spacing to 6'6+5'0 because there was every chance that the flags would be touching otherwise.

Another problem is that there appears to be no source of coupling rods of this size, which is a shame, because rods are very time consuming to make and Premier Models do a very nice range of profile milled rods - but none that are anywhere near my needs. Also a pity, because I was tempted to build a sprung chassis, requiring jointed rods, but in the end chickened out and made a solid pair. These are very much the starting point for any loco chassis as by making the rods and them clamping them to the frames for drilling, there is a good chance that a smooth running loco will result.

So far, have spent the last two days making the rods from 1.5mm brass strip, overlaid with a thin strip of 'fluted' brass. Nickel silver frames have been cut from 22swg & all in all this is not a quick process. Thin brass/nickel silver can be cut with strong scissors, but thicker stuck needs piercing saw, though I often cheat and use a slitting disc in the Dremel for longer cuts.

A long list of castings/fittings is being prepared. I don't have a lathe, or indeed know how to use one, so am hoping there will be something suitable for the all important chimney & dome. At least I have a nice domed smokebox door in the spares box, otherwise a visit to the GOGuild Trade Show at Reading in December will help fill the shopping list.

The photos show the loco, a section of the GA drawing and the start made with the rods, so watch this spaceDSCN1550.jpg

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Much as I would like to extend, experience has taught my my limits in terms of exhibition layouts. Plus it was built to fit in my workshop and I don't have any storesge space for more boards. That said, I could well do a couple of diesels - C, 121, G etc, so there is still some mileage in the layout.

Further ahead, a kit of the Clogher Valley Sharp Stewart tanks is being released soon and I've always liked the railcars...

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Around 4 days [probably getting on for over 20 hours] work has got a rolling chassis completed for Sir Henry. Helped very much by Slaters and the Royal Mail - put in an on line order for the wheels and bearings on Friday morning & the parcel was waiting when I got home from town on Friday morning.

I had a few frame spacers left over from the Small Tank kit [now with Studio Models], plus a couple of spare buffer beams too, so the former were very useful when setting up the side frames. I used some 3/16" rods through the bearings to ensure the two frames were square, then added additional pieces that I cut myself afterwards. Hazlewood and Fermanagh form useful references for each stage of this project & I'm pretty much following the same order of construction. If it works...

Anyway, this morning was able to assemble the wheels, drill out the coupling rods to 2.5mm and then [with more than a degree of trepidation] see if the chassis would roll. It was a bit tight at first, but this is not because of the rods, but the rather short crankpin throw on these wheels. The only 16 spoke ones available close to scale 4'8 are 4'7.5 for a GWR 2271 pannier tank. The throw is only 10", which means the 10BA crank pin bolt head fouls the frame bearings. Out with the Dremel again to grind a bit off each bearing. Guess I could have counter sunk the bolt heads, but in the past I've found this can reduce the strength of this joint. Anyway, all seems well and the chassis rolls very smoothly with just light finger pressure. Always a very satisfying moment in loco construction, 'cos if it doesn't work at this stage, then a lot of fettling can result before you get a good runner.

One other thing to note from the pictures is the small gap between the two rear drivers - just as well I stole an inch on the frames - and indeed another inch on the drivers - or they would have been perilously close.

Next step will be the footplate, then I can add the rear bogie. Happily, the Gladiator Models bogie equalising kit is the original from the Northstar - it still has their logo etched on it!

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Nice to see a scratchbuild, the SLNCR 0-6-4Ts with their short coupled wheelbase and firebox behind the trailing axle almost seem to be a development of the long boiler type of locomotive used on the NER.

 

The short coupled wheelbase would have been easier than a conventional six coupled tender or tank loco and the bogie would have improved stability compared to a long boiler 0-6-0.

 

Look forward to seeing more of the build.

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Thanks John. Several people at shows have suggested the Small Tanks were long boiler types and looking at them it is hard to disagree, even though the design must have been very outdated by then. There again, there were described as primaeval!

Though the wheel base of the Large Tanks is a different spacing, overall it is the same as the small ones and the more I study them, the more Similarities emerge.

