My Beaut Aussie Cent

Stephen White · Post by **Stephen White** » Sun Jun 16, 2019 11:57 am

Phil, yes, the final stage will be a unifying overspray of a darker dust shade, probably in about 2025 at the rate I'm going.

I'd like to show why I think oils are such a powerfully flexible medium for weathering. I started on the turret sides, with the simple process of rendering the light and shade and then applying operational effects, mud, dust, streaks etc.

First the light is applied and blended, then the dark:

Then some operational effects:

It's quite hard to capture on film here the true hues, shades and intensity of the weathering but at that stage I did what I should have done earlier and stood back to admire. I realised I'd fallen for the oldest weathering fail in the book, I'd overdone it. It looked childish:

This is why I like oils for weathering, they are so flexible. I was shown a technique by Spud Murphy, who is a top modeller in 1/35th and a former model magazine editor. He paints in acrylics but will use a distressing technique wiping away excess weathering with a cotton bud.

After some judicious wiping, a much more satisfying and realistic result. This is before applying the dust overspray, so the final result will be more subdued:

Phil Woollard · Post by **Phil Woollard** » Sun Jun 16, 2019 12:03 pm

Starting to look really good! One tip when you wipe or rub away (looks like you are aware of it anyway) is to always wipe or rub with gravity, ie down the plate as the water would run, more difficult on a flat surface of course!

Stephen White · Post by **Stephen White** » Tue Jun 18, 2019 1:49 pm

Last two stages for the left turret side. Rendering and operational effects are done, with oils and pigments but the result is too stark. A feature of almost all the photos of Australian Centurions in Vietnam is a heavy layer of a reddish dust. This is the last layer to be applied.

As each sub-section is done, I've dusted on a very well thinned overspray of acrylic. The shade of the first application was too light and the latest coat is much darker and redder in hue:

Once applied, the dust layer can be removed from any areas which would get constant use, with an environmentally unfriendly cotton bud dampened with X-20A.

One comment on the photos, the hard white artificial light is amplifying differences in shade. In natural light, it will all look more subdued. Honest.

Stephen White · Post by **Stephen White** » Sun Jun 23, 2019 4:17 pm

Interesting battery issue at the Weston Air Pageant yesterday. I run a Tracer 24V 20Ah LiFePO4 battery which has a battery management system to provide over-charge and over-discharge protection. The maximum continuous discharge is 30A and peak max is 60A. The battery was well charged to 26.6V although the max charge is 29.2V.

The running surface was dry, short grass with a loose sandy soil. I'd been running successfully for about ten minutes with a lot of manoeuvring to avoid the crowd when I lost all power, suddenly and without warning. I've got telemetry and the last voltage reading before the cut-out was 25.9V. The battery's spec includes a minimum voltage of 16V, at which point the BMS will cut in.

Tracer batteries also come with a so-called fuel gauge and none of the LEDs were illuminated, which I've never seen before. The gauge is connected in parallel with the two output leads. A voltmeter showed 5.86V.

Discussing it with Adrian Harris, we could only think that an over-voltage condition had occurred and the BMS had shut the battery down to protect it. Working on that theory, we left the battery for a while to see if any power was restored. No result. We then applied a charge and after 5 minutes, disconnected and re-tested. The battery showed 26.2V and the "fuel gauge" showed all LEDs illuminated.

I"ve asked Tracer Technical Support for comment but I suspect the answer will be as we thought at the time. The BMS acted as advertised to protect the battery. It only re-sets itself when a small charge is applied.I draw three conclusions from this:

- LiFePO4 batteries are inherently safe, unlike LiPo, and are well suited to our models. The BMS protects the battery, whereas with lead acid, an over-discharge condition may damage the battery permanently.

- I believe that tests have shown that the peak discharge for the current Armortek system is probably around 30A. This incident suggests that with the heavier models, a greater peak discharge might occur.

I believe this is much more relevant for the forthcoming Chieftain, which will be the heaviest Armortek model yet. The revised electrics are being upgraded to accommodate this but there is probably a need to establish the impact on battery selection. I intend to convert the Centurion to an FrSky Taranis X9D Plus radio system, which is a computer radio capable of data logging. It would be very pertinent to build up some data on amperage to establish just what peak conditions apply on different running surfaces, in anticipation of Chieftain's arrival.

If Tracer come up with anything different, I'll update this post.

