Thursday, 23 March 2017

Casting: Making the mould

Well I promised you guys that I would walk you through my learning process as I attempt casting models to a level of quality that I would be proud to sell to my fellow modellers and gamers.

Nothing professional here, but more a desire to have decent looking models as opposed to whats out there and available for the Black Brigade. 

So we have already had a look at the gear list that I have had to put together in order to be able to start knocking out all of this stuff that I need. Its now time to start using it.

First stop was the vacuum pump, and I have to say that this was a real ball ache.

The Vacuum Pump

The Pump that I bought must have been an end of line piece of gear as they don't manufacture it any more and it is absolutely impossible to find instructions on how to use it online. All I have is a German language instruction booklet that was produced in China and was delivered with it!

Thankfully my significant other is fluent in German

Any excuse to get some exposure! She made me do it!!! :D
However, the diagrams do not point out vital elements on the schematics and the German descriptions turn out to have a generous spattering of Polish in them as well.

Poor show!

After wrestling with it for an hour or so I FINALLY worked out where to put the oil into... and had to spend an hour and a half pouring oil into it! I ended up resorting to a micro funnel with a cocktail stick stuck down the middle of it to get the oil into the pump without air bubbles causing constant spillage! 

WHAT A BITCH!!!! No wonder they don't make it any longer! Incidentally all of the other ones that you see now online all have Oil Intake Ports on the top of the pump so my problem will no longer be anybody elses!

After testing the pump to make sure it did what it says on the tin (so to speak) the next step was to prepare the prototype for making a mould around it.

I've chosen to do the soft back for the Polski Fiat 621 truck. The reason for this choice is that its a simple exercise in learning a process. Very little undercutting and not much surface detail that isn't bass relief. Should be something easy to pull off... and as I need so many of them anyway I thought it would be a good place to start.

This process is called Drop Moulding and is probably the most simple of Moulding processes. Simply put you just drop liquid Silicon over the prototype in order to create the mould. 

The very first thing that needs to be done is to measure up a base board and trial fit a Lego retaining wall to the board which will create the receptacle for pouring the silicon into which will actually create the mould.

Once the board is measured up cut it with a healthy border surrounding the Lego.  Its important that the mould base board can fit inside the Vacuum cylinder otherwise you wont be able to degas the mould.


Once everything is measured up the first thing to do is to glue the Lego bricks to the base board so that there is no chance of any of the Silicon bleeding through under them and ruining the mould. To make it easier for the Glue Gun to reach the bottom of the bricks only use two layers of bricks initially.


The next step is to but a Blue Tack 'funnel' onto the bottom of the piece to be moulded. This Blue Tack fills three functions. Firstly, it creates a tight seal of the item to its baseboard so the mould integrity is not compromised by creating flashes and invasions of silicon where you do not want them to be. Secondly this Blue Tack actually creates the 'funnel' through which you will ultimately pour your resin when you are casting new copies. Thirdly this 'funnel' creates a receptacle for extra polyurethane resin which, when you degas each new casting, will provide enough extra resin to ensure a perfect casting when the elimination of the gas bubbles within the casting depletes the extra resin as it takes the place of the bubbles. 


Depending on the viscosity of the resin this may be a negligible amount BUT personally I would rather have more than not enough to cover this possibility.

The next thing to do is to press this Blue Tack funnel to the Moulding Base Board to ensure that there is a tight seal all the way around to prevent silicon leakage.


The final step in the preparation of the mould is to build up the Lego retaining wall to a level that is higher than the piece to be moulded ensuring that it is high enough that the mould will have a solid and sturdy base once the silicon is cured.


...and there you have it. The Mould is now ready for its silicon to be poured in.

... and that's where everything became touch and go!

So having finally received my two giant syringes (which I believe in a former life may have been used to impregnate Diplodocus' in Jurassic Park!) I allocated one syringe for the Catalyst and one for the base of the Silicon. So long as they are only used on what they are labelled for the liquid will never cure and so the syringes will be reusable.

Now this silicon is supposed to be extremely fluid, which is the main reason that I bought it BUT when I drew it up into the syringes (same for both parts) it was as liquid as Golden Treacle! That's thicker than Maple Syrup to all of you Yankees and Cannucks out there ;) This worried me a bit as with all of the undercuts on these models I thought that this may present a serious problem as I attempted to make these moulds.

I drew up 80ml of each of the two liquids and deposited them into a mixing pot. This Silicon is addition cured which means, amongst other things, that you can measure it by either weight or volume so long as its a 1:1 mix. Happy days! I gave it a good stir in its mixing pot and then put it into my vacuum chamber to be degassed. Thankfully as I stirred it around it also became more fluid as well so it may not come with the casting issues that I was stressing about.

Now, this is the first time I have ever used a vacuum pump in anger so the results were perhaps predictable. I sealed the chamber and switched on the pump...then sat there watching the pretty air bubbles rising to the surface of the silicon. I bled the air out periodically and then when I decided I had done enough degassing I did a final opening of the air valve... unfortunately I opened it immediately and completely not knowing that it would also bleed air into the cylinder straight down into the silicon... which exploded all over the vacuum cylinder! Doh!!!

Silicon Explosion after catastrophic re-gas!

Thankfully I had made enough to still complete my task so I took it out and poured it into the mould wall containing the prototype. Still pretty viscous but I angled the mould and poured slowly into the bottom corner allowing the silicon level to rise under the undercuts of the prototype levelling the mould to the horizontal only when the silicon was in danger of spilling over the top.

