Rewanui - a 1940 West Coast NZ layout in 1:64

[Lawrence@NZFinescale]

A tip From one of the greatest Loco painters - defiantly NOT ME but a friend going way back - and one of the best professional painters of our times - For metallic finishes first spray a matt grey bass coat - then lightly dry brush the metallic paint over the casting you end up with an amazing finish for  brass or steel he always used an Enamel paint for the dry brushing Humbrol polished steel or brass being one of the best products to use - if the dry brushing process is done correctly by that I mean a DRY BRUSH no pigment will show - some people have better results using a short flat stumpy brush others use a longer haired flat brush Give it a go it does work
Barney   

As it happened the old Moet tin in the bottom drawer, that holds my aged Humbrol collection, did yield a tin of met brass in good condition.  And yes, it did work quite well.  My reservations in this case are painting the matt grey and dry-brushing around the detail will be tricky.  But, honestly, anything is tricky so I may yet return to it.

[Barney]

Think of it another way the figure painters /military modellers have got it to a T - one of them told me "think brass buttons " most  use the dry brush method some used Gold pigment crushed finer then the base coat / colour is touched up around the dry brushing gold / brass the dry brush is often 2mm /3mm wide the figure people  really are just on another planet
Barney 

[Bill Gill]

Another possibility for a brass-like color without metal flakes might be to first apply an Alclad finish and then apply a transparent, non granular yellow wash over it. I've seen simulated "gold" finishes done with a transparent yellow over a chrome finish that looked gold.

I have no experience with Alclad, but its variety of shades and colors could have a suitable base that would look like brass. ALC-108 looks like a possibility.
https://alclad2.com/finishes/regular/

PY150 (Nickel Azo Yellow) is a transparent yellow that's very lightfast. It could create a belieavble brass look on top of some silver-ish base.
https://www.parkablogs.com/picture/yellows-made-py150-py151-py153-py154-and-py159#:~:text=PY150%20goes%20by%20many%20names,option%20as%20a%20primary%20yellow.

 I've read that acrylic paint adheres well on top of Aclad finish.

[Peter_T1958]

Hmm, first I did not recognised those ,,flakes"; I was simply impressed by the quality oft he print. Second we have to be aware of the dimensions!
But now that we're already talking about brass-like colors I am very interested how to do that in a convincing way as I have to paint brass acetylene lamps on my Büssing too.

So I found this video:

https://www.youtube.com/watch?v=_LkRYmTB08U

Ok, looks promising!? But let us be honest, this shaving brush methode works (well!) on a solid and strong figure but not on a tiny print with even smaller pipes and wheels. 

And... I also haven't tried it out myself!!!

[Lawrence@NZFinescale]

I'll get back to painting backheads shortly, but in the meanwhile the flameplate (or the valve chest) often had oil cans placed on them, to warm the oil for reduced viscosity.

A bit of searching and asking revealed that the "coffeepot" (as it was known by the crews) or "oil kettle" (as it's referred to on NZR drawing x12492) held steam oil which is inconveniently viscous when cool. There was a different can for bearing oil, which was less thick.

They are really small in 1:64, but formed really well. Manufactured in tin, it will provide some colour contrast on my flameplate.

[Lawrence@NZFinescale]

Here's my version 2 on the We firebox.

The print's been improved a bit and all the handwheels and details are correctly formed.  The straight air brake has been removed (as it was not fitted until 1948), and the brake handle has been placed in a running position. I've added the coffee pot to the flameplate just for fun.  I found some reference photos so I feel the colouring is more representative.

Presented here on a Humbrol tin to illustrate the actual size.  I'd suggest evaluating the overall result at modest magnification.  It certainly breaks up a bit at extreme magnification, but that's not really the point for me here.

Brass work this time is Rub n Buff (Grecian gold), let down with a bit of dirty brown enamel wash to make it brushable.  I gleaned this suggestion from Chuck Doan.  I'm more pleased with the colour and the flake is not noticable until you really blow things up.  I'm not sure exactly what went wrong this time, but my primer didn't really harden off properly, and the model suffered in handling and my attempts to buff the brass.  If I can get a harder base the Rub n Buff will burnish up a bit better.

The resin is also a bit soft.  Next time I'll rig up something to hold the model to reduce handling and exercise a bit more patience.

I still see this one as a learning piece, so I haven't spent as much time as I might on final tidying.  If I persist with the Rub n Buff, I'll need to make sure I can remove the extraneous gold dust.

[finescalerr]

So that is a second "pilot model" of the backhead? If so, your third attempt will be a home run. Most satisfactory. -- Russ

[Lawrence@NZFinescale]

So that is a second "pilot model" of the backhead? If so, your third attempt will be a home run. Most satisfactory. -- Russ

Err, yes.

