Burnishing, blacken-it, anodising, electroplating...

[Sam Hough]

More out of curiosity than anything concrete has anyone tried products like:
http://ak-interactive.com/v2/?product_c ... ng-liquids
http://www.swannysmodels.com/Blackenit.html
https://www.birchwoodcasey.com/Refinish ... ch-Up.aspx
?

I'm trying to get a chemist at work to explain how I could do electro plating but I'm still stuck trying to understand the difference between plating and anodising.

I've read the knowledge base links but not seen anything about these products. I didn't know rust was such a hot topic http://www.armortek.co.uk/Forum3b/viewt ... f=2&t=5409

Many thanks

Sam

[Fabrice Le Roux]

Hi Sam,

FWIW I have tinkered with some of the Metalblak compounds, but along with my friends in the model train department, I have found the the coatings to be fragile, and too thin to stand up to rough handling/use. Fine for varnished static parts, only. Chemical blacking and electroplating creates a layer only a few microns thick, and any flaw in the underlying material will compromise the integrity of the finish, leading to pitting or adhesion failure. Hence for chromed finishes, an intermediate substrate (such as nickle alloy) is applied.

This is further amplified by the complex galvanic corrosion processes that arise in models of dissimilar metals.

For Armortek models, the proven route is to build the model, disassemble, degrease and lightly prime all components with an acid etch primer then reassemble before the final paint finish is applied.

Where you have aluminium and steel in contact a layer of primer is essential as galvanic corrosion takes place even at room temperature and moderate humidity. If you are building a bare metal finished model (and why not, they look great) then a fine layer of clear laquer between dissimilar components, will serve the same purpose.

I have used Halfords Upol #8 Grey primer for several years and it is very good. So stable that I have items primed 10 years ago that are still in pristine condition. It is also heat resistant, so local soft-soldering can be done, without the rest of the piece needing to be reprimed. The grey colour works very well with sand coloured vehicles, but I have recently started using wholesale Black acid etch primer on Olive Drab vehicles (based on similar use of Warhammer Chaos Black paint for 1/35th plastic tank kits). The black primer adds a volumetic density to the vehicle and serves to make the recesses deeper and darker. As a recipe, I would consider using black primer from the trackguards down and grey for the upper superstucture.

Anodisiing aluminium is feasible but the colours and surface specularity do not match any military vehicle in our time period, likewise powder-coating is too thick to maintain dimensional accuracy when reassembling.

For an in-depth analysis of the the issues surrounding creating stable, lasting paint finishes for model engineering projects may I recommend the book ,"How (not) to paint a Locomotive" by Chris Vine.

His secret sauce is wherever possible to grit-blast/roughen components to achieve a mechanical key to work in tandem with the chemical key of an etch primer.

Everyone has their own MO, so this is just my ha'penny worth.

cheers
Fabrice

[Stephen White]

Sam, fair question. Fabrice, as ever, has nailed the science and best model engineering practice.

You've obviously done your homework and in the process probably answered your own question. There isn't any mention of these products in the Knowledge Base because no-one has yet come up with an appropriate use for them on an Armortek model. Is your question directed at tracks specifically or more general?

The colour of Armortek tracks as delivered is a pretty good starting point for operational tracks (see the photo of Centurion tracks in the thread you quoted).

There is benefit in giving the links, pins etc some protection, which is why the majority of builders go through the steps of etch priming and painting, as Fabrice says. There are a couple of weathering products which do have a use, pigments (and fixer) and synthetic mud but in most cases there are cheaper alternatives which are just as effective (such as pastels and oils). There are some examples of how to do it on the Forum.

You'll find Ian Collins chose to have his Centurin powder coated but I can't recall anyone using any chemical coating processes (except maybe for a silver Tiger a while back).

All the best.

Stephen

[Sam Hough]

Many, many thanks for the very detailed and helpful responses.

I am thinking about tracks, the only bit my Dad is letting me do.

I think the new tracks are a darker and duller finish than our 2003 issued model. Also, for better or worse, I've removed some casting marks so I've made new bright spots.

This is the picture I'm using for reference:

To me the underlying colour looks like a very dull dark grey. Is that just the picture or because it is a museum tank?

I think I might play with anodising with lead on a test piece just out of curiosity (if my chemist friend can tell me how to get rid of the resulting mess).

