ARTICLES on this page:

♦ SCRATCH-BUILDING – A discussion of building models or props without using commercially made kits.

CHOOSING THE RIGHT ADHESIVE – A guide to modern model building adhesives.  (Scroll down)

           

 


SCRATCH BUILDING

VIDEO: Blaster Rifle Mk-IV Part-2. How to build a prop from scratch.   

To see how the finished model works, see BLASTER RIFLE Mk-IV in the PROPS section.

Scratch-building may be becoming a lost art due to the increasing number of well detailed model kits becoming available in all categories (cars, trucks, ships, boats, aircraft, tanks & other military vehicles, etc.).  However, there are still model builders who enjoy the challenge of building a model without using a commercially manufactured kit. You might be amazed at the work some of these modelers produce. In this month’s issue of the International Plastic Modelers Journal (Las Vegas competition issue – Feb / Mar 2022) there were several amazing jets and helicopters that modelers had built from scratch – each one as accurate and well detailed as any kit I’ve ever seen.

WHAT IS SCRATCH BUILDING?  In simple terms, ‘scratch building’ is the process of building a model or a prop or other replica without using a commercially produced kit. Essentially, this means that you not only have to assemble the model, you have to make the parts yourself.  Depending on what it is you’re scratch building a model of, this might mean having to make all the parts yourself. In some cases, however, you can ‘cheat’. It is perfectly acceptable to use individual parts from one or more commercial kits to provide fine details or small sections of your scratch built model. In the case of building cars, trucks or other vehicles, things like tires, engines, surface details, field tools, and other precision formed parts can be adapted to complete your scratch project. Professional model makers, like those who work for movie studios, do this all the time. A great example of this are the Star Destroyer starships seen in the Star Wars movies. The ships seen onscreen were ‘practical’ models and were designed and built from scratch. However, to save time and the cost of molding or vacuforming hundreds of small detailing parts, the surface details of the Star Destroyers were taken from numerous plastic scale model ship kits. A particularly clear example of this detailing process are the twin ‘radar domes’ atop the Star Destroyers’ bridge block. These days, you may not have to ‘sacrifice’ parts from a complete kit to get the detailing bits you need. There are an ever increasing number of ‘after market’ kits available – these are cast resin, machined metal, plastic, or photo-etched sets of parts made to enhance the scale-accuracy or level of detailing on a specific commercial model kit. You might be able to find the extra parts you need in the ‘after market’ market,

WHY SCRATCH BUILD A MODEL?  There are several good reasons for scratch building. The most basic of these is that you want to build a model of something for which there are no commercial model kits. Perhaps there are kits for what you want to build, but you don’t like the detailing, or maybe the scale is too big or too small for your taste. Another good reason for scratch building is simply to challenge and expand your own modeling skills. Scratch building involves a certain amount of creative thinking which can translate into a problem solving skill that may come in handy when building kits.

HOW DO I GO ABOUT SCRATCH BUILDING A MODEL?  Regardless of what you want to build (a car, truck, aircraft, spaceship, tank, prop / replica…) and what scale you want your model to be there are several distinct steps to the scratch building process:

STEP-1. Decide what it is you want to build.  You can build anything you want, cars, aircraft, spaceships, prop replicas and so on. This requires a combination of inspiration and imagination. Inspiration can come from movies, TV shows, books, even model kits you’ve seen in your local hobby shop. In the case of my Blaster Rifle Mk-IV, the inspiration was the rifle props used in the classic sci-fi movie, Forbidden Planet. The imagination element involves looking ahead and deciding how you might execute your scratch project. It’s really a matter of evaluating a few key details – what tools you have available, what materials  you have on hand, what tools or materials can you afford to buy for the project you have in mind, and do you have the modeling skills needed for your project.  Don’t let your skill level stand in the way of starting a scratch building project – like everything else in life, practice and experience have to be acquired over time. You have to take a first step and start somewhere. Just make your first scratch project something relatively simple.

STEP-2.  Design your project. Don’t be afraid to put some time and effort into laying out how your scratch project should proceed. Make one or more simple drawings / sketches of the model you want to produce. The drawings don’t have to be elaborate. These sketches only need to give you an overall / general idea of how your model will be shaped and what parts you may have to make and how those parts might fit together.