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I always had a soft spot for the "Large Tanks" a tin plate model based on a photo of Lough Gill was my first "scratch built" loco that actually ran. The body was glued together from soft drinks tins, the chassis was from a second hand Triang-Hornby Princess bought for £1 re-wheeled with Jinty wheels it waddled but at 16 or 17 was my pride and joy and only working loco.

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Sounds splendid John. When I joined the Chatham Club in the late 1980s, the Doyen was a lovely man called Tony - a genius with tinplate. His favourite medium was empty Castrol GTX oil cans. One of his now legendary exploits was in bringing a drawing of a LSWR B4 0-4-0T down the club one week and a completed model of it the next - all cut from GTX tinplate. He also favoured 20-50 motor oil to lubricate the mechanisms of his locos, applied by hypodermic syringe - his was was diabetic. This was towards the end of that era when if you wanted anything out of the ordinary, you built it yourself.

If I was starting again, then maybe I'd be sticking to RTR, but there is much satisfaction in creating something from scratch and happily the Irish scene still provides that opportunity.

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  • 2 weeks later...

Slow progress this week, due to other commitments. However, have managed to cut out a footplate, adding 2mm brass angle for the valances, plus spare buffer beams left over from my 'Small Tank' kits.

Since then, have been experimenting with 10 thou brass for the tank and bunker sides. Like the small tanks, Sir Henry has hundreds of rivets. Was thinking that I would have to do some serious marking out to create them. However, then remembered that my GW Models rivet press, has a spacing table, which enables you to mark out rivets easily, with spacings down to 1mm or less. The first couple of attempts went a bit awry, but these will form the inner tank sides. The third attempt is good enough for one of the outer sides, so now need to get the second one done. Have cut out the pieces for the bunker sides/end, plus the tank fronts, so a fair bit of riveting is now required. unfortunately, the photo of the rivet press is too big to post, so will have another go & update soon.

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In engineering terms, it borders on heresy, John. Am using 10 thou brass, so it can be cut with strong scissors. Do the same with 15 thou [likewise nickel silver], but anything over that means the fret saw. Really don't like it much, as it takes so long, which was why the frames and rods took so long to make. However, am not above using a slitting disc in my Dremel. Needs care, but much quicker! In each case, cut as close to the marked lines as I dare, then clean up with files.

The 10 thou brass is probably a bit thin for 7mm scale, so am reinforcing it with scrap strips and/or L shaped angle as appropriate.

Definitely recommend the rivet press. Well engineered from mild steel, have had mine for several years & though it doesn't get used a lot, it is one of those tools I would not be without.

Edited by David Holman
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Seems there are no rivet counters out there at the moment - or more to the point 'lines of rivets'. Thought I finished the horrendous job of doing the tank sides, only to find I'd put five panels of intermediate rivets instead of six...

Reaction was fairly muted for once, though the word that rhymes with what rowers put their oars in was uttered at least once. However, had been increasingly feeling that the 7mm scale 'anvil' was producing rivets that were too big. So, out with some more brass sheet and spent much of the day making new tank sides, which [to my eyes at least] look neater.

Probably also said something that rhymes with rugger too - though much of that and more was reserved for Saturday's debacle. No, not against the Aussies - they were just too good, it is the Wales match that rankles. So, must now transfer my allegiances to Ireland [of course, you say], though the Haikka is still my favourite piece of sporting theatre.

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Spent the last few days going squiffy riveting. The GW Models press is superb for getting evenly spaced rivets, but still requires care setting up or you soon find the lines aren't as parallel as you'd wanted. Hence had to do a couple of pieces again, while the initial sides also had to be re-done because I got the spacings wrong... At least the rejects will serve as the inner tank sides, so not completely wasted.

So, with well over a thousand rivets to do on the sides in the first place, I've probably almost doubled that. Not recommended. However, at least now have a basic set of parts to do the tanks and bunker - as you can see in the photos. Have included one which shows the difference between using the 7mm anvil in the press [at 1.5mm intervals] and the 4mm one at 1mm intervals. much neater methinks.

The other picture is of the cab front sheet. Did this out of thicker brass, with the window surrounds done by soldering a 10 thou blank over the initial hole, the drilling & filing back. A fiddly trick taught me several years ago by Laurie Griffin in his MRJ scratch build of the Wantage Tramway loco 'Jane'.