Mould after the initial pour and before degassing.
Once the mould was filled I could see that there were an incredible amount of air bubbles still in the silicon so I decided to put the whole mould into the vacuum chamber.

This time instead of degassing and re-gassing cyclically I decided to leave the pump on for a good thirty seconds or so until all of the air bubbles had been drawn to the surface only bleeding air into the chamber slowly and only when it looked like the silicon would pour over the surface of the bricks.

Degassing the mould. You can see the remains of the silicon explosion to the right.
When I finished degassing I took the mould out and noticed that the majority of the air bubbles (of which there were millions!) that were left were laying on and just under the surface of the mould and so wouldn't affect the integrity of the mould detailing so I was happy about this at least.

I also realised that I probably had enough silicon left in the pot to do another small mould and so I knocked up a mould for my Polski Fiat 508 Lazik Staff Car as well, and went through the same process with one exception. I stopped feathering the gas tap and just let the chamber do its work for longer periods. The results were much MUCH better!

Both moulds being left to cure after degassing.
Something else that became obvious after I sat there watching the moulds cure was that despite the silicon being extremely viscous the air bubbles that are initially trapped in it will still slowly rise to the surface and burst. I wouldn't want to bet my mould detail integrity on this though because any excuse at all to trap an air bubble will be taken I think BUT it is a help.

The state of the moulds after an hour.
Looking at the photo above we can see that whilst the initial mould still has plenty of gas bubbles the smaller of two moulds, the second mould has almost none, and those bubbles that are there are all tiny and near the surface.

On the silicon tins it says that the de-mould time is 2.5 - 3 hours although I will probably play it safe and just leave the moulds until tomorrow before I remove them.

...

Well after three hours the silicon was nowhere near cured, in fact it was only just reaching the 'tacky' stage. This did cause me some concern as I left for work wondering whether or not the moulds would cure at all.

Flash forwards to 6am and I arrive back home to find some beautifully cured moulds with absolutely no air bubbles inside the silicon at all.

The two finished and cured moulds, labelled, with the prototypes next to them
The prototypes were surprisingly easy to release from the mould. Looking inside the mould I couldn't find any evidence of air bubbles spoiling any of the detail either so I can say at this point that I would consider this to be a successful first venture into the heady world of casting miniatures.

A look at the detail inside of the mould
So, the next thing to do would be the actual casting of these miniatures BUT instead of that I'm going to spend a couple of days making all of the moulds that I will need for all of the vehicles that I'm going to be casting up so that if I am over ambitious with the amount of resin I'm mixing up I will have extra moulds in which I can pour it so that it doesn't go to waste.

I'll do another blog on the actual casting of the products soon but for now...

Lessons and Observations

i) When using the vacuum pump don't keep removing and adding gas into the chamber. Switch it on and leave it on to allow it to do its work, only adding gas back into the chamber IF the silicon looks like it will flood over the top of the mould retaining wall.
ii) The Lego retaining walls should be twice the height of the pour level of the silicon if degassing is to be attempted to prevent the silicon flooding over the top of the walls.
iii) Even though the retaining walls are glued to the base and the bricks fit tightly against each other the vacuum chamber will pull silicon through the joints between bricks and base. It isn't a problem as its such a small amount but it does still happen. This is one of the reasons why you still need your border around the wall.

Now, when all is said and done... FIX BAYONETS!!!!



Wednesday, 15 March 2017

Casting: The Kit List!

...and so, after three trying months of sculpting an all together far too small a pile of Polish vehicles we come at last to the most testing of sequences in a chain of events that will ultimately lead me to being able to field the Polish 10th Motorised Cavalry Brigade; The Black Brigade in my Flames of War games... the actual mold making and casting of all of these lovely little vehicles that nobody competently makes!

So, as Im going to talk you all through my trials and tribulations that I suffer I thought it may be a good idea to provide a kit list that I have put together and explain my choices... kind of setting off on the right foot so to speak...

The Kit! (so far)

Well I guess the first thing that I would have to say is that if you are the kind of ne'er say die daredevil that wants to embark on a cast-up-your-own-miniatures mini adventure (car not included!) then you should really take stock of things because this is in fact no mini adventure at all... and not cheap either!

Check out the picture above and you will see all of the gear that I have decided is necessary to do this. It even looks like its a kick in the financial happy sacks!

However, when all is said and done I anticipate that there will be a certain gloating pleasure in completing my aims this year! :D

Fortunately where this is all concerned I had a leg up in 2015 when a Chinese manufacturer screwed up a piece of film equipment that I had ordered and I was left with a nice sum in the bank wondering what to do with it. I decided to purchase a vacuum pump from an Ebay supplier which spent a year in mothballs while I finished up other project.

The Vacuum Pump - £220

The Vacuum Pump kit

Now these things are not generally cheap BUT this particular ebay supplier (http://www.ebay.co.uk/usr/trevoralandixon2010) has been putting these kits together and selling them for quite a while at very reasonable costs. I chose a kit that had the largest vacuum cylinder that I could find as I have a French Indochina 'Dinassaut' project hoving into view next year and these are items I am intending to sell so I need a cylinder that can fit the molds for the boats.

Why use a vacuum pump? Well there are two reasons actually. 

