Scale Model Shop

**Guest** · 01 July 2010, 14:37

Is this going to be a scratch build or do you have a kit lined up? Still thing you should sing the song though and post that as well lol

**Guest** · 01 July 2010, 15:54

Originally posted by \

Is this going to be a scratch build or do you have a kit lined up?

As said at the first paragraph of the article, it's a polyester resin model by White Tower Models.

**Guest** · 01 July 2010, 15:57

Since I had already brought myself into 1/35 “troubles”, I got the FDCV scale model directly from White Tower Models company, based in Thessaloniki, Greece. Mr. Christos Simitsis, who is the White Tower Models founder, produced some polyester resin scale model kits such as…

1/35 scale Mistral A/A missile launching base,
1/35 scale FDCV - Fire Direction Center Vehicle,
1/35 scale Mercedes Benz 240GD G-wagen 4x4 vehicle,
1/35 scale conversion kits for Leopard 1 A4/GR1/A5/V,
1/35 scale Leonidas I & II IFV - Infantry Fighting Vehicle,

...and other scale products since early 1990ies. Today, almost 20 years after first public release of the 1/35 scale FDCV model, the White Tower Models continues to product very few kits & sell selectively mostly to friends. Mr. Christos Simitsis, named his White Tower Models company after the White Tower, which is the trade mark monument and museum, located on the waterfront of the city of Thessaloniki, Greece. Some pictures of mediaeval White Tower monument, as seen behind a statue of King Philip II, father of Alexander the Great - the most famous Greek ever.

The 1/35 scale FDCV kit I got directly from White Tower Models company, was carefully packaged.

The assembly instructions contained in the kit is actually a simple B&W printed A3 size sheet, folded to form a 4 page guide describes the building stages and also providing some B&W pictures of the real FDCV as well.

**Guest** · 01 July 2010, 16:01

Sorry Nick, I didn't read the title part very well at all did I. The good news is that I have an eye test booked for next Tuesday morning...........:nonono:

**Guest** · 01 July 2010, 16:02

The polyester resin pieces were carefully placed into sealed transparent bags. Careful inspection followed to spot any possible defects, cracks, gaps, etc. As expected, everything was normal.

Unable to resist the temptation to compare the small details of the White Tower Models polyester resin kit with the Italeri’s M-109 kit. In the first picture the White Tower Models polyester resin kit (light green colored), and the second picture is the 1990ies era Italeri's M-109 kit (dark green colored).

In similar way, I placed side by side and compare the tracking wheels. In the following picture, the left wheel (light green colored) is the White Tower Models polyester resin kit, and the right wheel (dark green colored) is from the Italeri’s M-109 kit.

The following pieces are very fragile, so I carefully placed them on foam and stored them, till using on kit.

The use of polyester resin, makes the kit suitable for advanced modelers - not for rookies. Considering that I have zero experience on tracked AFV / IFV / SPG scale models, the chances to complete successfully this project are… less than few! For this reason, I keep the right tool next to me and if something goes wrong, or polyester resin give me hard time, I decided to test the fast-moving hammer impact effects, onto polyester resin made scale model.

**Guest** · 02 July 2010, 01:57

CHAPTER I - Polyester resin preparation & cleaning

Since I had to accept that this stupid bet I lost, could compare like Hell become frozen, I should keep my promise before El Diablo himself got aware and switch on the heaters again. I really hate it. I even tried to avoid it by all means, I used every possible and impossible excuse, but the answer was “NO”! In short, I’m in deep sh!t and I have to complete building process. Pacta sunt servanda…

While I was inspecting the resin pieces, I noticed some marks on the surface of polyester, which looked like raised stains as defects in the casting mold. Fortunately my scale modeling mentors trained me well and I was prepared for such situations. Obviously, these marks were the remains of the liquid chemical used in the preparation of polyester resin and it's not unusual in such kits. Keeping in mind that the polyester resin chemical composition is such that can be cleaned by nitrocellulose lacquer thinner, without harming the structure, I decided to use nitrocellulose lacquer thinner to clean up locally. The nitrocellulose lacquer thinner cleaning method described below and shown in the following pictures, should never be applied on plastic injection molded kits, because the results would be disastrous and your model will become like a chewed gum.

