RMweb Premium DLT Posted May 24, 2020 Author RMweb Premium Share Posted May 24, 2020 (edited) For larger parts, like whole locomotives, we need to go a bit bigger! The component sub-assembly parts of the loco body are shown: front bogie, footplate & cab, cylinder block, boiler, chassis, and motion-plate. Method to follow. Hope this helps, Dave. Edited September 6, 2022 by DLT 11 Link to post Share on other sites More sharing options...
RMweb Premium Popular Post DLT Posted May 24, 2020 Author RMweb Premium Popular Post Share Posted May 24, 2020 (edited) For larger and more complex shaped sub-assemblies a slightly different method is used to achieve the same result. This time I scrub the whole thing vigorously with old-fashioned scouring powder (Ajax/Vim) using an old toothbrush. This way you can get into all the nooks and crannies (well, nearly all) so that no area remains greasy or un-abraded. Once done, I rinse and brush as much off as I can under the tap, and put it straight into the Ultrasonic Cleaner. After a few minutes in there, (its amazing how much more crud comes off) I dry it quickly with kitchen roll and then straight into the blackening fluid. I have a 250ml bottle of Carrs Metalblack for Brass, and I pour it into a jam-jar for the purpose. The jam-jar allows you to dunk half the assembly in for a few seconds, then turn it over and do the other end. I also use a small paintbrush to agitate it and generally brush over any "tide" marks, or areas that are a bit slower to blacken. Then its quickly into water to stop the reaction and rinse off. It goes without saying that once the cleaning is done, avoid touching the metal, or at least the visible bits of the model, the last thing you want is greasy fingerprints on the metal. You will get a bit of black powdery residue on the brass, also a white powder on the solder joints, but these are easily brushed off in the water. Once dried (more kitchen-roll) it should look something like this: Below I have poured a little of the solution into a small container (35mm Slide Case) for blackening long thin components like handrails and reversing rod. I hope this is useful, Cheers, Dave. Edited September 6, 2022 by DLT 7 1 12 5 Link to post Share on other sites More sharing options...
Jack P Posted May 24, 2020 Share Posted May 24, 2020 (edited) Fantastic blow by blow Dave. I don't think it can be understated just how much the blackening of motion/wheels makes a difference. While you're taking requests (!!) I'd love to know how you solder so neatly! Edit: or how/what you use to clean up. Edited May 25, 2020 by Jack P 2 Link to post Share on other sites More sharing options...
bgman Posted May 25, 2020 Share Posted May 25, 2020 Also shows the confidence of the builder with no plug in the sink ! Nicely done Dave. G 2 3 4 Link to post Share on other sites More sharing options...
tender Posted May 25, 2020 Share Posted May 25, 2020 Many thanks for the 'step by step' Dave. I'll have to give it another try. Ray. 1 Link to post Share on other sites More sharing options...
John Tomlinson Posted May 25, 2020 Share Posted May 25, 2020 I've never done a full loco body, but use the technique a lot on small parts, which can allow you to get away without a primer painting coat if they just need a touch of black to finish. Blackening brass wire is especially useful prior to use in making handrails etc. Dave's insistance on cleanliness in preparation is spot on in my experience, the fluid simply won't take if there is any residual muck or grease. Worth also mentioning that "blackening" isn't quite the outcome, you don't get a deep black sheen, but rather a dullish dark grey brownish cover - as Dave's photos of the body show. Very tempted having seen this excellent outcome to try a "full monty" on my next kit! John. Link to post Share on other sites More sharing options...
RMweb Premium DLT Posted May 25, 2020 Author RMweb Premium Share Posted May 25, 2020 (edited) 1 hour ago, tender said: Many thanks for the 'step by step' Dave. I'll have to give it another try. Ray. Keep at it Ray, its worth persevering. It may seem a bit of a long-winded process, but its well worth doing. 1 hour ago, John Tomlinson said: I've never done a full loco body, but use the technique a lot on small parts, which can allow you to get away without a primer painting coat if they just need a touch of black to finish. Blackening brass wire is especially useful prior to use in making handrails etc. Dave's insistance on cleanliness in preparation is spot on in my experience, the fluid simply won't take if there is any residual muck or grease. Worth also mentioning that "blackening" isn't quite the outcome, you don't get a deep black sheen, but rather a dullish dark grey brownish cover - as Dave's photos of the body show. Very tempted having seen this excellent outcome to try a "full monty" on my next kit! John. I blackened handrails and other small parts etc, before I tried it on a whole loco body. You're right about the colour, its great on wheels, motion etc, as the finish has the look of dull or oily steel. Additionally if there are parts in materials that don't blacken, a coat of Humbrol Metalcote Gunmetal paint is a really good match. If you are REALLY clever (which I'm not) you can control the depth of the blacking by reducing the time in the solution. Martyn Welch once showed me a highly detailed 0-Gauge boiler backhead in all sorts of varying shades, that he had done with careful blackening. Edited May 25, 2020 by DLT 4 1 Link to post Share on other sites More sharing options...
