Minenraumpanzer III

Minenraumpanzer III

That Wacky Mine Clearer

DML/Scratchbuild, 1:35

Those wacky Germans. Always dreaming up new and interesting vehicles and then building them. The above-pictured vehicle was actually built by Krupp during WWII. The vehicle was raised about 18(?) inches by adding extensions to the running gear arms. This was thought to give the crew a bit of protection by providing more distance from exploding mines. The pancakes in front were meant to explode mines in the path of the vehicle’s tracks. Turning this thing would have been a ton of fun. Now if you think those wacky Germans had the monopoly on strange mine clearing devices, you should see the American version of this same concept on a Sherman! Don’t worry, I’ve already started cutting plastic for that one.

In The Beginning

The DML Panzerkampfwagen III Ausfürung G kit was used as the basis of this conversion. Photos of the real thing as taken by the U.S. Army (I guess) show the use of early sprocket and narrow (36cm) tracks, which this kit has. The real meat of this conversion are the extensions on the running gear. There are no plans that I know of out there, any dimension drawings, or written descriptions of it. So what do you do? Scale off of the photos. First get a copy of a large, clear photo of the running gear. Now draw a vertical line through one of the wheels. We know the diameter of the wheel. If the distance to the center of axle on the wheel to the center of the axle of the torsion arm is X times the radius of the wheel, we know a dimension that we can start sketching out the extension from. The rest of the extension design came from common sense. Now that I have it designed; I built one out sheet plastic complete with weld seams and depressions for the axle. I figured that I would be casting at least 8 copies out of resin, and I wanted a nice, detailed master.

The Mold Trauma

This was the first time I had tried casting in resin. I picked up some two-part RTV (Por-a-Mold) from the local ceramic shop. It was the middle dense type for low temperature casting. I didn't’ know how hot curing resin can get and I figured on using an open-faced one-piece mold. So I built up a small plastic box to act as my reservoir, laid my master in it, mixed the RTV, poured it, waited, and I’ll be damned, the stuff didn’t set! I waited some more (a week) and the stuff remained soft. I guess I didn’t mix the two parts well enough. So I tried again and again until I had a mold that worked. Now I tried casting. I mixed equal parts of Alumilite, poured it into the mold and came out with a decent reproduction of my master. After three more pours, I noticed that the casting were starting to look a little rough, like cast iron. Hmmmmm. My mold was deteriorating. So soon! I made another mold, cast more pieces, and again after three or four castings, the deterioration set in. I ended up making four molds that worked and casting 24 extensions. Out of 24 castings, I found 8 that were halfway decent. Even then, I had to do a lot of sanding and cleaning to get those eight into usable condition. I tried casting other things from the middle dense RTV with the same results. I have theorized that the resin was reacting somehow with the RTV. I should have bought something denser or for higher temperature materials. Now I use the red, high temperature RTV for car gaskets. This stuff comes in tubes and is available from your better car parts stores. This tends to last at least 100 casting and is cheaper than the two-part stuff. Unfortunately, it is really only useful for making open-faced molds. One interesting footnote to this debacle, I put the useless castings in a box with other plastic parts for a few months and they melted into the plastic parts. I don’t know why. The ones on the model seem okay and are not melting the wheels. If anyone out there knows why, I’d like to hear from you.

Running Along

Plastic tube was used to replicate the bearing sleeves at the top of the extensions. I used strip plastic and sliced rod (you know, like slicing carrots) to make the flanges on the sleeves. The kit swing arms were attached to the lower hull and allowed to dry. The hull was then placed on a stand with enough room for the extensions to hang freely underneath. Then the extensions were fitted over the axle stubs, carefully lined up and superglued in place. The wheels had their inner faces painted dark earth, assembled and added to the extension arms. I added wheels on the four corner arms first. Now rest the vehicle on a perfectly flat surface on these first four wheels and slide the remaining wheels in between the extension arms. Let the wheels move vertically until all the wheels are resting on the ground, then zap them with superglue. This ensures that all the wheels are level and in contact with the ground. Otherwise I would have to create a muddy diorama base to hide my mistake. I bought two sets of white metal 36cm track links from Mini Art out of Hong Kong and added these to the running gear with superglue. This adds immensely to the strength of the running gear. Sheet and strip plastic was used to recreate the rest of the running gear supports and shields. Again, I scaled dimensions off of photos and used more sliced rod for rivets. I painted everything Polly S Mud to simulate dirt, but not mud. For mud, I would have added talcum powder or real dirt to the mix.