My good friend Demitris “Jagdpanther” Pravinos, who is a WWII German armoured vehicles specialist and dedicated scale modeller, sent me few hundreds cups (actually spray canister caps) he found and looked ideal to use them for mixing colours, modelling putty etc. Few drops of nitrocellulose lacquer thinner were just enough. Using a cotton swab, I spread the nitrocellulose lacquer thinner on target stain, rubbed and the chemical were magically dissolved, leaving completely intact the surface of polyester resin and the kit detail. The result can be noticed into following pictures. Same technique was applied to other parts of the kit where chemical residues observed treatment of polyester resin.

Keep in mind that use of preventive measures, such as in disposable surgical gloves from latex, masks with similar filters to protect against possible fumes, etc. is always recommended during handling epoxy resins materials or resin powder contact. These nasty materials are not too very friendly to our health. Taking care of our health is a serious factor that should not be left to chance, not to challenge the lungs or the finger skin! I personally recommend to wear a coverall suit to protect your clothes and keep polyester or epoxy resin dust ‘n’ chips away. Some people might say “too much”, but nobody wants to convey polyester or epoxy resin dust ‘n’ chips and other dangerous carcinogenic filings found on our modelling bench in the family’s living room and into the arms of loved ones.

Few small holes were spotted on the polyester resin kit, obviously due to bubbles created during the casting process. Fortunately, these small spots were observed only on the inside part of the polyester resin kit and these holes were not big enough to reach the outer side. However, because I didn’t want to risk any future unpleasant surprises, I thought as a nice idea to fill the area with epoxy filler. Keep in mind, that few months or years after casting, the polyester resin becomes fully polymerized and gets so hardened, that it’s easy to break like a glass. The possibility that the slightest vibration during scale model’s transport could create a crack starting from the point inside the bubble and leading to the outer surface of the model, is always present.

These small holes were filled with epoxy cream. I prefer to use epoxy putty (or polyester filler with fiberglass grains for special purposes) instead of normal scale modeling putty, to close gaps or build new items, because:

It becomes solid rock within only few minutes or seconds,
It does not shrink and does not crack after months or years,
It can be poured to any shape that you want but you need to work fast because as soon as you mix it with catalyst cream approx 5%, you have limited time before becoming solid rock,
Additional layers of epoxy or polyester filler can also build up,
It can be sawed, sanded, drilled etc and is compatible with any type of scale modelling glue & any type of primer or enamel / acrylic paint with no problem at all,
It can be purchased at any good crafts store into 250ml, 500ml, 1lt (comes with a tube of catalyst hardener) or bigger canisters and if you can't find it, fear not and try your local decent hardware store and finally...
It is cheaper than dirt - estimated prices are £3 to £10 depending the canister size, the quality, if contains fiberglass grains for maximum strength etc.

Keep in mind that the chemical reaction after mixing the filler with the catalyst hardener, produces some heat that possibly effect on thin plastic parts, so test it first before try it on your scale model. I don’t think that the produced heat is more than Fahrenheit 110°, but better watch out.

**Guest** · 02 July 2010, 16:39

CHAPTER II - Do you feel lucky?

Since I had the official technical & maintenance manual of the real FDCV - Fire Direction Center Vehicle in hands, I thought that it would be a good idea to open panels, hatches, doors etc and try to scratchbuild full interior, showing the crew working benches, the "Pythagoras" FPU - Fire Control Unit computers, the driver's compartment, both front & left side APU - Auxiliary Power Unit hatches, the engine & batteries compartments etc.

Obviously, the idea to open hatches and scratchbuild full interior was a huge mistake. Unfortunately, because of my enthusiasm, I had already begun to rip the towing cable which of course was perfectly imprinted, but my modeling knife had an irresistible desire to cut-cut-cut!. In fact, I had already built from scratch a towing new cable, using telephone wire.

Yeah, I admit, that I regret my previous choice as soon as the blade started to cut and remove the polyester. I had already crossed the "red thin line" that demarcates the controlled risk - I was playing with fire! I felt like gambling on Blackjack and asking the dealer to hit cards, while I already had a “21” in my hand!

At this exact moment, I recovered and remember my childhood hero San Francisco Police Department Inspector "Dirty" Harry Callahan asking (click HERE): "...considering that this is a polyester resin rare to find model that does not forgive mistakes and requires special attention, you got to ask yourself: 'do I feel lucky?'..."

Do you feel lucky? Well, do ya?

If this was an aircraft or helicopter scale model, hell yeah, I would 100% try to scratch. But just because I am an AFV rookie and considering that polyester resin does not forgive mistakes and this FDCV - Fire Direction Center Vehicle scale model is quite difficult to find & buy again if something goes wrong, I chose something with low risk, such as “straight from the box” building. Maybe some of you might expecting a project from scratch with full interior and opened hatches, but it should be postponed for another time - perhaps after 30 years, when I am planning to build an AFV scale model again.