Firstly when you are mixing up your silicon rubber ready for the mold to be made air bubbles will become trapped in the mixture due to its high viscosity. On drying some of these air bubbles will lay against the sides of your product leading to resin bubbles becoming a part of your final piece... and believe me, I know from previous experience of buying somebody elses attempts that it takes a LOT of work to disguise these errors. Its easier just to eliminate them straight from the get go. Before you pour your silicon over the prototype stick the mixture into the vacuum chamber to extract the air from it... then pour!

Secondly if anybody has done any home casting before, one of the probable flaws in your produce will be all of the resin holes and cavities that plague your vehicles. This is an inherent problem with drop casting and is caused by bubbles of air being trapped against the sides and undercuts of the things you are trying to make. Removing the air from a casting environment reduces the size of these cavities to almost negligible sizes. Placing new casts into a vacuum pump improves the quality dramatically. The higher the viscosity of your resin, then the greater the improvement in quality of the final cast.

The Silicone Rubber - £81.95 (2kg Kit including Taxes and Shipping)


Make no mistake. Casting is expensive. A 2kg kit is deceptively small due to the weight of the component parts and the Silicon is the most expensive part of the casting materials (the vacuum pump not included of course). It is however an unavoidable expense depending the scale of the operation you want to run with.

There are two main types of Silicon Rubbers to be considered and that it Addition Cured and Condensation Cured. Each will give you a silicon rubber mold but achieve them in different ways both of which however are classified as Room Temperature Vulcanisation (it creates its own heat internally through chemical reaction).

There are a bewildering array of Silicon Rubbers on the market which we can use, for a vast range of techniques but for me I only envisage a single operational method, and thats dropcasting small scale military vehicles. With that in mind the two post important elements that I thought I needed to study up on are its elasticity and its durability.

After reading around the subject for quite a while I came across TOMPS Addition Cure RTV Silicon Rubber Viscolo 13. Its actually another organisations product but one which TOMPS have rebranded as their own and the 13 relates to its position on the Shore A hardness scale... meaning its soft! Damn soft! Owing to the degree of detail and undercutting I will likely need to take into consideration (mainly because of my tanks... look no further than my 10TP) this silicon rubber compound is widely lauded as resisting Polyurethane resins (used for the actual casting) better than any other and outlasts all condensation cured silicons and many, if not all addition cured silicon rubbers. Nice!

Testing has indicated that the molds can sustain up to three times more 'pulls' than other silicon rubbers, can usually be used without a mold release substance and can stand a far higher degree of deformation returning to its original shape...

To me this one seemed like a winner! Not the cheapest but certainly sounded like the most forgiving for what I am aiming to do. 

When I start complex projects I dont like to cut corners  because it creates bad habits. I like to get it right the first time, where possible. By buying this option I was hoping that I would achieve this!

The Polyurethane Resin - £37.04 (including Taxes and Shipping - bought off of ebay.uk)


If you get your mold making practises correct then the next big hurdle is actually the casting of the miniatures themselves.

Just as there is with the Silicon Rubbers there is also a vast array of resins to choose from. Polyester resins are the cheaper option but for relative values where casting toy vehicles is concerned then you shouldn't really look any further afield than your Polyurethane Resins.

Polyurethan Resin is easy to use and because of this it is a popular choice for anybody venturing into home casting and craft uses. It is usually opaque when cured and sets quickly with a 'pot life' of between 3-15 minutes and ready to demould after about 30 minutes. Its usually mixed by volume which means its an easier option than those mixed by weight (due to different Specific Mass' of parts A and parts B for some choices). Its proven to be less brittle than Polyester Resins and easier to work with once cured. Perhaps the greatest benefit to us model makers is that the viscosity available is much MUCH lower with Polyurethane Resins which means you can do slush casting easier and make sure that none of the tiny detailed areas get missed.

The TOMPS Fast Cast Polyurethane Resin that I chose is specially formulated to cure in thin sections of less than 1mm which other resins would struggle massively with due to the requirement for chemically driven heat in the curing process...

This resin is, believe it or not, one of the cheapest out there, which I think beggars belief when you understand the qualities that it brings to the table (so to speak). It has an uber viscosity of around 40-50cps which means essentially that when first mixed it has the consistency of milk... there is no detail that this will miss! It has a pot life of 3 to 4 minutes so you need to be quick BUT with a consistency of milk the need to degass before pouring should be unnecessary. We will see about this. Best of all perhaps is that, once cured, it has a hardness rating of Shore D 72... which means its transformed into granite! Its hardness rating that ice climbing boots soles are rated to. 

This is one attractive product!

The Release Agent - £20.99 (ordered off of ebay.uk)


When creating molds or casting from pre-existing molds it can sometimes be an advantage to make extraction of prototypes or new casts possible. Technically it shouldn't be necessary with the products that I am using but I decided that it is better to be safe than sorry and decided that a Release Agent would be better to hand than not having it at all and so it made my list!

Mold Containment Walls - £19.87 (including taxes and shipping. Ordered from ebay.uk)


When creating your molds you need to use a material to create the walls within which the molds will be poured. If using a really soft silicon rubber it will also help to have the retaining walls in place to prevent mold deformation if you aren't flush with your silicon (use a lot of it to create really wide molds). I opted to go for lego as it means I am able to create molds of differing sizes and shapes.

Scaled Mixing Pots - £11.68 (including taxes and shipping. Bought from Ebay.uk)


Mixing silicon rubbers require scaled measuring beakers which can be cleaned afterwards and then reused. I bought a large one as well so that I can degass the silicon mixture before pouring as well. Leftover silicon can be left to cure in these beakers and then easily peeled off.


