How to assemble a plastic model kit

Several months ago I bought a plastic model kit for the first time in probably 20 years. This past week I started to put it together.

I’m doing things differently this time.

Wash the parts

Plastic models have mold release on them, which makes it harder for paint and glue to adhere to the parts, making for a weaker model. The first step to building a proud model is washing the parts with dish detergent. Then avoid handling them with your bare hands as much as possible afterward.

Use better glue

The guys at the local hobby shop argue about the best glue to use, but they agree that the Testors stuff that comes in the tube isn’t it. It’s better to use either a plastic welder like Tenax-7R, or one of the many super glues on the market. Tenax welds the plastic together and actually makes one piece from it. The downside is its nasty fumes (wear a ventilator to save your lungs and your liver–really) and its permanence. Super glues work about as fast but make a chemical bond. The upside to super glue is that if you make a mistake, you can put the mistake in the freezer overnight, and then you’ll be able to pry it back apart and glue it again.

The downside to super glue is that it happily glues skin, so get a debonder from your hobby shop to bail you out if you glue your hand to your model or if you glue a couple of body parts together accidentally–putting your hand in the freezer overnight doesn’t work very well.

Both glues result in a stronger bond than the old tube glues we used to use.

Trim the flash

There’s always extra crud on the edges of your plastic pieces, due to the molding process. Trim that away with a hobby knife. Usually just slowly running the blade across the edge is all it takes.

Putty

When you glue your pieces together, there are always gaps in them. You can get plastic putties that chemically bond with the plastic and those are the best to use, but even a household putty like Durham’s Water Putty is better than gaps. Ideally you want the putty to be a different color than the plastic so you can see your work better.

Use primer

You should always paint your model, even the parts that are molded in the correct color, for reasons I’ll get to. But before you paint, you should prime the model. Use a good-quality primer like Krylon or Rustoleum Painter’s Touch. They are less expensive than hobby primers and they work extremely well.

Primer does several things. Paint sticks much better to primer than to plastic itself, so if you use primer, you can use thinner coats of paint, and you can also use paints like acrylics that normally won’t stick well to plastic. Second, primer can fill in minor flaws in the plastic, and make flaws that need to be puttied more visible. Third, primer makes the detail much more visible, which helps you paint better.

Spray on a very thin coat. It doesn’t have to cover completely.

Paint

Models should be painted for two reasons. The real thing is painted, so your model will look more realistic if it’s painted. Bare plastic looks more like a cheap toy. Second, decals don’t adhere well at all to bare plastic, because they are designed to adhere to paint.

The best paints to use is also a matter of religious debate. I like to use acrylics for the parts I have to brush paint, because acrylics have no fumes and clean up with water. They’re cheap and easy to work with. I can get craft acrylic paints for 60 cents a bottle if I shop around, and the bottles are big enough that they last forever. They’re cheaper than Testors enamels normally sold for models, and I don’t think they dry out in the bottle as quickly.

For the ultimate acrylic, visit a hobby shop that caters to wargamers and pick up some Vallejo paints. They’re thinner than the craft acrylics, so they’re less likely to obscure detail when detail counts. They also tend to be self-leveling, helping to conceal your brush strokes.

I prefer to spray rather than brush whenever I can, because then I don’t cover up as much detail, and I don’t get brush strokes. I can spray a light coat followed by a second light coat and get nice, even coverage. You can get sprays intended for plastic models at a hobby shop, but if you can find a suitable color from Krylon or another hardware store brand, you can use it.

An airbrush is nice, if you can afford its cost and can afford to invest the time required to learn how to use it and keep it clean.

So, should you paint before or after assembling the model? I find it easier to paint what I can before, and scrape the paint off the surfaces that need to be glued.

What if you really mess up the paint? There are ways to safely remove paint from plastic so you can start over.

Masking

When you need to paint an assembled model and you need to keep the paint away from parts of it, use masking tape. Don’t use the cheap beige stuff. Get some good blue or yellow painter’s tape, which is less likely to lift the paint that’s under it.

To keep paint from bleeding under the tape, you can either brush along the edge of the tape with the color that the tape is covering, or brush with some clear acrylic medium (look for it in the artist’s paint section of stores like Michael’s and Hobby Lobby) or, believe it or not, Future Floor Polish. This seals the edge, and if any of it bleeds under, it won’t be visible.

Decals

Dad and I could never get decals to stick right. What we didn’t know was that decals are nothing more than a clear lacquer sprayed on paper with something printed on it. They are supposed to bond permanently with paint underneath them.

So the first secret of applying decals is just to paint the surface beneath them. Decals stick better to glossy paint than flat, so if you don’t paint with glossy paint, apply a bit of acrylic gloss medium or Future Floor Polish (which is actually a clear gloss acrylic, not a wax), let that dry, and then apply the decal to that.

I have some additional waterslide decal tips and tricks if you’re interested in them.

Clearcoat

When you’re done, spray a clearcoat over the whole paint job. This gives a consistent and more realistic finish. A gloss coat is fine if you want your model to look factory new. But for a more typical real-world look, use a clearcoat with a dull finish. Testors Dullcote is the standard.

Before you experiment with Krylon or another hardware store clearcoat, take some scrap plastic, paint it with the same paints you used to paint the model, and then spray the clearcoat over it. Not all clearcoats are compatible with all paints. I once tried Dutch Boy clearcoat on a plastic model and it caused the paint to bubble, ruining it.

Following these tips won’t make award-winning models, but it will make your models look a lot nicer.

3 thoughts on “How to assemble a plastic model kit

  • October 23, 2006 at 8:22 am
    Permalink

    I was actually looking at models myself at a local hobby store recently (for the first time in what ? 35 years ? 😉

    One of the things that really popped out was the price. Esp. for the higher quality, Japanese brands I used to like (e.g. Tamiya). Yowza!

    • October 24, 2006 at 3:41 pm
      Permalink

      No kidding. I’ll be using a 40% off coupon from Hobby Lobby to buy my next one, in all likelihood. I’m having fun building this one though.

  • November 2, 2006 at 10:45 pm
    Permalink

    On decal setting solution — I was amazed at the results the first time I tried it. When I applied some decals to a model rail car, the setting solution sucked the decal down tight over frames and rivets like the lettering had been sprayed on. That’s cool stuff.

Comments are closed.

%d bloggers like this:
WordPress Appliance - Powered by TurnKey Linux