7mm Mickoo's Workbench - MOK Armstrong - MOK 64xx A&E

Discussion in 'Area 51' started by mickoo, 8 September 2018.

  1. mickoo

    mickoo Western Thunderer

    No in reality it doesn't matter, but personally I dislike my clients seeing models that look like :shit: :D
    Last edited: 9 June 2019
    Rob Pulham, P A D and BR Tony like this.
  2. mickoo

    mickoo Western Thunderer

    I've found that cleaning with a lime scale remover works very well, it's the subsequent wash in water and then the drying that brings on the tarnish.

    The trick is to use only nickel silver as that rarely tarnished or with brass, never touch with your fingers, even then, the more washes it goes through the more tarnished it becomes.
    Brian McKenzie, P A D and BR Tony like this.
  3. P A D

    P A D Western Thunderer

    Hi Mick ,
    I don't have clients but still dislike my models looking like :shit:s. I'm sure you're the same clients or not.

    Through errors rather than intention, I have found that if you allow lime scale remover to dry, it stains brass almost black. Started the cleaning then had to deal with a business call and left a model in Viakal for about 20 mins. It was covered in mottled stained s like camouflage! Scrubbed it off with shiny sinks/hob brite, but then that is a sod to rinse away completely. The point is re the lime scale remover, I am wondering if on rinsing, is it very dilute Viakal or whatever, that on drying then causes the rapid tarnishing???? So the more you rinse, the better chance you have at reducing the onset of tarnishing. Trouble is, there's only so much water in the reservoir and people have to drink. I wonder if a final dunk is water with a little dish washer rinse aid would help. I've tried using a final rinse in washing up liquid but that didn't help and I think rinse aid is just a surfactant of some sort so maybe that's a dead end also but I'll give it a try.

    Superb build by the way.

    BR Tony and Rob Pulham like this.
  4. Focalplane

    Focalplane Western Thunderer

    I have started using stainless steel sink cleaner (GIF INOX in France) and so far so good. Water stains remain a problem though.

    In the metal finishing industry chemical polishing has been around for decades. It is often referred to as reverse electroplating where the item to be cleaned is the anode, not the cathode. The liquid medium is usually a nasty acid based combination. Not something to leave lying around in the kitchen.
    BR Tony likes this.
  5. mickoo

    mickoo Western Thunderer

    I should clarify, before anyone gets too much hold of the shitty end of the stick, I've nothing against those that do not clean their models nor am I leading some sort of crusade for micro clean models :D

    To date all my model builds have either been for clients or Finney7 instruction builds, both of these requires models with a generally clean appearance, specifically the instruction ones. I and all of the F7 crew also believe that showing a model being built is proof that at least one has been made before the parts were put in the box ;)

    All of us, and a great many here, have experienced kits where the part fit is so poor that they could never have been test built :eek:.

    If you're doing commercial work and building a client base, then I think good clean models is important to show case your work. Good clear and large photos show progress and leave little room to hide and thus the drive to get it right is much higher.

    I'd also stress that there are two types of cleaning, all of the above is simply washing the model and trying to maintain a clean brass surface, nickel silver does not suffer from this at all, wash with cleaner, rinse in warm water and dry, all tickity boo. It will eventually degrade and become dirty but it takes months, near years compared to brass which takes weeks.

    The other cleaning is the mechanical cleaning, aka solder, this I do much less of compared to models of, say last year. Don't get me wrong, there are areas which have been flood soldered and are rough as hell, but all are inside and hidden once assembled, even when turned upside down.

    The latter requires a different approach to building, less solder requires less cleaning and on the Princess Coronation I'd say 95% was assembled with a blow torch, much faster and much cleaner. There are still areas where something smaller and hotter is needed, basically small overlays and fine details, so small that using a torch will probably loosen something else close by or a soldering iron would leave too much residue. A resistance soldering unit would probably suffice and I think one of those will have to be on the shopping list very shortly.

    For the chemical cleaning I've tried Viakal, Bar Keepers Friend (BKF) and Cillit Bang but have recently been using Lime Lite, it's much less aggressive and prolonged usage doesn't appear to tarnish the work like Viakal, BKF or CB. It also does not turn white metal or solder dark grey or leech out the zinc and turn brass orange, though I expect it would if left too long or was immersed in the stuff.
    BR Tony, BrushType4, Dog Star and 6 others like this.
  6. P A D

    P A D Western Thunderer

    On brass vs nickel silver re tarnishing, it was the latter's resistance to it that meant it was the metal of preference for top end drawing instruments, from the mid 19th to mid 20th century. However it was more expensive, but with chrome plating becoming common and fashionable, the manufacturers were able to switch back to the cheaper alloy, plate it and reduce cost.
    BR Tony likes this.
  7. warren haywood

    warren haywood Western Thunderer

    Tarnished brass does not make the slightest difference when it comes to painting. Saying that I always rinse em with viakal and then celly thinners before I put the primer on.
    As long as a decent etch primer is used there will be no paint loss.

    The biggest problem is the reaction from flux or oxidation (I suppose this is severe tarnishing, sure Steph will correct me if I’m wrong) of the metal which can reveal itself as a gritty residue which is difficult to remove. It shows up through the paint generally in crevices and along uncleaned soldered edges.
    BR Tony, mickoo, Rob Pulham and 5 others like this.
  8. mickoo

    mickoo Western Thunderer

    Inside motion, is it worth it, I think so.