Hot Glue Gun - £10.99 (including taxes and shipping. Bought from Ebay.uk)


The Mold Retaining Walls need to be fixed securely to the Casting Baseboards in such a way that leakage under the Mold Retaining Walls. This can be done by using a Hot Glue Gun to seal on the inside of the wall edge that lines the Baseboard. Nice and cheap as well!

Casting Baseboards - £6.05 (including taxes and shipping. Bought from Ebay.uk)


Baseboards are what your molds will actually be made on. You need to have a very healthy border around the mold retaining walls and they need to be durable as you are likely to use them over again. I chose MDF boards that I ordered off of Ebay.

Disposable Mixing Cups - £2.42 (including taxes and shipping. Bought from Ebay.uk)


Whereas the Silicon Rubber thats mixed up can be easily peeled off, the Polyurethan Resin that is mixed up and cured cannot. Once cured the mixing pot is essentially unusable and therefore needs to be discarded. The cheapest option out there is the disposable plastic cups which can be picked up off of ebay at a VERY reasonable price!

Electronic Kitchen Scales - £6.89 (including taxes and shipping. Bought from Ebay.uk) 


Absolutely vital to have due to the necessity to mixing the Polyurethane Resin by weight as opposed to volume due to the differing Specific Masses of the parts A and parts B that need to be mixed up and the requirement of accuracy that mixing these parts requires if a good outcome is to be expected. 

Disposable Graduated Pipettes - £3.25 (including taxes and shipping. Bought from Ebay.uk) 


Disposable plastic pipettes may be required whenever you want to mix up small volumes of Polyurethane Resins and they can be found on ebay at very reasonable prices.

Paintbrushes - £2.29 (including taxes and shipping. Bought from Ebay.uk) 


Two reasons to by brushes! Firstly any spilled Silicon Rubber can be cleaned up using white spirits on your brushes and secondly when making moulds that require a LOT of detail it can sometimes be advisable to paint the silicon rubber onto the prototype using brushes to create what is called a 'Detail Coat'. This can guarantee that none of those fine details are missed!

Mixing Spatulas - £2.95 (including taxes and shipping. Bought from Ebay.uk) 


When mixing your parts of the silicon rubber (and your PU Resin) thorough mixing is an absolute necessity so having decent mixing spatulas is advisable. With your Silicon Rubber these can be reused so decent spatulas are advisable!

White Spirits - £3.50 (including taxes and shipping. Bought from Ebay.uk) 


White spirits should be considered a necessity when embarking on casting due to the fact that the materials that you are using can be cleaned up using white spirits... and you can use it to clean the brushes that are being used on your detail coat!

there are few more bits that I've ordered to add to my kit list that I havent received yet and  which I already own but forgot to add to the photos which are:

A spirit level to make sure that the molds are curing flat.

A pouring funnel to make sure I can get my Pump Oil into the Vacuum Pump without flooding my work space

Giant Disposable Syringes so that I can draw enough of the Parts A and B for the Silicon Rubber to cure properly.

So there we have it guys, a complete kit list! Now lets see if I can actually use it without the need for summoning Great Britain's emergency services!

Nothing more to say on this other than...

Fix Bayonets!



Saturday, 25 February 2017

Flames of War: Sculpting the TKS-D tank destroyer and the Polski Fiat 508 Furgon pick up truck...




One of the really cool things about choosing the Polish 10th Motorised Cavalry Brigade (10BK otherwise known as The Black Brigade) to game with is that it has the most variety of weapons and equipment of any of the Polish formations that you can field for Flames of War, assuming of course you are using Alex's Poland In Flames unofficial expansion (Because if you are just using the Blitzkreig book to play Poland you will probably starve for a creative outlet) which goes into some serious detail about the formations that were battling over the gateway to the east or west (depending on your direction of march). This expansion, written and edited by Alexander Kawczynski (his blog is Anatoli's Gameroom), is a serious labour of love that deserves real credit.



Even Alex's tireless work on this subject however cannot cover absolutely everything. The State Police which fought over all of Poland are missing, an opportunity for the Pinsk and Vistula Riverine Flotillas was bypassed and of course there are always the little things that slip through, although this could possibly have been due to a lack of extant evidence for their use.

Me? I like to field 'whats ifs' (Please refer to my 10TP and 4TP tank blog) as well as providing a chance for the weird and wonderful if one can find an argument for them. Perhaps taking first place with these arguments is the ones for the TKD Self Propelled Gun and the TKS-D Tank Destroyer, the first tank destroyer in history.

It is likely that the TKD's that were still around were deployed with the Warsaw Armoured Motorised Brigade, and will be the subject of another blog post in the future whilst the two TKS-D's were still with the Black Brigade whom they had been with since late 1937 for field trials and deployment to Zaolzie which I will blog about with gusto here and now!

So we will start with the:

Polski Fiat 508/III Furgon

This is a small Polish utility truck that filled a variety of functions not least of which involved carrying all of the Heavy Machine Gun platoons about the battlefield. Now I have plenty of HMG's in my Black Brigade force and as such I couldn't avoid sculpting this horrible little beast any longer.

A modern rebuild of a 1934 Furgon without the spare wheels and soft top.
I just sucked in my bottom lip and got down to it...

and I hated every second!

The problem with this vehicle is all of the curved surfaces on it and the enclosed cab with no side windows and a curved windshield. Frankly I'm just not up to this yet so I decided to just get done what I could and be satisfied. 

