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Armor/AFV: Canadian Armor
Discuss all types of Canadian Armor of all eras.
Hosted by Darren Baker
Churchill MK III at Dieppe
tankmodeler
#417
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Ontario, Canada
Joined: March 01, 2004
KitMaker: 3,123 posts
AeroScale: 1 posts
Posted: Wednesday, July 18, 2018 - 06:42 AM UTC
This is all very dependant on _exactly_ what alloy is being discussed.

The manganese steel tracks on the Canadian Mk VI Valentine at Camp Borden, ON, is a matte grey. No brown/bronze tinges at all. Simple plain mid grey. Never painted, no streaking of corrosion, nothing and it sat outside for over 60 years.

Small variations in the alloy composition of manganese steel from various foundries can easily produce significant variation s in appearance (of no importance at the time) and of corrosion (of not a whole lot of importance at the time) and wear rates (of highest importance at the time.

Both sides of this discussion can be quite correct and there is no way of telling which would be more representative of tracks at the time without numerous, period, colour-balanced photos. Which we're never going to get.

What we do know is that tracks that did rust dis so very soon after the vehicle halted, especially in moist climates and we also know that within a few hundred meters of motion, surface rust was essentially all gone from any contact surfaces, including crevasses for tracks running over anything other than hard finished roads.

Other than that, let photos be your best guide and cut "the other guy" some slack for his interpretations.

Paul
Das_Abteilung
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United Kingdom
Joined: August 31, 2010
KitMaker: 365 posts
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Posted: Tuesday, July 17, 2018 - 06:51 AM UTC
The Churchill picture posted above illustrates my point. The wear points on the spuds show the brownish shade I mentioned: a bit like bronze but not quite. The main oxidation (call it rust if you like) visible on most of the links is the grey-brown colour I mentioned.

Yes, there are some small spots of orange rust here and there. But that's after, what, 70 years - even allowing for years of indoor storage? Those could be the result of alloy imperfections or surface contamination by an aggressive corroding agent such as salt or even inappropriate cleaning agents.

For non-lubricated parts the only safe cleaning agent on museum military vehicles is distilled water. The effect of other agents is not properly understood.

Here's a picture of a Tortoise track for comparison. I don't have any of my own photos of any Churchill track.
sgtreef
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Oklahoma, United States
Joined: March 01, 2002
KitMaker: 6,043 posts
AeroScale: 80 posts
Posted: Monday, July 16, 2018 - 01:16 PM UTC

Quoted Text

Except that being high-manganese steel like all British tracks they didn't wear to a graphite or steel color and they rarely displayed orange rust.

Worn areas of manganese steel tracks are a goldy-brown metallic color that is very hard to represent accurately. But it is neither silvery nor graphite.

Oxidation gave a grey-brown surface patina. The manganese content inhibited rust formation - for decades.

If this vehicle is one that ended up stuck on the pebble beach, I wonder if the whole of the track link surface would have been polished by the action of the pebbles, particularly if the tank had bellied and tried to free itself. It would have taken weeks or months for those worn areas to develop an oxidized patina.



All good replies, Yep 1/35 scale, my first for a Canadian tank, ever,and what it comes down to, Dieppe should never of happened, foolish move which gained squat , but a loss of over 2000 Canadian POW's, and another close to 1000 killed.

Good deal on the tracks as what I have seen , and as I have a British friend that lives in Kent, said all is well.

And I have had magnesium lawn mowers that did rust.

As to salt water I worked on a Yacht my bosses 45 Foot Chris Craft , way back in 1973,and again his 53 foot Chris craft in 1974,and steel rusts just looking at salt, unless our salt here is stronger then European salt there in France or the UK, but hey could be, and I am finished on that subject.

So with that a pic for your book.



A few more pics.





Need to do more work on the upper exhaust ,but latter down the road.

Cheers

Jeff
chris1
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Auckland, New Zealand
Joined: October 25, 2005
KitMaker: 949 posts
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Posted: Sunday, July 15, 2018 - 04:08 PM UTC
Hi Jeff,
Please tell me this is 1/35th? If it's 1/72nd WOW.


Chris
redcap
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England - East Midlands, United Kingdom
Joined: November 06, 2005
KitMaker: 753 posts
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Posted: Sunday, July 15, 2018 - 12:59 PM UTC
Really nice work so far.

Gary
Das_Abteilung
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United Kingdom
Joined: August 31, 2010
KitMaker: 365 posts
AeroScale: 0 posts
Posted: Sunday, July 15, 2018 - 11:35 AM UTC
Except that being high-manganese steel like all British tracks they didn't wear to a graphite or steel colour and they rarely displayed orange rust.

Worn areas of manganese steel tracks are a goldy-brown metallic colour that is very hard to represent accurately. But it is neither silvery nor graphite.

Oxidation gave a grey-brown surface patina. The manganese content inhibited rust formation - for decades.

If this vehicle is one that ended up stuck on the pebble beach, I wonder if the whole of the track link surface would have been polished by the action of the pebbles, particularly if the tank had bellied and tried to free itself. It would have taken weeks or months for those worn areas to develop an oxidised patina.
Vicious
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Queensland, Australia
Joined: September 04, 2015
KitMaker: 1,517 posts
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Posted: Saturday, July 14, 2018 - 10:47 AM UTC
WoW...The traks are spot-on!
sgtreef
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Oklahoma, United States
Joined: March 01, 2002
KitMaker: 6,043 posts
AeroScale: 80 posts
Posted: Friday, July 13, 2018 - 12:51 PM UTC
Thanks Paul,used a spray of Tamiya Dark brown ,followed by a coat of Monroe pigments. Just playing around with the colors, I have a set of 5 rust colors from them.

http://monroemodels.us/aim.weathering.htm

But first I started with a coat of Sophisticated Finishes Rust, which was the base coat after the painting the model color.

http://www.misterart.com/crafts/decorative-painting/faux-finishing/triangle-coatings-sophisticated-finishes-metallic-surfacers.html

Cheers
tankmodeler
#417
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Ontario, Canada
Joined: March 01, 2004
KitMaker: 3,123 posts
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Posted: Friday, July 13, 2018 - 04:35 AM UTC
Nice rust job. What paints and method are you using?
sgtreef
_VISITCOMMUNITY
Oklahoma, United States
Joined: March 01, 2002
KitMaker: 6,043 posts
AeroScale: 80 posts
Posted: Thursday, July 12, 2018 - 12:42 PM UTC
Well thought I would do this up while waiting on another model to show up.

Cheers