W1 as rebuilt

[mickoo]

Peter,

The slide bars are laminated but not like the A3 or A4 or any other traditional set of slide bars, one of my pet hates is trying to clean the cusp off the inside where the cross head runs, so I came about the problem from a different angle, all will be revealed..... or re-revealed as I I've shown it before....shortly.

Yes the cylinder top is supposed to be clear of the main frames, like the slide bars the cylinders are a different approach to this area and the sides are joined by the top, the top has to be sloped to the same angle as the footplate as it supports the valance support plate and thus the cylinder wrapper.

 

[P A D]

Thanks Mick,
I did search back to try to find the slide bar post but got lazy and asked the question. Just had another look and got lucky and found it.

It's a very nice solution you've come up with. Having now done two sets of Martin's original design, removing the need to de-cusp between the bars is a big time saver and an improvement.

Cheers ,
Peter

 

[mickoo]

Just a small update, loco springs and under gubbins added.

Frustratingly, the more I clean it the browner the nickel silver becomes, which is becoming a bit of a chore and frankly irksome.

 

[P A D]

Frustratingly, the more I clean it the browner the nickel silver becomes, which is becoming a bit of a chore and frankly irksome.

Hi Mick,
Looks fine in the photos. However from reading your posts and speaking to you at shows, I know you set the bar very high.

What do you clean it with? As well as the mechanical cleaning (scraping, scratch brush, Garriflex block and wire brush in mini drill), I use a shiny sinks/hob bright type product depending on what I can find in the local supermarket. They clean really well but take a lot of rinsing to get rid of any residues, which tend to cling to solder and show up white. Lately I've used Viakal on both brass and nickel silver with reasonable results. However, if left on too long it can stain brass (not sure about NS) so I apply, scrub well with and old tooth brush or similar then rinse off asap. You've probably tried this as well so sorry if I'm teaching you to suck eggs.
Cheers,
Peter

 

[mickoo]

It looks fine for several reasons, expensive photographic software and careful positioning of the model to hide the worst.

I've tried them all, bar keepers friend, Cillit Bang, Lime Lite, Viakal, hot water, hot water and fairy, dilute bicarbonate soda, white vinegar, etc.

Generally speaking they have pretty much the same results, or two distinct results, the chemicals turn solder black (not a problem as you just need to keep excess solder to manageable levels) but after a while turns nickel silver brown. The soda, hot water and vinegar turn solder white and leave a residue but also white stains on the nickel silver, probably calcium from the hard water in this area.

Everything is fine whilst wet but as it dries it turns brown and the next morning it's just ugly, clean but looks a pigs dinner. Mechanical cleaning this late in the day is near impossible, there's a lot of small parts, some fragile, and lots of nooks and crannies so getting a wire brush in is impossible. Fibre brushes (pencil) aren't worth toffee, this current batch is near useless, short or long the fibres break off in seconds; soaking in dilute white glue helps......marginally; I'd happily pay £5 a refill if it lasted more than two days. The bigger burnishing brushes are much better, but being 8 mm in diameter limits there use in tight spaces.

I reckon you can get maybe three washes with a chemical cleaner before it starts to discolour the metal and once discoloured near impossible to recover. With this chassis I kept it to a minimum but it was the calcium blotches that clung to the metal from washing in hot water that forced it's use and then it's down hill from there.

I'm tempted with a ultrasonic cleaner, it'll clean the work but I doubt it'll get rid of the tarnish.

This is not something new, in fact the A7 tank engine inside the cab was so bad I've had to temporarily solder the roof on to hide it; it looks like a weeks worth of tea stains on the floor and in the corners.

There must be a chemical way to neutralise the flux and not leave either white calcium stains or chemical browning of the material.

MD

 

[Ressaldar]

Hi Mick,

I fully understand your passion for achieving the cleanest finish, but is there a case to put forward that the discolouration may/does in fact assist with the adhesion of the primer to the metal and that you are lessening this potential benefit by putting the workpiece through all of these cleaners when in fact one clean at the end of each session followed by one overall clean immediately prior to applying the primer might achieve the result that you are striving?

I have not had any failures to my knowledge, by using the 'one off' principle and will continue with this method until 'proven' otherwise.

kind regards

Mike

 

[mickoo]

Mike,

Cannot disagree with that train of thought one bit, except, the photos need to be high quality for the instructions, kinda looks shoddy sticking photos of dirty/tarnished work in your instructions, well to my mind it does. Imagine opening up your £500 plus model and flicking through the instructions to find tardy, dirty and tarnished photos, not good cricket really.