...thanks to Uncle Harry, I stopped cutting before ruining this beautiful polyester scale model.

**Guest** · 02 July 2010, 16:40

CHAPTER III - Chassis building & structure supporting

As long I decide to build the kit straight from the box, without interior details and keeping all hatches closed, I placed a styrene plastic sheet to keep driver's hatch isolated. The reason will be explained later.

The HPX, is one of the most durable adhesive tape that can be found on the local market. It is vinyl reinforced multi-purpose pressure sensitive tape with a soft and flexible shell and pressure sensitive adhesive. It is generally silver or black in color but many other colors have recently become available. With a standard width of 50mm (approx 2 inches) & 0.30mm thickness, water resistant & withstand temperature ranges from Fahrenheit -40° to Fahrenheit 203° is ideal for special purposes. It is constructed from a rubber-based adhesive to help the tape resist water and a fabric backing to add strength. Keep in mind that US Military issued this hard duty adhesive tape to their personnel who keep it in their pack and use it in numerous cases, such as repairing scratches, temporarily taping holes on aircrafts or helicopters fuselage, ammo canisters sealing, repairing military equipment (including firearms) quickly etc. Click HERE for aircraft repair with adhesive tape example. In military circles, this variant is known as "gun-tape", typically olive-green, and also known for its resistance to oils and greases. It is also called "Riggers Tape", "Hurricane Tape", or "100-mph tape" - a name that comes from the use of a specific variety of duct tape that was supposed to hold up to 100 mph winds. Another version attributes this to the fact that soldiers often refer to something that exceeds expectations as "High Speed". The HEX tape is commercially sold as high-strength adhesive tape for sealing tire tubes aquifers.

Before trying to connect FDCV’s main chassis, I stretched tape inside the two halves. As it is known, polyester loses its elasticity and becomes harder, several months or years after casting and vibrations could cause cracking. The polyester made models do not have the durability of plastic because the different chemical composition and molecular bonds of each material. Over time, polyester behaves like glass, although it has toughness, but any hard vibration could cause crack or even worse shattering. Placing HPX durable adhesive tape inside, would hold the spread of a possible crack in the future, provide the opportunity to fix and save the scale model. In all other cases, the polyester fragments would be lost. Placing HPX durable adhesive tape inside, is the first of few precautionary measures taken for the integrity of the material. The next and most important precautionary measure, will be described into following paragraphs.

**Guest** · 02 July 2010, 16:42

To be honest, I thought that when the time comes to connect the chassis two halves, I would face plenty of problems. Let’s not forget that this specific kit is made of polyester resin, rather than an injection molded Japanese plastic with excellent quality and factory mass production of tens of thousands of kits. This is actually a handmade kit, molded in silicon. After carefully cleaned from the polyester casting excess in contact points between the chassis two halves, I tried repeatedly to contact each other to be sure that I will not face any unpleasant surprises after applying super glue. To make the job easier, the chassis two halves dipped in hot water for 1-2 minutes to obtain polyester flexibility (which lasted for the few critical minutes) and to assist my effort to buckle one part into the other. That’s why the adhesive tape used and described previously, was the HPX product with high temperature & water resistance - if I would try a simple cheap tape, it would just come off as soon as the polyester kit parts immersed into hot water. Same elasticity effect on polyester could be achieved using a hair dryer and guiding hot air on selected spots. When the two halves buckled together, I dropped cyanoacrylate glue on all four corners and later secured the construction stability by applying two components super glue, across the chassis two halves contact line, using a wooden toothpick.

I am not used to fill gaps with simple modelling putty, since I prefer a two-component epoxy or polyester putty. As mentioned into previous paragraphs, I mostly prefer to use epoxy putty (or polyester filler with fiberglass grains for special purposes) instead of normal scale modeling putty, to close gaps or build new items.

Just because this is a polyester kit and the material does not get affected and does not get damaged by the nitrocellulose lacquer thinner, I thought nice idea to follow something different. I tried spreading Humbrol simple modelling putty on the gap, and applied generous amounts of nitrocellulose lacquer thinner on Humbrol putty, to get it soften, turn it into semi-liquid form and smoothly spread it across the chassis two halves contact line.

Finally, only few drops of nitrocellulose lacquer thinner on small amount of Humbrol modelling putty, was enough to create a liquid solution to spread with brush across the chassis two halves contact line.