The Upper Superstructure

I built up the rest of the hull and superstructure according to the kit instructions. The side escape hatch on the right side of the vehicle was opened up. The hatch is from R&J Enterprise's Pz III hatch set. These have nice detail on the inside of the hatch and a pattern to make the opening in the hull side. I sealed up the turret hull with the resin blanking piece from the Verlinden Bergepanzer IV set. A lot of the other minor details were also robbed from this set. I added various spare parts and brackets from Modelkasten’s Pz III sprocket and StuG III/Pz III set, tools from Tamiya’s Pz IV OVM set, and miscellaneous Pz III parts from the DML kit itself. I figured that this type of vehicle is going to get blasted to bits a few times and will need a lot of spares. I also added various electrical conduits from fine solder.

Minenlaufwerk

The mine roller works (minenlaufwerk) was based on a photo of a mine roller attached to a regular Pz IV. I cut the 1" diameter discs from 0.020-sheet plastic with a compass for the rollers. Spacer discs were punched out of 0.010-sheet with a hole-puncher, then alternating roller/spacer were fitted to a plastic rod axle. Arms were built from (yes again) strip plastic.

I know that in some areas of this article, I am being vague about what size plastic strip and rod I am using, and there is a good reason for that. I don’t remember. This was built about two years ago and I can’t remember what sizes I had on hand. I generally buy whatever sizes look useful and throw them all into a big pile. I then thumb through the pile until I find something that looks reasonable.

The attachment point on the hull front was built up according to photos from 0.080 thick plastic sheet and tube. It seemed to me that the mine roller arms would attach to the vehicle the same way backhoe arms would, with a large universal joint controlled with hydraulic pistons. The pistons were made from two sizes of plastic tube and attached to hinges (sheet plastic wedges with sliced rod to replicate hinge pins and locks.) Hydraulic lines were then added to both ends of the thicker part of the pistons. These are two-way pistons, able to pull and push.

Paint That Panzer Gray

The vehicle was painted as construction went along. The lower hull and running gear was painted with Polly S Mud and the upper hull and superstructure in Polly S Panzer Gray. This Pz Gray seems a bit light to me, but after a wash of dark umber oil paint, it will look all right. The Minenlaufwerk was painted Polly S RLM 66 just to give the colors a break from Pz Gray. Don’t be like me and assemble the rollers/spacers without painting in between first. I thought my brushes would reach down in between, but they don’t. ARRRRGGGHHHH! Anyway, all painting was handbrushed with Tamiya brushes. The turret blanking boards were painted dark earth, tool handles in red brown, and the metal parts of the tools were painted Metalizer titanium. The edges of the tools were then hit with Metalizer steel and aluminum to show wear and tear.

Weathering Heitz

The entire vehicle was then doused in a wash of Durotine (an odorless less toxic version of turpentine) and Dark Umber oil paint. Drybrush with gray then with light gray oil paint to bring out the details. I wanted to depict rust all over the vehicle. I first used orange chalk pastel, but the color wasn’t dense enough. Then I read (?)Makoto Takeishi’s article in Armour Modelling about using Tamiya Thinner and chalk pastels and it worked beautifully. Basically, create a small pile of pastel dust, then dip your brush in some clean thinner, thin into the pile of pastel dust and apply to small areas of the model. The thinner dries leaving bright orange rust streaks. Of course not all rust is this new bright orange color. I then mixed up some black, red, brown and orange and used this for older rust. This is also useful for weathering prepainted rust on mufflers and rusty cars. This method can also be used as a wash instead of using oil paints. I added dark brown pastel directly to the model to depict dust on the hull sides and running gear.

Did I Forget Something?

And that’s all folks. I don’t really know what drove me to want to build such an ugly thing. I built what I thought would be an operational vehicle. I still feel like something is missing, but other than a decent base, I’ll stop working on it here.

Page created August 19 2002.