Start with the basics to get the most out of your tracked armored fighting vehicles
Building armor can be challenging. Some model tank kits have hundreds of parts, including resin and photo-etched metal, and difficult camouflage schemes. But basic tank model kits offer a good introduction to the most important modeling skills, so they can be an excellent way to get started. For instance, a Trumpeter 1/35 scale KV kit is a good choice because it has optional vinyl tracks and a single-color paint scheme.
Make a plan before building model tank kits
Look through plastic model tank kits instructions and get a general idea of the order of assembly. Familiarize yourself with the symbols used in the instructions. Some are self-explanatory, but you may need to refer back to the key for others.
Watch for optional parts; some model tank kits allow you to build more than one variant of a vehicle. Also, check ahead for steps that should be performed before others, like drilling holes.
Removing plastic model parts from the parts tree (sprue) and parts cleanup
The basic tools you’ll need to remove parts for model tank kits are a hobby knife, sprue cutter (also known as a side cutter), and sanding sticks.
For large, sturdy parts like the model tank kit’s hull sides, place the flat side of the sprue cutter near the point where the attachment point meets the part and squeeze the jaws together.
Even the closest cut leaves a small bit of the sprue attachment point that will be obvious on the finished model or will interfere with a part’s fit.
To remove the excess plastic, start by trimming the model tank kit’s part with a sharp No. 11 blade. Be careful: It’s easy to cut too deep and gouge the part. And never cut toward yourself—hobby knives are extremely sharp.
A few passes with a medium-grit sanding stick should smooth the surface. Make sure you don’t remove more plastic from the plastic part than necessary, or you’ll have to fill an uneven spot near the seam. Work slowly and remove a little at a time, checking your progress often.
Opening flashed-over holes
Many model tank kits have optional parts to model different versions of the vehicle. The locators for those parts are often molded with the hole covered by a thin layer of plastic. Round ones can be opened with a drill bit in a pin vise. To open square locator holes on a model tank kit hull side, I pierced the thin plastic on all four sides of the hole with the point of a knife from the back side of the part.
Turn the part over and clean up the opening from the other side.
Test-fitting a model tank kit’s parts before applying glue is an important step that reveals problems with fit. It gives you a chance to correct fit issues and minimize gaps and filling. Here, something is interfering with the fit and causing unsightly gaps.
The cause was ejector-pin marks (circular marks left by the molding machine) on the back of the model tank kit’s parts. Although they're recessed, a raised lip on several prevented the parts from meeting. A few vigorous strokes with a sanding stick or sandpaper removed them.
Glues and mold seams
You’ll need three types of glue to build model tank kits: liquid cement with a metal applicator (Testors or Revell work well), extra thin liquid cement (like Tamiya or Plastruct), and superglue. To join large parts with expansive gluing surfaces, use liquid cement. Apply this cement to both surfaces and spread it with the metal tip. If it clogs, use a lighter to clear it out.
Now, push the model tank kit parts together and make sure they fit all the way around. The gap here would have been difficult to fix if it had gone unnoticed.
Mold seams are ridges of plastic left where tooled molds parts meet during manufacture, and they are frequently found on round parts.
You can remove mold seams from the parts in model tank kits with a few strokes of a sanding stick.
Pay attention to how parts are supposed to go together. Here, the model tank kit’s rear hull didn’t look like it fit when test-fitted because the lower lip protruded below the lower plate rather than being flush. Examination of the part and the subsequent construction diagrams showed that was the way it was supposed to be.
After applying the glue, I pushed the rear hull into place and discovered minor gaps along the edges. Applying pressure to the hull sides closed the gaps. There are commercial model clamps available, but rubber bands can work just as well to keep model tank kit parts snug until the glue set.
Sometimes, the smaller parts in model tank kits have flash—thin plates of plastic caused when plastic leaks out of the mold during production. It’s easy to remove with a hobby knife and sanding sticks.
Attached return roller arms and other small parts on model tank kits by holding them in position and touching a small brush of liquid cement to the gap. Capillary action pulls the thin liquid cement into the join.
Tweezers are ideal for positioning small parts, and you should have a pair in your modeling toolbox.
Filling gaps and holes
The last major part of the hull is the engine intake cover at the rear. Here, you can see there is a large gap on one side.