STEP-3. Plan your model’s assembly. This is an expansion on Step-2. As far as possible, figure out the sequence of steps you’ll need to follow to build your model. If you’ll find them helpful, produce more detailed sketches of your model, showing the sequence of assembly steps and specs for the size and shape of parts (basically, this amounts to making your own simplified version of a model kits assembly instructions). It will greatly simplify the process if you begin by breaking your model down into ‘sub-assemblies’. For example, in planning my Blaster Mk-IV model, I broke the project down into major components – a beam emitter housing & emitter tip, an internal lighting unit, a combination battery holder & cover, and the twin pistol grips.  Once you’ve identified the key elements of your build, it will be much easier to lay out plans for the overall project. Breaking your project into sub-assemblies will also make construction easier. Each sub-assembly becomes a separate building project of its own and allows you to focus on the detail and functions (if any) that are needed in that specific part of the finished model.

STEP-4.  Gather your materials.  Refer back to your project plans. Gather the materials you’ll need for making parts, any working parts you’ll need (switches, wires, LEDs, chaser boards, etc.), and any detailing items you need from model kits. This includes tools (Xacto knives, screwdrivers, drills, sanding media, a soldering iron, a hot-glue gun, etc.) and any adhesives you’ll need on hand (plastic cement, plastic welder, cyanoacrylate cement, vinyl cement, jewelers cement for clear parts, etc.). It will save time and prevent delays in the building process if you have all the items you need on hand before you begin construction of your model.

STEP-5. Make your parts. Preferably, work on one sub-assembly at a time. Make the parts you need by cutting flat parts out of styrene sheet plastic, balsa wood, or whatever other basic material you’re working with. Round rods, round tubes, and square tubes or flat / square rods, can be cut to size from pre-formed plastic or acrylic parts (Plastruct & Evergreen both make a wide variety of very useful pre-shaped plastic & ABS forms – L-beams, T-beams, I-beams, pre-cut narrow strips, tubes, rods, square and flat rods, etc.). Take your time, measure and cut parts as necessary. If you need several copies of a particular part, start by making a template of that part, then use the template to cut out the copies you need. Templates can be very useful for keeping the size and shape of parts uniform and consistent. For example, I used a standard circle template to size and cut out the flat plastic disk I needed to complete the front of the beam emitter unit on my Blaster Mk-IV. When I’d cut out my first side panel for the pistol grips, I used that as a template to cut out the other three copies of the side panels that had to be laminated together to form rigid sides for the grips. I also used the handle of an old Star Trek laser pistol to trace and cut out a template used to create the contoured shape of the Mk-IV’s pistol grips.  As you go along, test fit the parts you’ve made together. It will save a lot of grief if you make sure the parts fit together properly before you begin building the sub-assembly you’re working on. Test-fitting also applies to sub-assemblies. Plan ahead, but test fit sub-assemblies together before your final construction so you’re sure the sub-assemblies actually fit together. Do this as soon as possible, even before you actually complete a sub-assembly. The sooner you discover if you have a ‘fit’ problem, the less work you’ll have to do to correct the problem.

STEP-6. This is the fun step.  Build your model.  Use the parts you’ve made plus the pre-formed parts you need and build your model. If you followed STEP-3 and STEP-5 and constructed sub-assemblies for the major elements of your model, this step should be relatively easy as you’ll only have to combine the sub-assemblies to produce your finished model.

That’s the general, overall, process of scratch-building a model. Depending on what you’re building some steps may need more (or less) time and effort to complete. In every step, take your time and think as you go along – if something doesn’t look like it’s going to work out, don’t be afraid to rework the design or create different parts to get the job done. Never rush through the steps. Be willing to add or change details as you go along.

As I said earlier in this article, don’t let lack of experience hold you back. If you want to try scratch-building something for the first time, go for it! Above all, have fun with the process. Enjoy the challenge of building something that didn’t come out of a box and don’t be afraid to fail – this takes practice and a first attempt doesn’t have to be perfect.

EXAMPLES:  The photos below are some examples of some props and scale models I scratch-built.

BLASTER RIFLE Mk-IV  / Inspired by the movie Forbidden Planet

 

FULL SCALE SCI-FI PISTOL PROPS – MY OWN CUSTOM DESIGNS

 

ARCTURAN DEATH-RAY

 

 

BLACK BEAST RAY GUN

 

INSPIRED BY FLASH GORDON – 1930s MOVIE SERIAL, Flash Gordon’s Trip To Mars

 

 

FLASH GORDON / MARTIAN RAY GUN

 

OTHER FULL SCALE PROPS – VACUFORMED STAR TREK NEXT GEN DATA PADD

TNG PADD / VACUFORMED SHELL

TNG PADD – Vacuformed styrene plastic shell. Screen & buttons made in Photoshop. LED lighting blinks.

 

SCALE MODELS / OTHER MATERIALS / WOODEN FARM WAGON

Photos show how to scratch-build a wooden European farm wagon (circa 1940s) from balsa wood & using additional plastic parts for wheel & brake assemblies, with a hand shaped  copper wire limber.