The end result is OK I think but its not entirely accurate and the scale seems to have creeped up slightly on all of the other Fiats that I've done. Not by much, and with a softskin put on the back you will probably not even notice... but I know, and thats bad enough!

Anyway, this is a picture of the Furgon as I aim to finish mine:

The genereal utility version of the Furgon with its soft top on.
The sculpting that I did took a similar course to the other Polski Fiat 508's that I have already done with adjustments made for the cab. I decided to do a fully enclosed cab as I would rather paint black holes instead of actually have holes in my vehicle.

Once I put the softskin on the back it should prove to be one of the easiest to cast and reproduce as there are very few awkward areas that will tear a resin mold.

This is what I managed to knock up:



Not terribly interesting but there we go...

Now onto something a whole lot more enigmatic:

The TKS-D tank destroyer

The TKS-D was a further development of the TKS tankettes that initially had led to the TKD self propelled gun. The development of this little beauty was atypical of normal armoured vehicle development as it was originally conceived as an artillery tractor designed to pull the wz.36 Bofors 37mm anti tank gun and an ammunition caisson.

The TKS-D without the top skirt armour showing its caisson at the proving grounds in Barycz


It was conceived that the actual weapon itself could be dismounted from its carriage and mounted on the vehicle itself to be put back onto its carriage when setting up for anti tank duties.

Photographic evidence suggests that whilst even towing the carriage and caisson the TKS-D was only ever used with the gun mounted and by virtue of this fact became, in point of fact, the worlds first tank destroyer.

Fording a river in 1938 and showing the cannon dismounted from its carriage and placed into the vehicle mount.

One area of massive advantage in this role was its very low silhouette which potentially made it a particularly difficult target to hit.

The TKS-D was developed from a modified TKS tankette chassis, just as the C2P artillery tractor was. There were differences however, for example in the TKS-D side clutches were used in the transmission and bigger idler wheels, set closer to the ground as extra road wheels were used in order to increase the stability of the firing platform and provide better traction.

The main designers were J. Lupuszewski and H. Lipko who worked under the auspice of R. Gundlach who completed two prototypes in 1937 using chassis TKS nr.8897 and TKS-B nr.1510, with the TKS-B chassis already having been retrofitted with new running gear.

The TKS-D's had a new extended hull, most of which was taken up with the open topped crew compartment. Each of the prototypes had differences in hull shapes with one of them having a higher circuit wall, enclosing the entire circumference of the crew compartment and that sloped inwards at the top whilst the other only had the top sloped extensions on the frontal third of the vehicle.

The 'other' TKS-D showing the all round armour skirt
The gun sight, aiming mechanisms and loading block were all positioned on the left hand side of the gun so the drivers position was changed to the right hand side of the vehicle with the space behind him being used for ammunition stowage.

Each of the prototypes was also equipped with a two wheeled ammunition caisson that carried a further 80 rounds of AT ammunition.

Climbing a bank and giving a good view of the caisson and the gun carriage sans gun!
Once the two vehicles were completed they were tested at the Army Training Centre in Modlin. By 1938 they were assigned, along with the 4 strong platoon of TKD's to the 10th Motorised Cavalry Brigade being deployed on manoeuvres in August and September 1938, then participating in the reoccupation of the native Polish Zaolzie province from the Czech republic (this, when looking under the surface is quite a dirty episode of Polish politics which was rewarded with accusation of assisting Nazi Germany in the dismemberment of the Czechoslovakian state, had Stalin mobilising the Red Army and offering to land 700 fighter planes for Czechoslovakian use in the defence of the disputed territory, which was then followed up with some seriously poor political and social practises by the Polish government in the two states that comprised the Zaolzie province essentially turning the majority native quarter of a million Polish inhabitants against its own new government).

Being displayed for King Carol II of Romania in 1938
Further clarity on the actions of the TKS-D's is sketchy at best with no photographic evidence yet surfacing but the most recent research ('Dywizjon Rozpoznawczy 10 Brygady Kawalerii 1938-1939' Eugeniusz Piotr Nowak, 1999) suggests that the TKS-D's were still present with 10BK and along with 4 truck towed wz.36 Bofors, allocated to the Reconnaissance Battalions anti tank company, furiously resisting the advance of two German Armoured Divisions through the Beskidy Mountains (I've  holidayed in the Beskides and they are covered with switchback trails that wind inbetween steep and deep valleys) with one being lost on 5th September during the fighting at Skrzydlna and the second finally falling on 9th September at Albigowa.

Modelling the TKS-D

So this little beauty may be a tiny piece of cordite packing loveliness but make no mistake this was one bitch to put together. Its so small and so intricate with an open interior that I was frequently having to re-cut things, trim them down, redesign and redo parts.

Of all the vehicles I have done, this is the one that has taken me the longest to do.

The schematics of the TKS-D that I found to work off of

Now, fortunately I just happened to have a broken True North miniatures wz.36 Bofors laying around and so I decided that I finally had a use for its barrel! I also had ordered Early War German vehicle crews from Skytrex and I thought that these would do nicely as crews (with a little tampering of course).

I already had wheels with mudguards prepared for my Fiats and thought these could do double duty as the wheels for the caisson. Finally I realised I had no track sections that I could use.

However having an over abundance of TKS' I decided to rip the track sections off of one of these to use for some home casting to provide the track sections for the other TKS-D I need to build and the TKD's.... the rest is all me baby...






... and there we have it. Another rare Polish vehicle done.