As the instructions need to be built up as the model goes along you need to keep it clean at each stage, hence the multiple washing/cleaning. The other option....which I actually did on the GNR tender....is to fully build it and then primer it in grey. This worked very well as it's much easier to photograph the grey primer model than polished metal and much more detail can be seen. The only down side is that you have to then remember the build process and how to write it up at the end, not too bad for a tender but I'm already at four weeks on this chassis alone.

The trick I suppose is to take photos of each section as you go along, dirty and tarnished or whatever (place holders in reality), annotate and write up so you have a working product, then at the end primer it and go back and take the views again, this time with the nice clean painted model, insert into the instructions and all will be well.

If it were a build for myself then yup, it'd make no odds and one good clean or one or two during the build would be fine but for publications it has to be clean.

There's a couple of other options I'm looking at, a water softener which will help with the white blotches and residue once dried after washing with just hot water and mild detergent, also good for the rest of the house so the cost is justified; second, a bead blaster cabinet, that may remove some of the staining from the chemical cleaners.

I did try for an hour or so this evening to polish it with wire brushes in the Dremmel, the brass one didn't do a lot but the steel one did, quite well until suddenly for some unknown reason it just grabbed the metal overlay and effectively fluffed it up. Initially I though it might have got too hot or too much pressure, so letting it cool down (wasn't even mildly warm to begin with) I tried again, within seconds it started to grab the metal and distort it....hmmmph....it's kinda smoothed out now but is just another area to avoid in the photos.

Overall the exterior is nice and shiny, looks nice to, but it's still bloody brown tinted. Whatever chemical reaction has gone on is very deep in the metal, even really hard fibre brushes fail to lift it out. The end result is either more aggressive chemicals to try and restore the colour or simply less of them to begin with in the first place.

Ironically I've only got a handful of brackets and cylinder wrappers to fit and the chassis could go for primer almost right away.

MD

 

[warren haywood]

Regarding primers on sparkly clean brass, there should be no problem. That is unless you use Halfords primer, which basically isn’t fit for our use except maybe with plastics.
I mix my own primer but it’s basically the same as precission two part primer. If applied to a clean surface you will not shift it after 24hrs. The precission product is fantastic if used with enamel paint but no good for cellulose. If using cellulose paint you need to substitute the paint part of the primer for one with a cellulose base.
Don’t forget that the primer is the most important coat and should just be misted on to provide a key. I see so many models primed so thick and gritty (usually Halfords) that there is not a hope in hell of getting a decent paint finish.
The moral is if you have to rub down your primer then it’s way too thick.

 

[victorianman]

Re Warren's comment on primers, most car rattle cans seem now to be acrylic rather than cellulose. What would be the primer recommendation for those--it's those pesky footplate edges which always lose paint first.
Thanks.

 

[simond]

Mick,

I can readily confirm that the ultrasonic cleaner will do nothing at all for the tarnish that you’re frustrated with.

Despite imprecations from Warren and others, I used Powerflo flux as my go-to for years, and simply scrubbed with Viakal or Shiny Sinks at the end of every modelling session (and sometimes if it got too sticky, in the middle too) followed by a thorough rinsing and ten minutes in the ultrasonic bath.

This seems to get the flux & crud off (and unsolder anything that wasn’t soldered properly) but the solder goes black.

Even with this kind of regime, n/s never stays silvery, and brass goes dull, though I’ve only once had the dreaded green flux monster bursting out. I now habitually use citric flux unless for some reason, it doesn’t wet properly first time, when the little yellow pot comes out again...

So, irrespective of which, I went searching for “chemical polishing”, and “electropolishing” and found this

Magic Acid for brass???? [Archive] - The Home Shop Machinist & Machinist's Workshop Magazine's BBS

The best advice seems to be to use a fairly strong ammonia solution. I particulary liked the comment that “hydrochloric acid makes brass transparent”

I will get some ammonia and try “the clockmakers’ solution”. If nothing else, you can be sure that it will neutralise any remaining acid flux. The “Marigolds” seems like good advice too.

Hoping this helps (or at least leads to further advice)
Season’s Greetings
Simon

 

[Ressaldar]

The “Marigolds” seems like good advice too. Simon

were they on your list to Santa? Tree pressie from SWMBO perhaps?

Seasons greetings to you to Simon

regards

Mike

 

[michael080]

There's a couple of other options I'm looking at, a water softener which will help with the white blotches and residue once dried after washing with just hot water and mild detergent, also good for the rest of the house so the cost is justified; second, a bead blaster cabinet, that may remove some of the staining from the chemical cleaners.