The next step before assembling the parts will be to solder stiffening strips to the back of the parts, some of which will be placed to help locate bunker and tank tops. A chance to get out the RSU [resistance soldering unit], so will hopefully show you how that works next time.DSCN1606.jpg

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Every time I think I'm ready to start putting pieces together, I realise there is something else that needs doing first. However, this is the additional challenge of scratch building - though there are kits where it can pay to see what additional detail may be needed too.

In the case of Sir Henry, realised that though I'd made the outer parts of the cab, tanks and bunkers, I hadn't sorted out how they fitted with the inner pieces, hence some further cutting and riveting required. In addition, because I'm using 10 thou [0.25mm] thick brass for the tanks and bunker, these need some reinforcing to keep their shape. Found some thicker brass strip in the scrap box and after tinning it first, got my truster RSU out to attach to the sides. Got mine several years ago, but I think Swanage Models may still sell them. Comparable in price to a temperature controlled unit, so not cheap...

For those who haven't come across this, a resistance soldering unit works in a different way to a conventional iron. As you can see from the pictures, it comprises several parts - the main power box, a metal plate, a carbon probe and a foot switch. The probe and metal plate have leads which are plugged into the power box. This has several sockets to give different outputs, from 1 volt to 4.5 volts. Doesn't sound much but the higher outputs can literally vaporise small items if you are not careful!

In this instance the cab/bunker rear is laid on the metal plate, then the reinforcing strip [already tinned & fluxed], placed in position. The carbon probe is pressed on the latter, which holds it in place and then the foot switch is used to apply power. Heating is almost instantaneous. Foot off the switch and hold the probe in place till the solder cools & job done. Not applicable for all soldering jobs, but very useful for some, including adding fine details/overlays etc - as long as you turn the power down.

Photos also show the assembled bunker & cab rear on the footplate. Would like to say this didn't take long, but made a mess of the cab rear initially [not straight or central!] but didn't notice until I had the other parts on, so had to unsolder & start again. Even then the join is not perfect, though at this stage, it is just tack soldered in place till I'm happy with the overall way things sit. Stuff happens [or something like that, as the Bhuddists say] and at this stage of a model it is crucial to get basic alignments correct or it could end up throwing the whole model out of line later. Occasionally have to remind myself, it is not a race. Likewise, always best to stop when you are going well. Doing one more job almost always means you make a horlicks of it & it needs doing again later...DSCN1610.jpg

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The last few days have seen the tank sides soldered in place. Eight pieces in all - outer & inner sides, plus front and rear sections. These were assembled first, then the cab front was cut to fit in between the two tanks. Also added a top to the bunker, which still needs a further set of sides fitting, plus the bunker front, inside the cab. This should have a hole for the fireman to shovel the coal, but it will be hidden by the crew [once fitted], so have decided to save myself the trouble...

A good wash came next, to clean off the flux [or the metalwork soon goes green] & then it was time to sit back and decide what needed to come next. At the moment, I'm concentrating on getting the superstructure built & will go back to fitting details once the general outline is completed. This was a good time to remind myself that, though the model is taking shape, there is still a long way to go!

To help with painting, have decided to make the boiler/firebox/smokebox unit removable. The boiler is actually the etch from my first Small Tank [Hazlewood]. I'd replaced it on the latter with a piece of copper pipe - right diameter, but almost impossible to solder anything too as it was a thick old bit of metal. Now, a Small Tank's boiler is smaller than Sir Henry's, but most of it is hidden between the longer side tanks. Hence a current gap at the bottom will be covered with a fillet of brass & the joint made good with some judicious filing. Waste not, want not.

As it is you'll see that a mix of nickel silver and brass is being used for the superstructure, simply because I'm starting to run out of sheet metal. The firebox is nickel, I cut two end blanks from 18thou sheet and soldered a ten thou wrapper around them. The second attempt was much better than the first! End blanks for the boiler were also cut from thicker nickel. I used a puch to mark the centre of two circles, then scribed these with a compass, before cutting out with a slitting disc in the Dremel. These were filed to shape with a grinding disc [again in the Dremel], then I drilled through both so I could bolt them together [8BA] and file to shape in my pillar drill. There are centre holes in the fire box front/rear, plus the cab front. This means I can use 8BA nuts and bolts to assemble the boiler/firebox to the cab front. The firebox and boiler were also bolted together, prior to making a solder joint.