At this point I now have another one of these to build as well as two TKS models. Given all of the Half Track conversions that I have ahead of me as well as actually learning how to cast models I have to say that I may very well have bitten off more than I can chew this year so to speak.... however when has that ever stopped me eh?

You just dig in and kick on. See how far you get! :D

Fix Bayonets!!!!


Sunday, 12 February 2017

Flames of War: Modelling the Polish wz.34 Half Track truck... and more specifically the C4P Halftrack variant

The Polish wz.34 Halftrack, a home produced variant of the Polski Fiat 621L license built 2.5 tonne truck
So, even though I have made much progress sculpting and modelling my through the giant mountain of vehicles that The Black Brigade requires to field I find myself in the position that I still need to knock up some of the more prolific ones that they used, and one of these which was used in some numbers was the Polski Fiat 621L truck conversion into a halftrack; the wz.34 and its derivative; the C4P artillery tractor.

Ironically though, one of these half track models was also used by the Infantry Divisions heavy artillery batteries to tow the 155mm Howitzers so knocking up some of these ones would also see them serve double duty! Yay!

Where these babies were concerned though I am happy to say that I was aware right from the start that I wouldn't need to do a complete sculpt as the majority of the body shape was already available by using True North Miniatures Polski Fiat 621L trucks and just modifying them slightly. Simply put, I would just need to buy the vehicles, do a bit of nip and tuck, 'eh voila!'


Because I wont be selling these though I figured it would help any potential Polish players to give complete instructions on how I went about the modelling of them (You're welcome!) ;)

The evolution of the wz.34 and C4P

Poland was a major user of foreign built halftracks during the interbellum and more than any other was the Citroen Kegresse P17 and P19's designed by Adolphe Kegresse, the former chief of Tsar Nicholas II's motor fleet. On returning to France after the Russian Revolution he continued to develop the half tracked mechanisms, funded in part by the French army.

Kegresse's first completed project was a half track mechanism for the Citroen B2/10CV used for the cross Sahara desert rally of 1922/1923 followed by a journey across Africa in 1924/1925 (La Croisiere Noire)

Watching closely the Polish military determined that this travel mechanism seemed to be an ideal solution to cope with the proliferately poor roads in Poland, and even more so in the East of the country and so, after trialling the vehicle for a year opted to purchase 135 chassis' increased from an initial order of 108.

90 of these chassis were used to build the wz.28 armoured car (Ive done a blog of the three of these that I have constructed by the way) and the rest were signed off for trucks and special vehicles.

In early 1931 a contract was signed with the French who agreed to supply the Polish with a further 94 half tracked vehicles of varying designs (C6 P14, C4 P17 and C6 P19's) and these were delivered between May 1931 and December 1933 in various formats including artillery tractors, staff cars and telephone cars amongst others.

The C4 P17 carried on service the longest as an Artillery Tractor (and there is another post that I have done with regards to the Citroen-Kegresse Half tracks that were still in use in 1939.

The Citroen-Kegresse variants and the ensuing wz.34 designs. Image take from PIBWL (the 1939 Polish military vehicle holy grail!)
The Poles however, went on to develop the wz.34 and C4P from this design.

The Wz.34 Halftrack

Between the two world wars half tracked vehicles  became common currency in a lot of the worlds armed forces as they offered good (or better) off-road traction and mobility at a good relative cost. Look no further than the German Hanomag SdKfz 251 to see the evidence of this in action.

The Polski Fiat 621L 2.5t truck was produced under license in Poland from 1932. The half track version was designed in 1934 by the Armoured Forces Technical Research Bureau (BBT BP) based in Warsaw. The design itself was not a complicated one and was designed primarily to utilise many of the existing truck components including the chassis and engine block. Many of the other components were strengthened or modified including the gearbox which was adapted to better suit off-road movements.



The most obvious adjustment was in actually forming the half tracked vehicle by adding a rear axle tracked mechanism, which originated from the French supplied Citroen-Kegresse P14/17/19 halftracks and Vickers E tank suspension assemblies and modified slightly to derive a Polish version which suited the specs provided to the designers.

A prototype series of the wz.34 was built in 1935 whilst the series production started running in 1936 in PZInz (Panstwowe Zaklady Inzynieryine - State Engineering Works) in Warsaw.



By 1939 some 400 or so wz.34 halftracks had been produced in all versions. At least 80 of them were produced as Artillery Tractors designated C4P whilst many of the others became engineering vehicles and Battlefield Ambulance vehicles whilst the majority of them were designated for troop movements such as used by the 10th Motorised Cavalry Brigades Terrain battalions which were equipped with the wz.34 instead of the Polski Fiat 621L truck.

Overall the wz.34 design was quite a successful one and saw a lot of active service in all areas, the main drawbacks of the design resting primarily with the truck engine which consumed far too much fuel and was underpowered for the jobs it was being asked to do!

The most prolific version of the wz.34 were the ones used as all terrain transports, recovery & repair vehicles, field workshops, armaments workshops, trailer tractors and such like in different units such as engineers and railway engineers.

A wz.34 Mobile Repair Workshop halftrack
Two of these halftracks were allocated to each Vickers E or 7TP tank company as repair vehicles, or even more. In the case of the 2nd Light Tank Battalion in 1939 they actually had 12 on strength, whilst in the 21st Tank Battalion (with the R-35's) there were 3. Two of these halftracks were also provided to each armoured train as a repair patrol and were usually carried on the flat cars.

