Aircraft In Progress Tutorials

Masking Canopies With Parafilm

When you’ve built more than 250 aircraft models, one of the benefits is the many, many, many opportunities to mess things up. Often royally. But there’s a silver lining in that cloud- it also means plenty of chances to try different things. And when you do find one that works- the choice of sticking with it is easy.

(Now- I know modelers. Everyone is different. Everyone has different tastes and preferences. So what I am about to describe may, for some, be the worst method they’ve ever tried. I get that. So please keep in mind, in my experience, this has worked better than anything else I’ve tried. )

When I’d first returned to the hobby in 2006, I wondered what others did about masking canopies. Checking various magazines and websites, as well as listening to shared experiences, revealed a wide variety of methods being employed. So being a bit of a “mad scientist” modeler, I tried many of them- and ultimately moved on from each. 

In no particular order, I tried:

  • Hand painting- I have shaky hands and poor eyesight up close. That one was discarded after about half an attempt.
  • Masking fluid- In theory it sounded good, but it was very dependent on well defined canopy frames, masking fluid that flowed well off the brush, and…. good eyesight up close and not shaky hands. I moved on.
  • Masking tape- And not just any masking tape- Tamiya yellow tape. I actually tried two variants of this.
    • Cover the entire canopy and cut away what you don’t need. This worked fairly well, though at times it could be difficult to see exactly where to cut the tape on some canopies. Once in place, it masked everything nicely. However, when removing the tape, it could be a bit “grippy”, and frequently left a bit of residue that a simple rub down could not fully remove. Not really enamored with this technique, I looked around for an alternative, and found…
    • Cut up itty-bitty bits of tape and place them on the canopy. The friend who told me of this one was so wide eyed (almost crazed, actually) about how completely awesome this technique was I felt no small amount of fear that I must try it- or else. 🙂 So I dutifully cut up pieces of tape, applying them in quilt like fashion. It did mask things nicely, but it also had its drawbacks. For corners and rounded edges, it meant cutting many tiny pieces. And then when applying them, they all had to be lined up, or a somewhat jagged edge would result. And removing them was a bit of a pain, too. So I moved on.
  • Bare Metal Foil- This one made a lot of sense intuitively. Bare Metal Foil is pretty much what it says- a very thin sheet of foil with a sticky backing. You cut off a section, peel off the backing paper, apply it to the canopy, burnish it down, and cut away. The canopy frame detail is very easy to see, and the foil is so thin it slices easily. However, BMF was a bit expensive, and I found that over time, my nice, neat sheet of foil began to crackle, and made those sections useless. And the residue the pieces left behind was not “removal friendly” in every case. Another solution was needed.
  • Pre-cut canopy masks- A-ha! I found my solution, right? Well… maybe. It was still made up of tape, in most cases, and did leave some residue. And some canopy masks did not always fit correctly. In a few cases, you have to wonder if the designer had actually seen the aircraft model’s clear parts at all. And unless they came with a kit, they were basically an added expense that I could not always afford.

So what is a cheap modeler to do?

Enter Parafilm M

Now, I have no idea what happened to Parafilm A through L… perhaps those were the ones that didn’t work. (Like Preparation A-G… 😉 ) But the “M” version does work, most assuredly. Parafilm M is a stretchable, slightly waxy roll of… err… stuff, for lack of a better term. It’s made for use in laboratories for things that probably require more education than I have. You know, beakers, bunsen burners, mad scientists… that old chestnut.

But for modelers, it is remarkable. It can be applied to a canopy, burnished down neatly, sliced through easily, painted over confidently, removed handily, and purchased economically. (I hope you’re impressed with my neat collection of words that end in “ly”.)

From a cost perspective, Parafilm M is great. A roll that is 2 inches wide and 25 feet long goes for US$11.95 over at MicroMark.com. And that roll can last a LONG time for most modelers. In all the models I’ve built over the years, I’m just getting to the end of my 2nd roll of Parafilm. So that’s over 100 model aircraft, mostly in 1/48 scale, per roll. (And I have used large sections of it for other masking.)

For ease of use, I find it the simplest of all to apply. Stretch, set in place, press down, and cut. It burnishes far easier than masking tape, and is much more sturdy than foil. It’s thin enough to slice easily, yet can be stretched and nudged if need be.

When removed, if there is any residue, it is simply a slightly waxy substance that comes off completely with a dry cotton bud.

Suffice to say, in my experience, I’ve found it superior to any other masking method- including commercially produced masks.

Well All That Is Great, But….

How do you use it?

I’m glad you asked.

First, you’ll need a handy roll of Parafilm M, an hobby knife with a fresh blade (always fresh!), and of course, the canopy parts in question.

Cut off a piece of Parafilm that will be large enough when stretched to cover all the canopy parts. With a few uses, you’ll get better at estimating how much is needed. Remove the backing paper.

Grabbing the strip of Parafilm by the edges, stretch it out. You’ll notice the waxy, slightly opaque surface will become noticeably more transparent. When the part being stretched has lost that opaqueness, you’ve stretch it far enough. (If it tears, don’t panic. You can still use it!)