**Guest** · 02 July 2010, 16:46

As noted before, polyester loses its elasticity over time and the slightest shock, bang or hard vibration during model transporting may cause a crack. To reduce the danger of such an unfortunate situation and as a part of precautionary measures to strengthen the structure of the polyester model, I decided it would be nice to fill the internal model with the material that should be:

Solid and able to occupy all the available volume inside the model, supporting internally the walls of the polyester model,
As light as possible to avoid model’s total weight increasing that could strain the wheel polyester arms,
Hard, but not completely rigid, that can absorb vibrations & shocks and able to transmit vibrations soflty, throughout model’s mass and not on a single point.

This material is called polyurethane foam. It is a unique industrial material which has excellent physical, mechanical and environmental properties and is mainly used as insulation material. It offers high abrasion resistance, tensile stress, impact resistance etc. The fact that the polyurethane foam material can be easily cut, sawed, sanded, drilled etc and is compatible with most types of scale modelling glue & any type of primer or enamel / acrylic paint with no problem at all, makes it a good choice for many scale modelling applications, as for example in diorama building.

I got one polyurethane foam spray canister with the trigger & tube to inject the material, from my local hardware store. Because cleaning the plastic injecting tube would be quite difficult when the polyurethane foam begins to be polymerized after contact with air, I cut the plastic pipe and replaced it with a straw which I threw out after each use.

Before channelling the polyurethane foam inside scale model, a preparation should be applied to achieve best possible results and to avoid any unpleasant surprises. I chose as the point from which will channel the polyurethane foam, the only opened hatch - the crew commander’s hatch. This is why I closed driver’s hatch, not to let polyurethane foam escape from there. Masking tape 50mm width, applied to cover the upper surface of the FDCV and protect it from possible polyurethane foam overflow.

**Guest** · 02 July 2010, 16:47

Injecting polyurethane foam needs full attention and should not exaggerate the filling quantity because it takes time that can reach up to 2 hours from the application of the material to swell and solidify. According to the instructions on the spray canister, the best results are achieved when sprayed successive small amounts of foam and wait to swell and partially occupy all the available volume inside the model. Considering that the expanding polyurethane can multiply the original foam volume up to 4 times, it would be very appropriate to inject small quantities, allow time to swell and since we are confident that it has solidified and will not change over its volume, to continue the process with successive small amounts of foam. To conclude the process, I began to inject small amounts of polyurethane foam, first in the more distant spots, such as the front left or front right under the engine’s compartment etc. After the 2-3 small doses of injectable foam placed in appropriate locations, I wait enough time (over 6 hours) to swell smooth polyurethane and cover the internal volume without endangering the vessel to deform or break (worst scenario) from inside out, under high pressure on walls. Then, I added 1-2 more doses of polyurethane foam to the rear part, being careful to inject small amounts and let the material to expand slowly or escape if necessary, from the crew commander’s hatch.

As you can see into following picture, it seems I was lucky, because while material expanding, the polyurethane foam managed to find a way out and despite a little leaking from the driver's hatch. Although, the contact with air was quick and material became solid before escaping to the outside, covering the panel lines and kit details.

After 3-4 small doses of polyurethane foam, with several hours stall time between injections, the material properly inflated and occupied all the available volume of the scale model’s interior. Because of wrong calculations during last injection, polyurethane foam escaped from the nearest (and only) way out - the crew commander’s hatch. Fortunately, this was the last dose and the excess was removed quickly with a spatula, while having established such a case, the protective coating of the outer surface with masking tape, proved thoughtful choice.

After the last dose of polyurethane foam hardened, the excess material overflow from the driver's and crew commander’s hatches were removed carefully, using No 11 blade on modeling knife.

With the method described in the previous paragraphs, I achieved to:

Fill the interior of the FDCV scale model with foam that can absorb vibrations and distribute throughout the mass of polyester,
Apply a hard duty adhesive tape across the inner surface, to hold united the shattered parts of polyester if ever broken.

The above protection measures, are not necessary (and possibly not recommended) for use on 99% of commercial kits marketed. The polyester material specificity however and the possible danger to break after few months or years, after losing its elasticity and becoming harder and inflexible (and therefore fragile), enforce these protecting measures to ensure better luck VS possible shock hits & hard vibrations during scale model transport.