Wz.34's were also used as troop carriers by the 10th Motorised Cavalry Brigade (10BK) from the summer of 1937. The two regiments in the brigade each had 12 vehicles allocated to them for terrain movement in place of the trucks and were used during the Black Brigades deployment to Zaolzie over the Czech border during the Polish reoccupation of this territory.
However, nothing has yet come to light of them being used in 1939, with no photographic evidence, no written references and none being recorded as being handed over to Hungarian authorities once the Black Brigade crossed the border. However this does not mean that they were not used, only that it is unlikely. The likeliest of reasons would be that the operational reviews of the vehicles after the 1938 field exercises and the Zaolzie deployment was that they simply weren't good enough for what they were required for and were therefore retired in favour of the Praga RV trucks which did sterling service in September 1939.

A wz.34 Ambulance Halftrack
Another uses of the wz.34 (which I wont be modelling by the way in case you were interested) were as field ambulances with the Polish Red Cross, which weren't actually a part of the Polish field armies but were an independent organisation working alongside the army, enabling the army to save budgets.

The C4P Artillery Tractor

From late 1936 C4P tractors were issued to the 1st Motorised Artillery Regiment (1. Pulk Artylerii Motorowej - 1.Pamot) replacing the older Citroen-Kegresse P14 and P17 halftracked tractors that they had had for the last couple of years. Not enough C4P's were able to be produced before the outbreak of war  to totally replace all of the existing French tractors meaning there were stocks of these still used in the war.



The 1.Pamot was a peacetime asset that was garrisoned in the town of Stryj, now located across the Ukrainian border. According to a TO&E of 1938 the 1.Pamot comprised a Light Artillery Battalion of 2 batteries of 75mm's Field Guns and 1 battery of 100mm howitzers, and a Heavy Artillery Battalion of 2 batteries of 120mm Field Guns.

Until 1935 the 105mm wz.23 artillery pieces and the 155mm wz.17 Howitzers were also constituent parts of the Motorised Artillery.

During the mobilisation of the summer of 1939 the 1.Pamot was able to create three Motorised Artillery Battalions (dywizjon artylerii motorwej - dam). Two of them were light artillery battalions that were each assigned to the two motorised brigades that Poland was able to field. Each light battalion had two four gun batteries.

The 2.dam was assigned to the Warsaw Armoured Motorised Brigade and was equipped with two batteries of 4x75mm field guns although it is likely that the 2.dam was equipped with the older Citroen-Kegresse halftracks.

The 16.dam was assigned to the 10th Motorised Cavalry Brigade and was equipped with one battery of 4x 75mm field guns and one battery of 4x 100mm howitzers.

The 16.dam was provided with 18 C4P's that were used for towing the field guns and howitzers. The guns were towed along with their caissons, whilst other tractors were designated to tow ammunition trailers. All guns and equipment were fitted with pneumatic tyres.

One of 6.dam's C4P's abandoned in September 1939
The third mobilised motorised artillery unit drawn by halftracks was the 6.dam which was signed off to Army Lodz. This was a heavy artillery asset that fielded three 4 gun batteries of the older 120mm Schnieder wz.1878/09/31's. This battalion was fighting from September 13th in the Zamosc area and was equipped with tractors that had the short platforms and open backs.

Modelling Polish Halftracks of September 1939

Anybody who plays anything motorised for Poland 1939 is going to face the problem that there is next to nobody out there who manufactures the wz.34 and the only ones that do, do it badly (well theres a shock!)

There are perhaps two saving grace here however, and that is firstly the fact that almost all of the half tracks were variants of the wz.34 and secondly there is one manufacturer who produces the Polski Fiat 621L truck at a quality that is good enough for our uses, and that of course is True North Miniatures owned by Andy at Old Glory UK.

These trucks from True North take care of anything you need to do with the body other than the dicing and slicing which I will explain about shortly... but what about the track sections?

Well the company I buy my Citroen Kegresse P19 Artillery tractors off (QRF Miniatures) were happily willing to sell me a load of extra track sections and with a slight adjustment these served adequately as the wz.34 track sections.

Wz.34 Terrain Transport

Of all the half tracked vehicles used by Poland in 1939 this one was the most prolific, and thankfully by far, the easiest to produce!



For this model all I did was simply take the True North Miniatures Fiat 621 truck and remove the back wheels and use my Razor Saw to slice off the spare wheel that is slung under the very back of the chassis frame.

One of the double back wheels is cut in half with the outer half being used to mount on the left side of the cab with a small rectangle of styrene mounted on the top of the hub as a retainer.



The QRF Miniatures Citroen Kegresse track sections each had the front two bogie wheels cut out wit the rough edges sanded back and the tracks themselves reworked so they looked tight on the bottom but loose on top. A length of 1.5mm brass rod played the part of axle and the unit as a whole was then glued to the bottom of the truck chassis



Once the back of the vehicles was glued on two small curved lengths of brass strip were used to build new fenders which link the vehicle cab mounting to the flat bed on the back of the vehicle.

Oh yeah, I also opt to close in the cab of the vehicle by using really thin styrene sheets. I would rather paint windows that have empty spaces with no glass...

Eh voila! The first of many half tracked vehicles completed.

Early model C4P artillery tractors

Now, I'm not convinced that any of these tractors were still in existence when the Nazi's invaded as I have never seen any photographic evidence. I have a suspicion that at the very least all of them had been upgraded by the time the war started and supplied with closed cabs. However when all is said and done, these are a funky little option that I also cant find any documentation stating that these were no longer in use and as such I decided that having four of them would be a good little addition to a Polish Army.