Slice the stretched Parafilm into smaller parts for each canopy section.

To apply it, first place it loosely over the canopy. Don’t stretch it over it- just lay it on top. 

Next, began to press it down firmly into all the nooks and crannies. I like to place my index finger inside the canopy part to brace it, and then press the Parafilm in place with my thumb. The heat from your hands will actually help the process. If you see a small air bubble forming, either work the bubble to the edge of the part, or work it to the nearest frame edge, and simply make a small incision to allow it to “vent”.

You will have excess hanging from the canopy edge. You can either tuck the edges underneath the canopy, or cut the excess away. I have done both methods, and generally I just do whatever I feel like doing at the time. If you tuck too much underneath, it can make seeing finer frames a bit more difficult, so figure out which method you prefer. Below, you can see both methods- the “tuck under” being used on the larger canopy part.

 

Once the Parafilm is in place, place the tip of your fresh hobby knife blade at about a 45 degree angle into the canopy frame’s edge, and begin to slide along the frame. In some places, if the frame is not very prominent, you may not be able to do that. At those times, I turn the canopy and knife blade so that I slide the knife in a downward motion, with the blade parallel to the canopy frame. Just go slow. If the knife is not slicing, but tearing- you forgot to put in a fresh blade. (Or it’s just not a very good blade to start with.)

As for pressure, I use enough to slice the Parafilm, but not so much as to gouge the clear part. It’s definitely not just the weight of the blade- I do press down. With a few attempts, you’ll find the sweet spot.

I’ve also found that working a section at a time helps. It’s best to make a full cut, without stopping in the middle, because this can lead to jagged edges or weird angles. For example, if I’m cutting along the lower section of canopy frame, I’ll make the cut from one edge to the other, without stopping. (Even if it means “going past” intersecting canopy frames.) And at the end of the cut, I always go slightly past the frame line, so that any intersecting cuts will be complete on the corners.

Once you have completed all the cuts, use a toothpick or the point of your hobby knife to remove the Parafilm and expose the canopy framing. I’ve found I prefer to make cuts so that I can remove the outer edges together, then vertical canopy framing, then horizontal. (Or vice versa…) I have tried removing the entire cut section at once, but if there are any incomplete cuts, it can lift off part of the mask you want to keep.

If that does happen- STOP. Place the Parafilm back in place over that section, complete the cut, and move on. If a larger section does come up, and you can’t get it back down, make a few cuts to loose the rest, and finish unmasking the rest of the canopy. Then, simply get a leftover bit of stretched Parafilm, cut a section small enough to cover the errant area, and cut the sections away. Parafilm adheres nicely to itself, so making small corrections like that is dead simple.

Once it’s all removed, well… you have your canopy masked!

You can then apply it to the model with the glue of your choice. I prefer Tamiya Extra Thin Cement. (Yes, really. No, it does not fog, unless you are too heavy handed. No, the canopy does not need to be dipped in Future first.  🙂 )

Some final thoughts:

  • When I first read about this technique, the article that prompted me to give it all a try insisted that a double layer of Parafilm was required. Being the adventurous (and cheap) modeler I am, I tried it as a single layer. It worked fine, so I stuck with it.
  • I have sprayed acrylics, enamels, and lacquers over Parafilm. Acrylics work just fine. Enamels and lacquers have not been much of a problem, though they can make the Parafilm a bit “crispy” when being removed. I’d definitely recommend NOT applying lacquers in a thick coat, but rather in thinner coats that can dry quickly. (In fact, even though I’ve not had a problem, I have gotten to where I avoid the use of lacquers in general, so that solved that.)
  • Parafilm can be used for other masking. For example, I’ve used it plenty of times to mask a section of wing or fuselage, cut along some panel lines, and airbrush another color.
  • It works great over decals, because unlike tape, which can pull them up, Parafilm does not stick to markings.
  • I’ve not found it so great for masking off camo patterns. Because it needs to be sliced after stretching and application, even the gentlest pressure can leave knife marks in the underlying plastic or primer.
  • While there may be other products like Parafilm M, I’m not aware of them, and really haven’t searched, to be honest.

While there are many methods for masking canopies, I’ve found Parafilm M to be my “go to” product of choice, nearly every time. (One notable exception being the ball turret on a 1/48 TBF Avenger… pre-cut mask all the way on that!) It’s affordable, easy to use, reliable, and offers great utility beyond just the masking of canopies.

Give it a shot, and see if you like it!

4 comments

  1. Hi John,
    A very informative and entertaining article, many thanks for sharing the Parafilm technique, the very thought of painting canopies give me sleepless nights!
    Cheers
    Anthony

    1. Glad you enjoyed it, Anthony, and thanks for the honor of a read!

      Canopies can be a bit of a headache. While no method is perfect, this one has let me get get (mostly) restful nights! 🙂

  2. Jon, fantastic article. I will try that if I ever get back to building aircraft. Armor is so easy for me.

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