In such a case, liberally apply liquid cement to the gap between the model tank kit’s parts, snug them together and hold them in place with a lightweight plastic clamp.
The liquid cement will ooze out of the join, but that’s OK! It melts the plastic and fills the gap. Let it thoroughly set.
Scrape excess plastic of the model tank kit’s parts with a hobby knife and smooth the seam with a sanding stick.
Sinkholes are shallow depressions left in plastic surfaces as the plastic contracts after molding. They are not supposed to be there.
Fill sinkholes with solvent-based modeling putty—there are several brands available, including Tamiya, Testors, and Revell, all with similar properties.
Use a metal spatula to place more putty than you need to fill the sinkhole in the model tank kit part. The reason you want more is because the putty shrinks as it dries.
Putty takes several hours to dry completely. Letting the model tank sit overnight is a good bet. After it’s dry, smooth the putty flush with the surrounding surface with sanding sticks.
Repeat the process to fill ejector-pin marks anywhere they may be visible, like under the fenders of model tank kits.
The model tank turret
Many model tank kits include two-part plastic gun barrels. You’ll want to eliminate unsightly seams without sanding the barrel out of round. To minimize sanding, run thin liquid cement down the join and squeeze the parts together, forcing the glue to ooze from the gap.
Shave off the bead of plastic after the glue sets with a No. 11 hobby knife blade and lightly sand it. Here, the model tank kit’s barrel is divided into three segments by engraved rings not on the full-size tank. They were filled with putty.
To prevent the barrel from going out of round with uneven sanding, twist the barrel against folded sandpaper.
Delicate parts like turret ladder rungs are best handled separately from other parts to avoid breaking them.
It’s easy to damage thin parts in model tank kits when removing them from the parts tree. To avoid damaging them, use a fine razor saw and cut slowly through the sprue attachments.
Liquid cement might melt or distort small, thin, and fine parts in model tank kits, like these ladder rungs. To avoid this, attach the parts with superglue. Hold the part with tweezers, dip the attachment points in a small pool of superglue, and then position the part on the model.
Reinforce the join with a drop of superglue on each attachment point. This will ensure the part doesn’t come loose.
Some model tank kits include copper wire for two cables. Before cutting, twist the ends to get rid of any stray strands and then dip them in superglue to prevent them from unwinding.
The wire may be slightly too thick to fit in the plastic cable loops. Bore the holes with a drill bit in a pin vise. Now, the model is ready for painting.
Spray-painting model tank kits
For model tank kits, leave the suspension and running gear off to make sure you can paint behind them. Leave the suspension and wheels on the parts tree—spray paint cans are not precise. To keep paint off joining surfaces, mask them with Blu-Tac or Silly Putty.
Spray cans produce a lot of paint at once. Start spraying off the model and make one continuous pass holding the can 6 to 8 inches above the surface. Keep the can moving until you are past the model.
Do not stop or reverse the direction of spray on the model because too much paint will cause runs. Do not attempt to get complete coverage on your first pass. The model tank should look speckled.
The first pass with the spray can will leave the model not looking the best. It is better to build up the coverage with several light coats of paint rather than one, heavy, wet layer.
Final assembly
To finish model tank kits, first attach the running gear. Trumpeter’s KV keyed the roadwheel arms, so alignment is perfect. Apply a liquid cement; the slower-setting glue allows for adjustments.
Check the alignment of the suspension by placing the hull on a flat surface to be sure that all of the arms are touching. Nothing ruins the illusion of heavy armor like wheels floating above the surface.
Heat and water produce corrosion, so paint the exhausts a rust-colored paint.
Paint the inside of the headlight silver and attach the lens with Micro Kristal Klear or Testors Clear Parts Cement.
Return rollers have a thin tire. Carefully color the rubber detail with a permanent black marker to achieve a realistic sheen.
An easy way to produce a metallic shine for exposed metal rims on road wheels in model tank kits is to draw bare steel on the parts with a soft pencil.
Lastly, add the vinyl tracks. Carefully melt the attachment pins with the heated tip of a screwdriver. With that, you’re ready to display your model tank.
A version of this story appeared in
Essential Skills for Scale Modelers.