Mick,
Neutralizing acids is not as easy as it appears, because you need to find the right amount of neutralizer. Otherwise, you will just stop one chemical reaction and start another one.
I think the idea of "soft water" may be the way to go, because it doesn't try to neutralize the PH-value on the surfrace, it simply dilutes the chemically active agent. I am using distilled water which is actually only demineralized water as a last flushing agent. After that, I blow the water off with clean shop air. I think this helps stopping any water based reaction quite effectively.

Bead blasting may actually worsen the problem, because it doesn't remove dirt from the surface, it just hardens the surface through deformation at the impact of the beads.

I am no chemist, so all above may be complete nonsense ...

Season's Greetings,
Michael

 

[mickoo]

Cheers guys

I wonder if a bowl of hot water with some fairy in or other soap medium is the better way to go, perhaps add some sodium bicarbonate to reduce the hardness of said mixture.

Force drying afterward certainly most helps, it does seem to be concentrates left over from the drying process, certainly the water cleaning method, the chemical method tends to be in corners and the such like.

It's pretty conclusive now that once browned it's a lost cause, it's very difficult to recover the cleanliness back.

Warren, I'll drift this (chassis only) with Halfords grey primer for the photos, just a light coat, then dunk it in strippers for you to put the main coats on later.

Halford primers will never compete with Warrens industrial two pack paint job, but I've had reasonably good results with Halfords grey primer and that other popular black one on underframes and the such, where uber smoothness isn't so much of a requirement.

I find preheating the model first in an oven at 40-50° helps the paint bond to it as well as preheating the rattle can in the airing cupboard or on a hot radiator.

Simon, I use safety flux for several years and that virtually reduces the green fungus monster to zero. I didn't wash my GEVO cab build after the last session and when I looked at it a few months later it did have some green spots on, so even safety flux isn't 100% fungus free, but if washed pretty quickly after application (day or two) seems to work reliably well.

MD

 

[Paul Cambridge]

I believe that Fairy liquid and such contain lanolin (please contradict if you know better) so a through rinse after cleaning is essential to avoid deposits on the brass / nickel silver. Also 16mm live steam manufacturer Roundhouse advise against using de-ionised / purified / distilled water in boilers as the residual additives from the manufacturing process can cause de-zincification of the brass. Yes I know this is for water converted to steam under pressure, not electrically driven brass models. The advice is to use filtered rain or de-humidifier water. It’s free, which is a bonus and certainly in the west of UK is abundantly available. I keep my boiler water in an opaque 5l container to prevent any green algae growing!

 

[simond]

Paul,

I’d concur that if it keeps your hands as soft as a baby’s bum, it’s probably got something like lanolin in it, and that’s likely to stay on the model after rinsing.

What I’m very puzzled by is the comment about using deionised or distilled water in a boiler - by definition, these should not have anything soluble (nor indeed, insoluble) in them, so I don’t understand how this could be detrimental to the brass (all the boilers I’ve been involved with were silver soldered copper, with bronze bushes, though brass fittings, probably) - indeed dehumidifier water is distilled! (So is rainwater, effectively, though I guess it might have dissolved something as it descended!)

Season’s Greetings
Simon

 

[mickoo]

Fairy does have lanolin and I've not had any detrimental issues (that I'm aware of) with it per se, my main problem with a soap wash seems to be coming from the rinsing afterward in hard water. The water tends to migrate to corners and puddle and no matter how quick you dry it it tends to leave a white milky stain, even on flat surfaces dried with a cloth it stains moments later.

I do have a de-humidifier and empty gallons of water a day from it (the curse of modern double glazing abodes it appears) I'll decant some of that and boil it up to rinse the model in next time and see what happens.

At the moment it's had a pretty good bullying with the polishing brush, the exterior is more presentable but the hard to reach nooks and crannies inside will sadly have to remain tarnished as it's near impossible to get any form of mechanical cleaning facility in there.

The problems only seem to become prevalent once the item has dried or the atmosphere gets to it, I've almost been tempted to leave it when not working on it submersed in water

MD

 

[simond]

Well, it won’t dissolve...

Joking aside, I note that the clockmaker advice was to rinse in v hot/boiling water, so that it dried as fast as possible.

I’ve always used hot water, but hot to touch, not hot to cook...

Might be worth a try.
Best
Simon

 

[Max M]

The water tends to migrate to corners and puddle and no matter how quick you dry it it tends to leave a white milky stain, even on flat surfaces dried with a cloth it stains moments later.

Would adding a few drops of dishwasher rinse aid allow the water to disperse more easily?

 

[Scale7JB]

I usually wrap it in kitchen towel and shake vigorously.. Just don't let go!

JB.

 

[Scale7JB]

I've also taken to cleaning with Barkeepers friend, but importantly with a 1 inch paint brush. Reaches the parts...

JB.