An early model C4P artillery tractor with the canvas roof over the rear crew compartment and the forward open cab area

These ones are however, the most complex of all of the Polish half tracked vehicles to produce.

As with all other halftracked models the rear wheels are removed, although with the early model C4P the rear chassis under slung wheel was left in place.

The chassis arms were shortened so that the overall length of the vehicle was shortened to the appropriate length.

The track sections were prepared as with the wz.34 and it is here that everything changes!

In place of the cab an engine hood extension was built using three deep rectangles of 1mm styrene sheet which was then sculpted to provide a straight sided and curved top with the application of Magic Sculpt epoxy resin which was then sanded back.


The double seat was built using stacked styrene topped with sculpted epoxy resin with the curved protective bodywork which surrounds the seating provided by a length of 1mm styrene that had been curved into shape over a heating source and then trimmed down to size until perfect.

Once complete the drivers compartment was test fitted with miniatures designed for driving vehicles just to make sure that no further adjustments were needed.



The rear compartment had to have the rear 1/3 cut off of it, and I lined this up with one of the vertical metal bands so that this could do double duty as the rear cab end posts. Once the horizontal rear third was removed a longitudinal section three wooden planks wide also needed to be removed and this was done using my razor saw with the two remaining halves pinned back together with a styrene bench being created and glued into place against the back wall.

Four post holes were then drilled into the corners of the rear cab with brass rod filling the position of the lower half of the posts that provided the frame for the canvas cover of the forward and rear cabs.


The bottom of this rear cab has to be sanded down so that the lift of the body above the track sections is not so pronounced that the canvas hood looks like a high ceilinged Victorian house! Once this is done two lengths of brass strip are cut and shaped to represent the fenders that run the full length of the track sections with a sharply curved front end that joins to the forward cab area and the rear shallower sloped section that fits alongside the vehicle tow mount. These are both glued to the bottom of the shorter and narrower rear cab area.

The frontal window frame and the rear vehicle tow attachment were made very simply out of shaped styrene carefully cut to shape and glued to the vehicle with the front window frame also being epoxy resined into place and then shaped and sanded.

Finally, this tractor had to have a canvas roof built for it using the same method I used for the other canvas backs. A styrene fbox was created which had brass rod fitted to it in the shape of the actual canvas frame on the real vehicle and then epoxy resin is applied, shaped, sculpted and sanded to give the final version of the canvas roof... and there we have it! Only three more of these to do!

Late model C4P Artillery Tractor (Short Chassis)

It is this one that I believe was likely to be the most prolific of the half tracked tractors that the Poles used in 1939. I also believe that it is these that the early model C4P artillery tractors were upgraded to and are simply the same vehicle but with an enclosed cab.

A late model C4P showing its full cab and with its 100mm howitzer still limbered up. A great study of Polish camouflage.
This is a relatively simple conversion from the Fiat 621 truck to the finished halftrack.

The chassis frame is shortened as with the above version, along with the underslung rear wheel being removed with razor saw and the rear crew compartment is shortened and made narrower to the same directions as given above.


The track sections are prepared as before as are the track fenders which are identical. This time however one of the rear wheels is sliced in half with the front half mounted alongside the left door as with the wz.34 half track conversion.


The rear crew compartment has two brass rods bent to the shape of the canvas roof frame and fitted into the four drilled out post holes.

..and finally the frontal cab has all of its windows sealed using styrene sheets and the rear vehicle tow asset is constructed with styrene and glued onto the back of the chassis on its own mounting.

Boom! Done! (and yes, for those of you who are observant you will spot that I had actually forgotten to adjust the Citroen Kegresse track sections on this one! 6 weeks sculpting and modelling Polish vehicles does strange things to a mans head!)

Late Model C4P Artillery Tractor with shell storage cases

There is one final version of the C4P to build that is a little more mysterious than the others. With the previous three versions of the wz.34 and C4P there is definitive and available photographic evidence that the vehicle actually existed.

With this one however I cannot find a single photograph anywhere and in fact, other than images provided by other model manufacturers I can only find a single image plate of it:

Late production C4P artillery tractor with enclosed cab and flat bed storage boxes
So this one is built just as with the one before except that the chassis frame isnt shortened and the rear flat bed is not shortened except to cut the rear wall away. The rear third of the flat bed is converted into two separate boxes using styrene sheeting with benches constructed and placed on the inner side walls of the rear crew compartment as shown below.


Truth be told I actually cocked up the measurements on the rear section on this one as the boxes shoujld be bigger than they are so I am intending, on the other three of these that I will need to build I think I will shorten the rear chassis frame and flat bed and then the dimensions of the two boxes mounted on the end of the rear compartment will have dimensions closer to the real thing.



So there we have it. Four new half tracks for my Polish army.

Anybody else who wants to play the Black Brigade (or the Warsaw Armoured Motorised Brigade) will have to, at some point make an effort to get a hold of some half tracks and the beauty behind these is that you don't need to sculpt, convert and cast your own. You simply need to buy a collection of Fiat 621 trucks from True North Miniatures, get a hold of some track sections and put some effort in with the Styrene and there you go, some of your very own half tracks!

Now, after 6 weeks of sculpting Polish vehicles I'm really starting to miss my brushes so I am going to take a break two vehicles short (the Polski Fiat 508 III Furgon and the TKS-D) of everything I need to do and head off and paint some PHR for Dropzone Commander for a bit!

Fix Bayonets bitches!