bgman Posted May 25, 2020 Share Posted May 25, 2020 Dave, Whilst looking through the garage last week I came across some of Carrs Metal Black for Nickel Silver. Prior to using this I have tended to use Gun Blue but as I had a spare Slaters O Gauge wheel the thought occurred about trying the Carrs product on them as a test piece. The steel rims were given a good clean prior to administering the N/S liquid and I was pleasantly surprised at the result, being somewhat better than the Gun Blue. I'm certainly not into alchemy but after treating and giving it an extremely light oiling then buffing up I am really pleased with the results. No ill effects to date and when tested with my meter no loss of current. G 4 Link to post Share on other sites More sharing options...
John Tomlinson Posted May 25, 2020 Share Posted May 25, 2020 6 minutes ago, bgman said: Dave, Whilst looking through the garage last week I came across some of Carrs Metal Black for Nickel Silver. Prior to using this I have tended to use Gun Blue but as I had a spare Slaters O Gauge wheel the thought occurred about trying the Carrs product on them as a test piece. The steel rims were given a good clean prior to administering the N/S liquid and I was pleasantly surprised at the result, being somewhat better than the Gun Blue. I'm certainly not into alchemy but after treating and giving it an extremely light oiling then buffing up I am really pleased with the results. No ill effects to date and when tested with my meter no loss of current. G The issue of conductivity on whel tyres is someting that has always bothered me. When Heljan started their 4mm diesel range the wheels were subject to some form of blackening which looked fine and realistic. Unfortunately it appeared to carry on reacting so that if you didn't use the loco for a while and then tried it, it wouldn't go without a lot of wheel cleaning! Interesting to read of your experience with Slaters wheels as I've been doing some modelling in 7mm. I used blackening fluid on some driving wheels as otherwise they seem prone to corrosion, having read somewhere that it shouldn't affect conductivity, and your experience is further proof. John. 2 Link to post Share on other sites More sharing options...
RMweb Premium DLT Posted May 25, 2020 Author RMweb Premium Share Posted May 25, 2020 These questions come up regularly! The blacking process changes the colour of the surface of the metal, and doesn't affect conductivity. It can leave a powdery deposit that you need to clean off. You still have to keep the wheels clean though, and after time and regular cleaning you may need to re-blacken. As for the type of blackening solution, I'm reliably told that Carrs is actually Birchwood Casey in a different bottle. Also, I've only got the Brass solution, but it works just as well on nickel-silver and steel. Cheers, Dave. PS I've edited another photo into the procedure above. 2 Link to post Share on other sites More sharing options...
John Tomlinson Posted May 25, 2020 Share Posted May 25, 2020 16 minutes ago, DLT said: These questions come up regularly! The blacking process changes the colour of the surface of the metal, and doesn't affect conductivity. It can leave a powdery deposit that you need to clean off. You still have to keep the wheels clean though, and after time and regular cleaning you may need to re-blacken. As for the type of blackening solution, I'm reliably told that Carrs is actually Birchwood Casey in a different bottle. Also, I've only got the Brass solution, but it works just as well on nickel-silver and steel. Cheers, Dave. PS I've edited another photo into the procedure above. Many thanks for your very illuminating and helpful posts. I've only ever used the Birchwood Casey products, so interesting to read your last comment! John. Link to post Share on other sites More sharing options...
mike morley Posted May 25, 2020 Share Posted May 25, 2020 If all the process does is change the colour of the surface then, presumably, it can still be soldered? Link to post Share on other sites More sharing options...
RMweb Premium Daddyman Posted May 25, 2020 RMweb Premium Share Posted May 25, 2020 4 hours ago, mike morley said: If all the process does is change the colour of the surface then, presumably, it can still be soldered? No, not at all - or at least not in my experience. I tried blackening a few years ago after reading Dave's thread, but what I didn't like about it was that it resists solder (that's why it's useful as a coating for parts that you don't want to gum up with solder - one side of valve gear components, for example). This means that if you'e making ropy 90s kits as I often am - and by the looks of it, Dave is too - and the primer reveals a problem, it's a major PITA to un-solder or re-solder anything; the blackening solution makes a horrible mess when heated. I suppose a counter argument is that it's just as hard to un-solder or de-solder things once they've been etching primed, which is true, but there was just something really nasty about the goo that resulted from heated blackening solution. I've never gone back to it. Apart from that issue, I found that it simply wasn't effective: edges treated with blackening solution were just as likely to scuff as those without - though admittedly I could have been doing something wrong. But then on the other hand, I don't know of a professional painter that recommends blackening as part of the preparation of a model for painting. Are there any? One last thing: if no blackening is happening, don't be tempted to leave things in for longer and longer - I had a cab roof end up with rivulets etched into it... 1 1 1 Link to post Share on other sites More sharing options...