1. Floor & Seat Area

2. Seat Area – close-up

 

 

 

 

 

 

 

 

 

Sides & Back Added + Plastic Details

Plastic Wheels & Brake Details + Wire Limber

 

 

 

 

 

 

 

 

 

Propulsion System / Tamiya Farm Mule

Farmer / Driver – MB Models Figure

 

 

 

 

 

 

 

 

 

Finishing Touches / Tools & Cargo

 

 

 

 

 

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CHOOSING THE RIGHT ADHESIVE

 

VIDEO:  ADHESIVE CHOICES for model building.

Over the passed five decades, plastic models have evolved significantly.  There are a wider variety of model kits to choose from, kits are more accurate and better detailed, and we’ve seen the advent of ‘multi-media’ kits that include parts made of materials other than plastic.  In addition, there are now an increasing number of ‘after-market’ kits – these provide additional detailing parts for a specific model kit or series of kits. ‘After-market’ / detailing kits can be plastic, but more often are machined metal, cast resin, cast plaster, or photo-etched brass.

With the different materials available for building models, it’s important to select the right adhesive(s) to provide secure bonding of the parts of your model. In the late 1950s & 60s there was basically one adhesive for building models, ‘plastic cement’. Today there are a variety of adhesives available to deal with model parts made of styrene plastic, rubber, machined or photo-etched metal, cast resin, or vinyl.

Here’s a quick guide to the major classes of adhesives you can use for model building:

BASIC PLASTIC GLUE / CEMENTThis adhesive has been around as long as injection molded styrene plastic kits. It’s made specifically for joining plastic model parts. It’s still made today, and works well.  I always used TESTORS Plastic Cement when I was a kid. This product is still available today, but the formula was changed (1960s, 70s?) because kids were ‘sniffing’ the glue to get high.  The current formula works like the original, but you can’t get a buzz from it.  You can still get the original gel formula in a tube, as well as a newer liquid version. Like many adhesives, both these formulas come with flammability warnings.

Like all ‘glue’, plastic glue or cement works like double-sided Velcro. When applied to a plastic part, the cement grips the surface of the part. When you press a second part to the first one, the cement grips the surface of that part and holds the two parts together. The parts actually remain separate, joined only by the film of ‘glue’ between them. The strength of the bond between the two parts depends entirely on how well the glue / cement has gripped each part.

PLASTIC WELDER:   These chemical adhesives work differently than ‘glue’ and produce far stronger bonds between plastic parts. As the name implies, these adhesives ‘weld’ parts together. Applying a ‘welder’ to a a plastic surface causes it to soften / melt. When a second part is placed against the adhesive, it also softens. The two parts then fuse together directly.  You have to be careful when using plastic welders, applying too much can melt, distort, or destroy small plastic parts. Plastic welders are not recommended for use with vinyl models or vinyl parts included in plastic kits because the material is too soft and can be damaged by the welder solution. However, if you follow the product’s package directions, these types of adhesives are extremely effective and produce bonds that won’t separate with age like plastic cement can.

Currently I’m using a product called Same Stuff, marketed by MicroMark (see the LINKS section for a web connection). Like basic plastic cement, welders come with safety warnings and you should read all directions before using a welder product.

CYANOACRLATE CEMENT (AKA  CA):   CA is an outgrowth of the original Crazy Glue formula.  CA cement comes in a variety of formulas. There are liquid CA cements with different degrees of viscosity.  CA cements can bond virtually any material or combination of materials together.  Thicker liquid CA is often marketed as a ‘gap filler’.  It’s just thick enough to work into small gaps between parts and fill them when it dries. Yes, it dries hard enough to be sanded smooth.  Thinner CA formulas (closer to the consistency of water) make strong bonds between parts and can even be inserted between parts that are already touching (capillary action ‘sucks’ the cement into the space between the parts).  There is even a CA formula made specifically for plastics and works with styrene, ABS, even polycarbonates.  My personal favorite type of CA is ZAP-GEL.  This is a thick gel formula.  It has the advantage of staying exactly where you put it – it won’t run or drip like CA liquid can.