**Guest** · 02 July 2010, 16:48

CHAPTER IV - Dalton brothers in chains

Goscinny & Morris who both created the “The Judge” story (based on real Judge Phantly Roy Bean, Jr life) into Lucky Luke comic, claim that bicycles & Dalton brothers, should work only in chains. While building this scale model, I found that AFVs, also use chains - yeah, I am an aircraft scale modeller.

I have to admit that when I opened the model package and saw the tracks, I was disappointed - wrongly as it proved later! Yes, although the excess of polyester to be removed (normal and expected for such a polyester hand made kit). Being an AFV scale modelling rookie, I was afraid that I might accidentally break the track teeth in my attempt to remove excess polyester material or might damage the detail of the tracks.

Nevertheless, the two single-piece polyester tracks cleaning, proved very easy. Using new No 11 blade on my knife, I tried pure and decisive cuts on track, along the teeth profile perimeter. Just to be sure that I wouldn’t accidentally remove “something” that would have seemed odd, I took the technical manual in hand and studied the chain close-up detailed diagrams, in order to understand how it is on real FDCV - after all, I have almost zero experience on AFVs.

Using an old toothbrush, I carefully removed the excess casting polyester, previously cut with the blade. I found, that although the track teeth look very fragile, ultimately proved quite durable. Finally, I cleaned by removing small amounts of polyester, using a paper nail file which could easily enter between track teeth.

The polyester used by the White Tower Models for casting, is a material which acquires hardness after several months or even years. The specificity of polyester, not only should not discourage the modellers, but use the material’s natural properties, to his advantage. Let us note that when the polyester parts sunk in hot water, even though they have produced some years ago, they get flexible for a few minutes. This time period is enough to connect the hard or marginal contact parts. As mentioned before, same technique with hot water used to buckle the two half FDCV hull shells, because I did not want to take chances and push the polyester pieces one against the other, risking a possible crack. In the following pictures, you can observe the single-piece polyester track elasticity and tolerances that can be purchased for a few minutes with proper preparation.

**Guest** · 03 July 2010, 07:35

With the FDCV scale model hull closed and the track chains cleaned by the polyester excess, I tried water sanding to ensure that connecting lines would disappear. The track chains were also slightly sanded on selected points, to get all the track teeth on the exact same level. When I was satisfied, I spray a primer light layer to prepare for painting and to highlight any deficiencies that had escaped my attention.

As shown in the photo above, I use two different primer products for preparation of scale models before painting, depending on each case.

The first is the Hycote acrylic primer. Available in 2-3 different colours, shades of grey (for general use paint) and black (primer before painting with metallic paints Alclad II) and textures in matte or glossy. The price cost aprox 7 euros in local Greek market and spray canister contains 400 ml. IMHO, the Hycote primer’s main advantage, is that the chemical composition is such that it leaves the feeling that can be applied on model without covering details. It is very fine, it dries within minutes, but it’s rare to find.
The second is the Humbrol acrylic primer. If I am not mistaken, it is available in 2-3 different colours, shades of grey (for general use paint) and black (primer before painting with metallic paints Alclad II). The price is aprox 6 euros in local Greek market and spray and the canister contains 150 ml. While using, I noticed that the Humbrol primer is sprayed under higher pressure propellant, and this effect was observed in different spray canisters. When dry, leaves a sense of rough surface on the model, perhaps a bit more than I prefer, but I guess it’s perfect when applying primer on AFVs to be given a sense of cast metal. Humbrol primer is a good choice for general purpose primer, but I would prefer Hycote for fine results, without any spray paint grains.

Finally, regarding the price / quantity matter, the Hycote primer costs 7 euros in local Greek market for a 400 ml canister (1.75 euro per 100 ml), while the Humbrol product costs 6 euros in local Greek market for a 150 ml canister (4 euro per 100 ml).

**Guest** · 03 July 2010, 07:36

For only 12 euros, I bought a new SkyTronic minitool product which operates from 0V to 12V voltage and contains 60 different parts including drills from 0.4mm to 1.5mm diameter, cutting discs, abrasive brushes, etc. According to the manual, it spins up to 16 000 rpm and is compatible with various calibers shaft head. The only modification I did, was to remove the factory cable and install spiral cable (which I find more practical) that I connected with the 0-12V voltage dimmer adapter on my workbench.

I cut the track wheels from the polyester tree and sand each one of them, by using the high speed spinning minitool. As soon as all the track wheels were trimmed as required, they were placed on exact position.

Scale Model Shop

1/35 scale FDCV - Fire Direction Center Vehicle Hellenic Army

1/35 scale FDCV - Fire Direction Center Vehicle Hellenic Army

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