RMweb Premium Popular Post DLT Posted May 28, 2020 Author RMweb Premium Popular Post Share Posted May 28, 2020 The current "state of play". Looks a bit odd without a tender, but there is still a bit more work to do on that before painting. 15 13 Link to post Share on other sites More sharing options...
RMweb Gold Tony Teague Posted May 29, 2020 RMweb Gold Share Posted May 29, 2020 Looking good! 2 1 Link to post Share on other sites More sharing options...
Guest Jack Benson Posted May 30, 2020 Share Posted May 30, 2020 On 16/04/2019 at 01:40, DLT said: Two bridging wires fitteds, linking the two pickup plates together. One is visible in this picture, also the plasticard washers under the fixing screw and nut. To hold the motor in position I've added another small frome spacer, on which is pressed a small blob of Blue-Tack that holds the motor down comfortably. Cheers, Dave. Hi, Which High Level Gearbox was used with the Mashima motor? Thank you Cheers and Stay Safe Link to post Share on other sites More sharing options...
RMweb Premium DLT Posted May 30, 2020 Author RMweb Premium Share Posted May 30, 2020 21 minutes ago, Jack Benson said: Hi, Which High Level Gearbox was used with the Mashima motor? Thank you Cheers and Stay Safe Hi Jack, I didnt built the loco, but I'm pretty sure its one of the RoadRunners. Jack.P built the kit; https://www.rmweb.co.uk/community/index.php?/topic/120327-southern-railway-modelling-southern-steam-on-shed/ My job was pickups, cylinders and valvegear. Cheers, Dave. 1 Link to post Share on other sites More sharing options...
Jack P Posted May 30, 2020 Share Posted May 30, 2020 Yep - I'm pretty sure from memory it was a Roadrunner + Dave did an absolutely amazing job (thanks again Dave!) - the loco really needs to be finished, it's been in construction for over 2 years!! 1 Link to post Share on other sites More sharing options...
RMweb Premium DLT Posted June 1, 2020 Author RMweb Premium Share Posted June 1, 2020 I've edited another photo into the Blackening message 2 1 Link to post Share on other sites More sharing options...
Wilton 34041 Posted June 5, 2020 Share Posted June 5, 2020 Hi Dave, I find this is all very interesting, your quite the expert. I've not tried blackening but I think I'll give it a try. Tell me, what do you use in the ultrasonic cleaner? Is it a regular household cleaner in water? Phil. Link to post Share on other sites More sharing options...
RMweb Premium DLT Posted June 6, 2020 Author RMweb Premium Share Posted June 6, 2020 Hi Phil, I just use warm water, I know there are various solutions on the market, but I've not tried them. I suppose it depends whether you are trying to de-grease at the same time. Cheers, Dave. Link to post Share on other sites More sharing options...
Wilton 34041 Posted June 6, 2020 Share Posted June 6, 2020 Hi Dave, Thanks, that's nice and straightforward. I guess with modern life I expected it to be more involved. I'm quite looking forward to seeing the loco finished, is it going to an exhibition layout? Phil. Link to post Share on other sites More sharing options...
gz3xzf Posted June 6, 2020 Share Posted June 6, 2020 Hi Dave, would it be possible to tell us more about the Ultrasonic Cleaner itself, I have not looked at them at all and wondered what make you have and what capacity is it? Link to post Share on other sites More sharing options...
RMweb Premium DLT Posted June 8, 2020 Author RMweb Premium Share Posted June 8, 2020 Hi Bryan, I'm not sure if it helps much, but this is the one I've got: https://www.amazon.co.uk/James-Ultrasonic-8000-High-Cleaner/dp/B000XXVWTM I'm assuming its not produced any more. I've had it a long time, and I can't remember where I bought it or what it cost! I know it was a step up from a basic home/jewelry model, but I expect they've improved in the intervening time. All the best, Dave. 1 1 Link to post Share on other sites More sharing options...
RMweb Premium Popular Post DLT Posted June 8, 2020 Author RMweb Premium Popular Post Share Posted June 8, 2020 (edited) On 06/06/2020 at 12:29, Wilton 34041 said: I'm quite looking forward to seeing the loco finished, is it going to an exhibition layout? Hi Phil, It's "home shed" will be on a very large home layout. I'm looking forward to seeing it finished, here is the current state: Edited September 6, 2022 by DLT 11 8 1 Link to post Share on other sites More sharing options...
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