As you can see from the photos, the boiler front rests on some polishing pads, to allow me to check alignments. At this stage, everything looks a bit anorexic & I'm constantly remeasuring clearances. Not so much a case of measure twice, cut once, as act in haste, repent at leisure.

Forgot to mention the front splashers. Hate doing these things, even on a kit, as they are awkward soandsos to fit. Use 240 solder to fit the outer faces and 145 solder to fix the tops. These are 10 thou brass. Easy to shape, but finger singeing to fix...

I'm sure you've spotted the dent in the boiler, worry not, it will be covered by the smokebox wrapper, which is the next item on the list.

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Edited by David Holman
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Hi David

 

Excellent progress and workmanship- I'd like to get one of those resistance soldering units sometime...

 

I use a pickle solution in a tall glass jar for plonking the model in overnight after a soldering session, that will stop the green thing happening, it removes the flux, and if you make a strong solution the model comes out shiny n all in the morning. The jar lasts for years- though needs to be kept in a safe place

 

Eoin

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.....I used to use diluted sulphuric acid which is deadly at doing the job- but its deadly so I gave that up.

 

I'm now using 'Pickling Compound' by PRO-CRAFT (can get it at a jewellery supplies outlet), its Sodium Bisulfate granules that you mix with water. A 1.14kg tin has lasted me 20 years and its not half empty yet, I make up about 2 pints of water with 12oz of the stuff for a week solution, most supplier have options

 

Here is a link to a small jar but you should get bigger;- https://www.etsy.com/uk/listing/248366953/pre-po-pickle-compound-3oz-45100

 

Eoin

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and

 

I'm playing about with acids to blacken my etched brass Dart boige frames- while researching on the web I found a guy that claims vinegar in a water and something? mix will blacken brass! I did try malt vinegar on its own which dulled the brass in about 4 days, I must get the stuff he mentioned and try again... so stay away from vinegar unless it for your chips

 

Eoin

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Re recent chat on cleaning/blackening, I've bottle of Birchwood Casey Gun Blue which I've been using for years as a blackener. Better than the Carr's stuff in my experience - I believe it is essentially selenium dioxide. Applied with a cotton bud, it works in seconds and is neutralised with tap water. Works a treat, but never tried it on chips...

Sir Henry has progressed quite well to the smokebox phase. The latter is essentially two layers of 10 thou brass, the top one riveted appropriately. A nickel silver blank was shaped for the smokebox front & the whole unit sits on a saddle made from more 10 thou strip & bits.

At this stage, it seems like the project is going fine, until I made a list of what needs doing. Counting brake gear as 6 separate items for example, there are still over 100 jobs to do & that is before cleaning up, painting & weathering.

By the by ,just been to the Uckfield Show - easily the best of its kind in SE England - where I boughtNorman Johnson's last book 'Parting Shot'. Excellent. Interesting to see that a caption of one photo of the last SLNCR 0-6-4Ts says they were the final incarnation of the classic 'long boiler' locos [firebox behind the drivers], built nearly 100 years after they had gone out of date anywhere else!

Sir Henry might have to take a bit of a back seat for a bit. The Beckenham Show is next week, plus I need to order a few bits/materials to move the project on again.DSCN1619.jpg

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Hi David

 

'Birchwood Casey Gun Blue'

 

Does it work on solder?

 

I've been using Carrs- two types;- one for solder and other for brass. It's not great, it comes out very flaky and when dry it's a powder on the surface, buffing it up leaves a mottled finish! I can live with it but it would be nice to find a better product.

 

Eoin

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Just seen your reply Eoin. Went to the workshop and did a test. Not only successful, but seems to work quicker on solder than clean brass or nickel silver. The effect is almost instant too, whereas brass & nickel need up to 20 seconds before neutralising with water. Like you, I've used Carrs metal black, but gun blue is much better.

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