If I have fingers and eyes after all that I'll probably be sensible and do the harsh cleaning, etch primer.. it hadn't crossed my mind at all about the corrosion due to different metals.

I need to re-read all the knowledge base links. So my wife can give me a patronising look and say "more tanks".

Many thanks again.

Sam

[Graham Hough]

Thank you Fabrice
Following your advice I will prime the steel brackets before I bolt them to the aluminium chassis and also prime the steel deck before bolting to the steel brackets and because it will press against the aluminium chassis too.
Also you have answered my question about the Halfords primer.
Thanks again, Graham

[Armortek]

We have been contacted by a 'follower' of the forum who wanted to pass some information on relating to this thread. We believed this would be useful and I have copied below.

Electroplating is a technique whereby electricity is used to coat a metal with another metal eg. copper plating on steel.
Anodising uses electricity to build up an oxide layer on, generally, aluminium although it can be used on a few other metals. This coating is initially porous and is sealed by immersion in boiling water. Before sealing, the object can be immersed in dyes and then sealed. This gives a coloured layer which is very hard wearing. The two techniques are, therefore, applicable to different substrates.

Thanks to Nigel Deacon for this information.

[Sam Hough]

Thanks Armortek and Nigel,

This method http://hackaday.com/2011/10/17/anodizin ... tery-acid/ looks a little less scary.

No idea what dyes can be used. Seems within my ability to experiment and then cover it all up with paint.

Cheers

Sam

[Fabrice Le Roux]

Way to go Sam!
If you don't like the result, just paint over it.
Fortunately even naff, inappropriate coloured anodised finishes can be easily grit-blasted and painted into oblivion.
Heuristic bias, thou art a heartless bitch! Sorry Mr Deacon..

Fabrice

[Fabrice Le Roux]

Hi Sam,

On a more serious note, the photo you show is ,I think, the Tank Museum's Tiger 131.
Well done to you for sourcing a "real" photo rather than defining your colours on OBE's, other chaps' models, so to speak.

La belle 131, when not sitting in the TM workshops, being pampered like the prize pussycat she is, sits parked on a sand filled tray in the WWII display section. When driven round the display arena she traverses ground that is predominately chalky and sandy. The arena outer roadway is, I believe, an igneous/basaltic ballast (granite chippings to us mortals).

Hence the colours you see in the reference photo only reflect the immediate and modern usage of the vehicle. Weathering, not just of the tracks, is a narrative. This changes over time.

So it may be worth looking at any colour photos of other Tigers, in other Museums. My personal observations are that surviving German AFVs' Tracks seem to have a redder patina, whereas contemporary Allied vehicles, especially British vehicles, seem to have a darker black/brown patina to their tracks. I am given to understand this is due to the higher magnesium content in British castings. But I am always open to expert opinion on this.

A total delight of Armortek models is that the wear on the tracks, both of the treads and the internal surfaces, once the model has been run for even a few tens of minutes, knocks most static model-makers efforts into a cocked hat in terms of realism. Gleaming, worn, bare metal..just perfect!

Bottom line. If it looks like tracks are "right" on the vehicle then the weathering balance is probably right. If you put figures and kit on the vehicle make sure you weather them as well. Nothing spoils a model more than pristine uniforms, jerrycans and bulled-up gasmask containers that look like they have been teleported in from the Nuremburg Rally!

Best of luck with you and your Dad's model!
kind regards
Fabrice

[Sam Hough]

Thanks Fabrice!

I am looking forward to the wear on the tracks making them look really interesting. I'm just trying to give it a good start.

It is only just sinking in that another big advantage of 1/6th is that you can have a few goes at things. I was really impressed with somebody taking a hand drill to their tank to add some "character". Not sure out 1/16th tamiya would take sand blasting or power drills.

Any idea what they did with spare track links at the front?

Are those any indication of the colour under the muck? From photos via cheap laptops they look very close to the way they come from Armortek in the last few years.

What I really need is a high end CNC machine to do the fiddly bits on the edges of the tracks. Need to be nice to the right person at work.

Thanks

Sam

[Sam Hough]

At the risk of using/abusing this forum to keep my references:
1) http://www.network54.com/Forum/409173/t ... ack+colour

2) http://www.warrelics.eu/forum/germany-w ... ink-85904/

3) https://vincesgallery.smugmug.com/Histo ... -3XdRH7g/A


Suggests to me that they are quite dark with a hint of red (as Fabrice said).