The work involved in producing the digital file is quite large (although individual parts are mostly standard and recycled)
One of the good things about posting pics is you get useful feedback on both the modelling and the prototypical accuracy. In fact, one of the members here has a reputation for producing the workshop drawings after the model has been published.  Thus I've been trained to exhibit work in progress early so I can benefit from information arriving before the final model is complete.
The work in optimising the file and it's printing is not that arduous, but consumes time to actually run prints.
The net result of all that is a ready supply of prints or at least the means.
Actually painting them is not all that time consuming, and is the fun bit in any case.
So whether they end up here or not, there will likely be another one or two. I still need to give Bill's brass method a go for starters. Given that the etching artwork for the loco is still incomplete the cab interior is rather more advanced than is sensible :-)

[Barney]

Well things are looking better with the brass finish - most painters will always say its one of the most difficult things to achieve - but saying all that I think the forum has come up with some great thoughts on achieving this issue and I'm sure their will be many more to come - perhaps we should open a new file under painting instead of invading your space on this fantastic model subject
Your workmanship involving 3D printing is just amazing - way beyond me ever understanding this form of magic and especially in such a small scale - I recently had some 3D printing done by a company and it was for a large scale 1/16th - it was for some coupling pockets (I think that's what you call them  ) see my Union gas engine critter thy were a total  mess it took me ages to clean them up !!

Just a thought would it have been better to have done the back head first making the painting of the large brass bit easer to paint and then added the controls or is this not the way to do it - as I say I know nothing about this form of "Magic" and I most appreciate your fantastic Amazing way of creating such delightful models
Shot below of one I had in the oven earlier - Thats a joke Russ !!!!
Barney
signed up agin for my flower arranging class again !

[Lawrence@NZFinescale]

A few thoughts on Barney's comments:

In the austere 1940's, on very minor lines, I doubt the brass finish was kept as pristine as today's preserved lines, so mirror finish is not my aim.  Having said that achieving a good finish and then weathering it would be my preferred route.
3d printing parts at this small size is all about support.  Generally, designing assemblies with painting in mind is a good idea but here having a single part removes many nightmares, and is the only approach I can see working.  Painting is not as bad as you might think as there is clearance between parts in most cases so it's possible to get a brush around and behind. The main issue with the brass clothing is that any technique requiring buffing, large brushes etc is a bit impractical.

The bottom line with this particular sub-project is that I could easily live with either version so far presented on the grounds that it's a mostly hidden item that will not be available for close inspection.  On the other hand I'm interested in improving my skills so that such items will stand alone and they are fun little things to play with. Once developed I can turn them out 6-10 at a time, so it is not a major investment to dabble with a few.  That's quite a contrast to the issues I faced when assembling such things from castings, etchings and bits of wire.

[Bill Gill]

Lawrence,
The second test backhead is looking even better and the 'coffeepot'on the flame plate is a neat touch.

If you go with the gold Rub n Buff for the brass, could you apply a thin layer with a tiny makeup sponge instead of a brush and then buff it with a tiny piece of chamois on the end of a stick?

Rub n Buff is metallic pigment in carnuba wax, so any stray spots of gold that don't simply wipe off can be carefully removed with a toothpick dipped in alcohol if you don't disolve any acrylic paint.

[Lawrence@NZFinescale]

Thanks Bill

Diluting the Rub n Buff made it quite brushable - which worked well.  I didn't have chamois, but used a bit cut from an old cycling glove - synthetic 'chamois'.  The days when I had real chamois around are long gone, but I'll look out some fine leather. I suppose I could go into the hills and shoot one.  I'll try sticking it to a bit of balsa as that should leave the paint alone.

[Hauk]

A bit of searching and asking revealed that the "coffeepot" (as it was known by the crews) or "oil kettle" (as it's referred to on NZR drawing x12492) held steam oil which is inconveniently viscous when cool. There was a different can for bearing oil, which was less thick.

They are really small in 1:64, but formed really well. Manufactured in tin, it will provide some colour contrast on my flameplate.

Lovely little piece of detail. What is the the diameter of that handle?

[Barney]

Thanks for the info on 3D printing I now have a better understanding about the support that is required  and how to produce it
You are doing a great job of a small model with the prototype at the top of the list
Thanks again
 Barney

[Lawrence@NZFinescale]

Lovely little piece of detail. What is the the diameter of that handle?

It's a funny shape.  Should be a 'D' section on the grasping side, but otherwise sheet - which obviously wouldn't resolve.  So it's scale width and a shape I hoped would look as narrow as possible, but be meaty enough to actually resolve.  No real science, and fortunately it worked first time. Handle section shown in the image.

During printing these fine wires are prone to wander around a bit due to their flexibility and thus the actual printed dimensions are likely a bit different