One advantage to using CA cements is that it takes very little to produce a strong bond between parts.  Regardless of the formula, the recommended application is only one (1) drop per square inch of surface to be bonded. CA has a few drawbacks, though.  It dries into a crystalline matrix, which is a bit brittle.  Dropping a model can possibly shatter the CA, causing parts to fall off your model. However, a little sanding and a re-application of CA can usually repair such accidents.  The other problem with CA cement is that it does bond just about anything it comes in contact with – including skin.  If you get this stuff on your fingers, you might bond them together.  Luckily, there are chemicals to counteract this problem.  There are several CA de-bonder formulas on the market.  They dissolve the CA crystalline matrix and allow you to separate model parts (or your fingers) without damaging anything.  You can also use a good nail-polish remover as a de-bonder.  One other chemical product is useful when building with CA cement.  A product called ZAP-KICKER is a liquid (available in bottles or spray cans) that hardens CA cement on contact.  It’s very useful for those situations where you want your cement to dry fast (immediately).

MULTI-PURPOSE & VINYL GLUE:  Loctite brand’s Stik ‘N Seal  is a multi-purpose adhesive marketed for joining metal parts, ceramics (broken vases & such), wood, glass, rubber, leather, masonry, and plastics.  The product comes in an Indoor and a water-proof Outdoor formula.  Either is fine for building models and can be used to join parts made of different materials (e.g. plastic & metal). Stik ‘N Seal is a non-corrosive paste.  It goes on white, but dries completely clear.  Being non-corrosive makes it perfect for working with vinyl models or vinyl parts of plastic kits (great for attaching rubber tires to plastic wheels, or for joining the ends of vinyl / rubber tank tracks).  Stik ‘N Seal has one drawback – a very slow cure time.  The directions tell you to let parts joined with the paste sit undisturbed for at least two (2) hours.  Full curing time is 24 hours.  Still, the product works well enough to be worth considering if you have to work with vinyl parts, clear parts, or other materials that might be affected by more corrosive adhesives.

G-S HYPO CEMENT (AKA Jewelers Cement):  G-S Hypo is often referred to as jewelers cement because it is used by jewelers to repair watches when a new glass lens has to be attached to a metal watch body. This is a thin gel formula that is applied with great precision through its built-in hypo needle tip.  The gel produces a very strong bond and is perfect for attaching clear parts to plastic models because it dries crystal clear and won’t yellow with age (use on window panes in buildings, car & truck windows, aircraft windows or canopies, spaceship or UFO windows, and so on) .

GENERAL PURPOSE GLUES:   Elmer’s Glue is a prime example of a general purpose glue that can be used in the model building process.  Currently, Elmer’s comes in three main formulas.  There’s the original ‘white glue’ or ‘school glue’ formula.  This is great for bonding paper, cardboard, and other light weight materials (works great for putting up propaganda posters on building walls in W.W.-II dioramas).  A more recent form of Elmer’s is its CLEAR formula.  This starts out clear and dries clear.  It can be a cheaper alternative to using G-S HYPO Cement for attaching clear parts to models.  Lastly, there’s Elmer’s Wood Glue, or carpenters glue.  This makes very strong bonds when applied to almost any kind of wood surface, but can also be used to join other materials to wooden surfaces.  In terms of model building, it’s great for constructing wooden doll-houses, small scale wooden buildings, wooden bridges, wooden crates, and so on.

Both the white glue formula and the wood glue can also be used to create very simple landscapes directly on a display base. Just spread a thin, even, layer of either glue onto the display base.  Let it dry just enough to get tacky; you can apply more to build up parts of the landscape (for large rises or deep ruts, apply over foam or Celluclay forms). Cover the tacky glue in a layer of sand, or gravel, or static grass, or any combination thereof.  See photos below for examples of ‘glue based landscaping’.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

HOT GLUE:   An article on modeling adhesives wouldn’t be complete without giving a mention to ‘hot glue’.  This is the only adhesive that starts out as a solid, usually in the form of a short cylinder.  Once melted, hot glue can bond almost any material to any other material.  There are three (3) small drawbacks to using hot-glue.  First, you have to invest in a hot glue ‘gun’ to melt and apply the glue.  If you aren’t going to use hot glue on a regular basis, this can be financially inefficient.  Second, it’s not always easy to apply hot glue with any measure of accuracy.  The nozzle of a hot-glue gun is often difficult to get into small spaces and it takes practice to eject just the right amount of glue from the gun.  Third, it’s hot!  Thin and small plastic parts can be warped or damaged by the heat from this adhesive, and it takes time to cool down (slow curing).  However, if you’re working with metal parts, hard acrylic parts, or other heat resistant materials, hot glue can provide a strong and lasting bond.   TIP / TRICK –  Keep a can of Dust Off (or a similar ‘canned air’ product) on hand.  Apply hot glue and join the parts you’re working with, then turn the Dust Off can upside-down and spray a small amount of propellant onto the hot glue. The propellent is cold enough to freeze the hot glue on contact, causing it to set immediately (or very nearly, depending on how much you spray on).

Check out the YouTube video for this article for more details and illustrations.

 

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