    Amazingly it all works, mind it is tight due to the reduced frame widths for O fine, especially when the inside cylinder bores are to scale.

    The webs on the cranks are so long that there is little lateral room for play on the inside connecting rod when the crank is aft of dead centre, thus the cranks have to align pretty well spot on with the cylinder bores, which brings them very close to the axle boxes.

    The leading springs have to go back on, they might as well as once the inside connecting rods are pinned to the crossheads nothing is coming back out without serious surgery.
    Ian_C, LarryG, Deano747 and 17 others like this.
  9. simond

    simond Western Thunderer

    And therein lies a question. If building a layout loco, presumably one gets to this point, checks everything swings & wobbles as it should, or fettles, fiddles & files to get to that point, then strips it to paint.

    Having built a dozen or so (mainly GW) locos, I’ve never fitted inside motion, nor “working” inside valve gear.

    What’s the view on how to strip & rebuild it, and perhaps avoid too much surgery?
    Richard Coleman and BR Tony like this.
  10. Isambarduk

    Isambarduk Active Member

    "What’s the view on how to strip & rebuild it, and perhaps avoid too much surgery?"

    I arrange for all the parts/sub-assemblies to be screwed or pinned. After painting and reassembly, I secure the screws and pins with varnish (so that they may be removed, if necessary).

    Deano747, Focalplane, BR Tony and 4 others like this.
  11. mickoo

    mickoo Western Thunderer

    Nearly there, weighted, motored, wired and pick up running chassis.

    Not quite enough weight but all the spare (blind) places on the chassis are now used, this only leaves the boiler which has to be kept clear (for the time being) to fit the speaker, once that's in a weight will have to be inserted from behind to bring the engine up to a useful weight.



    Wipers are simple wire on rim affair as detailed on PADs tank engine, though I've used 0.7 mm NS as it's all I've got to test and set up, so far it works well enough so I may well not change to phosphor bronze. I joined the two paxolin strips with a solid wire bus, this stops the strips twisting when the screws are done up or during use and thus the wipers dropping off the rims.

    I made a couple of wire hooks each side of the motor and it's just held in place with two small rubber bands, simple is as simple does.

    That's basically all the hard parts done, the rest is bish bash bosh, monkey see monkey do work; so hopefully all done by next weekend whence it'll be off up to the painter ready for him to do his magjik :thumbs:
    Ian_C, Scanlon, Rob Pulham and 10 others like this.
  12. Focalplane

    Focalplane Western Thunderer

    So Walschaerts valve gear is bish bash bosh? I tremble at the task ahead!
    BR Tony likes this.
  13. mickoo

    mickoo Western Thunderer

    Yup, I think so.

    Remember you're only ever dealing with two parts at any one time and before you know it, it'll all be done :thumbs:
    Isambarduk, BR Tony and Focalplane like this.
  14. P A D

    P A D Western Thunderer

    I agree with Mick, especially when it's a Finney 7 kit. From what you've shown of your work so far it should be no problem for you.

    Nice idea joining the copper clad wiper mounts with solid wire, to reduce the risk of them moving when tightening. On the additional weight in the boiler to be added after the speaker, what about trying the tubular finger bandage with lead shot? Easy to do, no glue needed and easy to remove if you need to get the speaker out.
  15. mickoo

    mickoo Western Thunderer

    Peter, that's exactly what I'll do, thank's for the tip.
    BR Tony likes this.
  16. simond

    simond Western Thunderer

    Yes, I rather like that idea too. I shall try it, possibly today.

    Although it was Father’s Day a couple of years ago when I knocked my King off the shelf, so perhaps I’ll leave it til tomorrow...

  17. mickoo

    mickoo Western Thunderer

    As I said, bish bash bosh, one side done, there's a few pins to clean up and some are not permanently fixed as it all has to come off for paint, which is also why the inside valve rocking lever is not fitted at the moment.

    It takes longer to clean all the cusps off than to assemble in all honesty and overall it all goes together rather easily.

  18. P A D

    P A D Western Thunderer

    Looks great Mick.

    Not quite as shiny as it was as Doncaster but that's Brass for you. You may have mentioned this already, but why did you not go with nickel silver when you re launched the range? Was it cost only or was there other technical considerations?

    I put the Stanier tank in the box after the last clean and have a peek every day to see how it holding up away from the toxic atmosphere of the workbench. So far its holding up but that wont last.

    Deano747 and BR Tony like this.
  19. Dikitriki

    Dikitriki Flying Squad

    If I may answer this.

    There are 2 principal reasons. The first is cost, the second (relevant in particular for GW locos) is that N/S does not represent brass beading very well. There is a third and less significant reason in that it can be more difficult to form boilers etc. in N/S than in an equivalent thickness of brass, particularly if you don't have access to rolling bars.

    Having said that, we will make all our re-issued kits available in N/S to special order at a premium of 10%. The W1, B1 and 94xx are/will be in N/S anyway.

  20. Focalplane

    Focalplane Western Thunderer

    Thanks, Richard, you just answered my email regarding the Hall. Would you consider rolling the N/S Hall boiler for a ham-fisted customer?