Christoffer Ahlfors · Post by **Christoffer Ahlfors** » Sun Jun 23, 2019 7:09 pm

Overvoltage? Under load? Or were you running downhill, so that the regeneration could indeed have caused an overvoltage?

Stephen White · Post by **Stephen White** » Sun Jun 23, 2019 7:38 pm

Christopher, the tank was on level ground,acceleratingr and turning. The regenerative power system would not have been in operation. I know Mark Watkins did question whether LiFePO4 batteries could cope with the amperage seen with regenerative power systems but given that the peak max voltage for this battery is 60A, this hasn't been a problem.

Stephen White · Post by **Stephen White** » Wed Jun 26, 2019 7:09 pm

TankFest set up day tomorrow, a stimulus to complete the weathering. Just a few tweaks now to do in slow time. I'll catch up later with some more methods, including using metalised pencils and combining oils and pigments.

Stephen White · Post by **Stephen White** » Wed Jun 26, 2019 8:41 pm

Two more weathering techiques.

Usually, the rendering is done with oils and then, once all the oils are fully blended, the operational effects are applied using pigments and further oils. The difference between our modelling and the 1/35th plastic modellers is the need for our paint finishes to be robust and capable of handling outdoors. That means pigment fixer has to be applied. There is a pitfall here, if too much fixer is used, the finish can have unsightly tide marks, which you then have to cover up with more pigments or oils. The tide marks show up in this photo;

One technique for avoiding this is to combine a wet application of oils and the pigments. To do it, the oil rendering isn't fully blended. Although the linseed has been soaked away on card, the oils still remain soft for a few hours. This gives an opportunity to apply the pigments directly to the damp oils. They are then stabilised sufficiently to be able to spray fixer on with an airbrush, without blowing the pigments away. It's a good technique, if you're sufficiently confident with the rendering stage not to blend fully. The joy of oils is that they are infinitely adjustable and in the last resort, they can be wipe away to start again. This isn't a subtle technique, it produces pretty strong effects. It is probably best restricted to the areas where the operational effects are likely to be most intense, such as horizontal surfaces. Otherwise, it's too easy to overdo the weathering.

Here's the techique:

: Light oils rendering

: First pigment applied to the damp oil

: Further pigment colours added and fixer sprayed on

: Darker rendering oils and further pigments applied

: Final result with a light dusting of Tamiya laquer to represent dust

Another refinement, using a silver metallised pencil to sharpen up edges where wear might take place.

Stephen White · Post by **Stephen White** » Wed Jul 17, 2019 5:45 pm

This photo was taken in Vietnam in 1969 by Sgt Sandy Tocock, who commanded the ARV of B Sqn, 1st Armd Regiment. Sandy Tocock would have been in theatre at the same time as My Beaut Aussie Cent and David Hay and his crew. Although I don't yet know which tank is on the bridge, I couldn't rule out that it could be 22B.

With Adrian Harris' newly acquired Centurion Bridgelayer available at Yeovilton, it was obvious we had to re-create the picture:

To prove it's a small world, Sandy Tocock's son Roger has just commented on the photo on Facebook:

https://www.facebook.com/groups/134672933274865/

Mark Heaps · Post by **Mark Heaps** » Wed Jul 17, 2019 7:03 pm

Fantastic tutorial on how to achieve weathering effects but I would caution on over-doing it.

Museum pieces having accumulated rust and oil-stains over all these years do not accurately the vehicles as they were used in combat.
For World War 2 vehicles, I would suggest the most you want to simulate is 2 years usage. Any longer than that and they were either obsolete and taken out of service or up-graded.
For the Chieftain, I would suggest up to 6 years light usage. In the 3 year tours I did with Chieftain and Challenger units, I saw half the squadron worth of tanks being repainted during that time.
Weathering for me should be the dust, dirt, and mud that accumulates during use in the field. Odd dings, dents, scratches with minor rust also acceptable. The odd minor oil leak also acceptable and realistic as long as it is appropriate to the vehicle. Oil leaks were regularly checked by the crews and the area wiped clean to monitor future leakage. Any oil stainage more than 2 weeks old indicates a poorly maintained vehicle or a museum piece.

I would suggest the look you want to achieve is that the vehicle looks well-used but maintained, dirty from the environment but clean where it should be if the crew are looking after it.

Adrian Harris · Post by **Adrian Harris** » Wed Jul 17, 2019 10:37 pm

I love how you've Austeracised the picture, makes it impossible to tell the scale

Adrian.

