realistic appearance of tracks

[Steven Ford]

In the distant past there has been discussion of the best way to give tracks a realistic finish. Eventually I used two shades from Precision Paints - rusty rail track and dirty rail track - applied in a rather coarse and random fashion. My line of thinking was that rail and tank track are both ferrous and naturally rusty and dirty.

My knowledge of metallurgy is too poor to be sure but I gather that some steel structures (Angle of the North for example) are made of a type of steel that is specifically intended to remain uncoated and rust at a pre-determined rate. Would it be a good idea to make the links on our kits from this naturally rusting but long lived steel and have the pins made of something else - stainless or titanium or something?

[Armortek]

Hi Steven

The track links on our tanks are made by a process called pressure die casting. This technique allows us to produce crisp, accurate detail and to achieve good flaw free material. They are cast in an aluminium alloy. Unfortunately you can not pressure die cast steel. In steel you can sand cast, which is cheap but inaccurate and prone to flaws, you can investment cast, which is good but very, very expensive or you can precision sand cast, which is also very expensive. Add to that the weight of cast steel links and you have the reasons that we choose not to go down that route.

In all types of casting there is always a trade off between die cost and part cost. The more you invest in the die, the lower the part cost and vice versa. For info the average cost of a die for a 1/6th scale track link is £10k. Once made they are very difficult to modify.

Mark

[Steven Ford]

Thanks for this reply.

Probably safer if I stick to my day-job - if I had one...

Today is the first day that my Tiger has had it's tracks on, that's what sparked the line of thinking.

One day I'll make a serious effort to get down to Devon on the open day and see how you perform all the other miracles.

S

[leesellars]

Hello Steven

You also can go down the route of painting them. Chris Fry has done a fantastic job of doing his King Tiger tracks. See my Gallery page 10.

Lee

[Steven Ford]

That's better than my effort - Thanks for the pointer Lee.

[Fabrice Le Roux]

Steven,

Once you have driven the models around for half an hour nature does a lot of polishing and weathering free of charge.

FWIW I have a Tiger 1 with tracks that were grit blasted then spray-painted with Halfords Red Oxide, allowed to dry for two weeks, and given a wash of Matt Black Pelican Paint very thinned with white spirit, worked into all the recesses. Tread side first, leave to dry for a couple of hours, flip the track over and do the toothed side. Scrub over any obvious blobs near the edges, imperfections in the middle of inner part will never be seen before they wear away.

On the Sherman, the track pads were grit blasted and hand painted in Phoenix Black self etch primer. Dirt and scuffing have added themselves. While the US steel tracks would have rusted as much as any other nation in the long run, using a black base primer allows the characteristic U shaped chevron to show up really well.

It is worth spending precious time texturing and weathering the spare tracks hung on vehicles, but unless the vehicle is a static model for display, the work done on running tracks won't survive ten minutes in the garden!

Looking at museum vehicles, I have noticed that the alloy steel of the tracks varies from country to country and period to period. Geman WWII tank tracks often appear to have a dark brownish base tone, while British cuiser tanks all seem to have a very blackish patina to the bare metal surface, and I understand this was due to the higher manganese content. Always worth taking photos of any real examples.

It is all a bit subjective anyway, so people will disagree and there is no definative "look". Have fun.!

cheers, Fabrice

[David Makaras]

Hi Steven,

A couple of years ago I was watching one of the home improvement/reno shows here in Oz. One of the designers created some garden art that incorporated some sort of "paint" (possibly clear) which contained iron elements. Once painted on the relief/sculpture, they added an oxidising product which created a rust effect which looked realistic.

While I would hesitate using something like this on my model due to concerns about chemical reaction, it might be something worth experimenting with. Perhaps someone else on the forum has greater knowledge about this type of product.

Cheers...

[Allan Richards]

I think it really depends on what you want to model. I get to see some of our tanks that are still regularly used in service and their tracks are not that rusty. The horns and areas of the track runing with the wheels gets quite polished and on the tread side the rubber blocks get chewed up and dirt gets in the crevises of the track links. One must remember that most of the early WWII tanks are now static or spend almost 100% of their time idle, so the tracks are bound to rust if the vehicle is left in the open. As Fabrice says the traks on any Armortek model that runs regularly get scuffed up and dirty very quickly. On my Tiger 1 the track pins started to jam into one of the links from corrosion, either through leaving them dirty or presure washing them. I now take the trouble to remove them after runnng in the wet and place them in diesel oil for a couple of days to minimze the corrosion and keep the pins free. The paint has long since gone, but they have developed a patina of their own.

[Fabrice Le Roux]

Ah yes!

I overlooked track care. As Allen says, hose them off, dry them (hairdryer is good) and lube (some prefer dry lube products, whatever!).

The two very dirty words hereabouts are:

GALVANIC CORROSION

Unpainted steel and aluminium in direct contact will, electrolytically, interact to produce corrosion (the aluminium breaks down), even when dry. Add water; the process happens faster. Add salts or common earth minerals (aka mud); it starts within minutes. Leaving the vehicle overnight will develop visible corrosion.

This is the same problem that aircraft owners have faced since the introduction of aluminum skinned aircraft (a former hobby of mine). I do not have a permanent solution for our tracks. Cleaning, drying, and lubication slows the onset, but metal to metal wear is unavoidable in the simple dry pin design of our models. Alternative metal alloys either would be prohibitivley expensive or impose a severe weight/performance penalty. Mark has done the best job possible at an affordable cost to his customers and it is up to owners to look after their models as best they can.

Enjoy the challenge. Track care and maintenece was and remains an authentic bugbear of real tank crews!

Cheers, Fabrice

[Brian Leach]

Hi all,

Just though i would give my two cents, or rather spurr someone on...

If I remember ccorrectly, Roland had Titanium pins made up.

Did that help with the corrosion problem?

Expensive? I cannot remember if the Ti made the galvanic action worse or wasn't apparent. The F-100s i worked on had no galvanic corrosion that I was aware of, but I was avionics...

Roland, How are your tracks?

Brian

[Roland Mann]

Hi all involved with track questions. Beeing aware of the galvanic problems before assembling my tracks I desided for tinanium pins. After all the time in dry and wet I never cleaned my tracks. Just waiting for the dirt to dry and than it falls off. A lot of work it was to do the pins but not expensive at all. At the time when I was looking for the pins in ebay some one involved in the hugh volume production of chirugical bolts in diameters like 3 to 6 mm offered the rest of materials from a CNC automatic lathe in lenghts like 150 to 200 mm. So I bought 250 left pins for the pins and 50 for the end rings in 6 mm Ø. For very cheap money. Now the tracks are still as new and for track tention I have only removed one track on each side to eliminate some early setting.

So I'm absolutely happy with my track pins and with my tracks. If I had to do it for another tank - yes I would.

Roland

[Brian Leach]

Roland,

And they look great too!

Thank you Professor!

Brian