Stephen White · Post by **Stephen White** » Thu Jul 18, 2019 5:50 pm

At the risk of flogging a dead horse, I've played on Photoshop with the "Austeracised" image of Adrian's Centurion Bridgelayer and my Beaut Aussie Cent. This was the original 1969 photo, enhanced as best I can:

The photo was taken in August 1969, at the same time as I've tried to portray "my" Aussie Cent, 22B. The tank on the bridge was commanded by 2/Lt Chris Sweeney, Troop Leader of Four Troop, B Squadron, 1st Armoured Regiment. The troop were well into their tour by then and very experienced. The location is near the village of Xuyen Moc, Phuoc Tuy Province. Sweeney had assessed that crossing the dried river bed was too risky and had ordered Sgt Nicholls, commanding the bridgelayer, to overbridge the remains of the destroyed bridge. Once 4 Tp were across, Nicholls picked up the bridge and they proceeded on their way.

Although we know the tank on the bridge is commanded by Sweeney, its identity is uncertain. He would normally command callsign 24, which is listed as ARN169077 in July and September but in August it was with 1Tp. The other tanks in 4 Tp were 169007 (24A); 169104 (24B); 169041 (24C), so it's probably one of those, not "my" 064 sadly.

It's most likely that 4 Tp were engaged in supporting 6th Battalion, Royal Australian Regiment on Operation MUNDINGBARRA between 15th July -15th Aug 1969. The mission was to deny cover to enemy forces in the approaches to the Long Hai Hills, an enemy base area with bunker systems. There is a connection here with 22B, as 2 Tp, C Sqn, provided the armour support to Operation HAMMERSLEY, in 1970, which saw the Australians assault into and largely clear the enemy base area in the Long Hais.

Rural Vietnam has changed out of all recognition in the last 50 years and that presents a challenge in locating the site of the bridge in the photo. This is a contemporary map dating from 1968, showing the probable location, noted on the map north east of Xuyen Moc as "destroyed ford":

and today, a major road and new bridge has replaced it, while Xuyen Moc is barely recognisable:

Nevertheless, this is probably the site of the photo. Bruce Cameron, in Cannister, On, Fire, has a photo taken shortly before the one above, showing SGT Nicholls laying the bridge:

and this is the our modern day version, Adrian's Cent Bridgelayer and my Beaut Aussie Cent:

Mark Heaps · Post by **Mark Heaps** » Thu Jul 18, 2019 7:17 pm

Stephen White wrote: ↑
Sun Jun 23, 2019 4:17 pm
Interesting battery issue at the Weston Air Pageant yesterday.

If Tracer come up with anything different, I'll update this post.

Interesting issue, being ex-REME, I want to know the quickest way to rectify the fault should it occur. Do you need to connect it to a dedicated charger which could be a problem if you are far away from the nearest power socket ? Or could you flash it with jump leads from a car battery , and reset the fault that way and get the tank back into action ?

Mark

Stephen White · Post by **Stephen White** » Wed Sep 11, 2019 2:58 pm

Mark, apologies for not replying sooner. It seems it's sufficient to flash the BMS with a 24 battery briefly, although the manufacturers insist it shouldn't be necessary and all that's required is to reconnect. I've had a 6S 1300mAh 85C lipo around for model aircraft and will carry it in my tool box. This has so far been an isolated event, very hot day and running (turning) on grass, so I'm confident the LiFePO4 batteries are pretty robust for our needs. It will be interesting to see what amperage is demanded with the new Chieftain motion packs and whether that comes close the the maximum theoretical load before the BMS protection activates.

Stephen White · Post by **Stephen White** » Wed Sep 11, 2019 4:23 pm

Time to apply one more small but significant detail. On the 6th June, 1969, ARN 169064 was hit by two North Vietnamese Army RPG-7 rocket grenades during the Battle of Binh Ba. The first struck the resilient rail in the rear left corner of the hull, the shrapnel wounding the crew commander, CPL Barry Bennier. The second, more damaging strike, hit the turret on the right front, just above the mantlet. It penetrated the turret and set fire to the mantlet cover, dousing the driver, Bill Morris with burning canvas. The turret penetration wounded the commander again and both the operator, TPR David Hay and the gunner, TPR Peter Matushka. You could infer from the two hits that the tank was surrounded by enemy infantry in the village and was under fire from very close range.