Deep Thoughts

Materials Knowledge: Avoiding The Flying Balls Of Flame

It must have been 1980, maybe 1981. A large wasp nest had appeared on the back area of our carport. I’d seen it, but in typical young teen fashion, I’d let it be to see how big it would get. And because my mom didn’t go out into the back of the carport often, she’d not seen it. It grew and grew, until it was quite large.

Somehow she got wind of it though, and told me I needed to get rid of it. Her failing was that she did not specify the “how” part. Just get rid of it. And to my mind, that meant I had a pretty wide open permission slip. Terminate with extreme prejudice. Ignore the collateral damage. Mission first.

Of course, she didn’t say all that, but I figured it was just implied.

In the past, she’d had me attach a sprayer on the water hose. I could then hose down the nest from a safe distance, clearing the wasps off, and run in to swipe it with a broom. The method worked. We’d done it plenty of times before. But it was so very boring.

So grabbing my younger brother, now freshly healed from the great Big Wheel incident, we headed out to the back of the house to begin planning and executing the mission. 

A thorough recon of the area showed a plate-sized wasp nest hanging from the underside of the carport, right at the edge. There had to be two dozen or more wasps on it, and they all got a bit edgy when we approached too close. It dawned on me that our old method – the stand-off hose method – did not solve the problem. The nest was not the problem. The wasps were. They had to go.

I went into our storage shed to look for bug spray. We had some stuff for ants, and some stuff for spiders. But nothing for wasps.

Then I saw my dad’s homemade “bug spray”. Essentially, he’d taken an empty spray bottle of some sort, filled it with gasoline, and used that to kill bugs from time to time. The appeal of using such a powerful weapon to defeat my foe was too great – I grabbed the sprayer full of gas. 

My little brother piped up. “What’s that?” I smiled at him. “It’s a sprayer full of gasoline. We’ll spray it on the wasps and they’ll die pretty quick.” I was quite pleased with my plan.

Then he asked a very important question.

The Plot Thickens

“Doesn’t gasoline burn?”

I stopped in my tracks. Yes, it does. Quite vigorously. With a plan forming in my mind, I ran in the house to get some matches. 

I’d been reading about something called a “fuel air bomb”. I didn’t quite understand it, but I did have a grasp that it involved fuel. And air. And fire.  And possibly a kid brother. All of which I had at my disposal.

Though my time serving in the Army was still almost a decade off, I was already in the mindset. First we needed to rehearse. I took my brother into the open space of the backyard, and told him my plan. He thought it sounded great. Of course, little brothers – at least mine – always thought older brother’s plans sound great.

The idea was simple – spray a big mist of gas into the air, throw a match in it – BOOM! Instant fuel air bomb. The wasps would be sizzled in a most spectacular fashion. I first showed my little brother how to flick matches off of the box, so they’d light in the air. I stepped back, sprayed some gas in the air, and he flicked his match.

The fireball was large, dramatic, and most glorious. It flashed a good three feet across, burned for a second, and then vanished. We tried it a few more times. I found I could get three good, full sprays of mist into the air before he lit it up. We were ready.

Carefully approaching the wasp nest so as not to disturb them, we got in position to launch the attack. With a knowing nod of grim readiness, I counted down…

“Three. Two. One!”

Three vigorous sprays into the air… my brother perfectly timing the launching of the match off of the box. Almost as if in slow motion, I watched with absolute glee. The fuel mist had alerted the wasps that something was up, and they all begin to take flight. Just as they were starting to clear the nest… the match hit.

As the fireball flashed before our eyes, big enough that we felt the heat, we let out a cheer!

Then a sinking realization hit us…

Is There A Modeling Point To All This?

When I returned to model build in 2006, after a 20 plus year break, I had quite a bit to re-learn. As a kid, I’d simply glued the kits together, painted them up a bit, added the decals, and then after a suitable amount of time playing with them – blew them up with firecrackers. 

As I got back to building though, I planned for my models to have a much more sedate future, one that involved sitting on my shelf, nicely displayed. And I wanted them to look good. So my plan was to paint them, of course.

Visiting a local hobby shop, I was most happy to see that many of the products I’d used as a kid were still around. There were Monogram models, and Testors paint and glue. Grabbing  kit and some paints, I headed back to the house. I was looking forward to getting started.

Arriving home, I opened the box, grabbed the sprues, and as any kid of the 70s would do, I begin to twist and turn the parts to get them off of the sprue. Starting in the cockpit, I opened my newly purchased bottle of zinc chromate green (yes, I know… it’s not an actual color…) slapped some paint on the parts, and dipped my brush in the jar of enamel thinner to clean it off.

Nothing.

The paint just clung to the brush. It made quite a gloopy mess, in fact. Puzzled, I took it over to the sink, and washed it under the water faucet. And it cleaned right up.

The sounds of the clutch plate of reality grinding against my cognitive dissonance made for a disconcerting cacophony. (Don’t ever say my articles aren’t scholarly endeavors… that there is a highfalutin sentence my friends! 🙂 )

It turned out some of the paints I had purchased were acrylics, which of course were water based. Others were the enamels I was used to from my childhood days.

As I began my journey back into modeling, I’d discovered something very simple, yet profound.

Understanding the materials we work with is very important.

Getting A Grip On The Materials

It would of course be quite foolish of me to think I could cover every nuance of material difference in hobby products in one article. Well… I suppose I could, but it would be so long no one would read it.

However, I believe I can make some distinct breakdowns for consideration, with a few examples, to help illustrate how to evaluate the products and materials you use.

The Stuff We Build

As modelers, we build models. (Duh.) Those models are generally made of various plastic, resin, or metal materials. Yet though a model may have all of those media present (and perhaps others), not all can be bonded with the same substances.

For the plastics, the most typical you’ll find is polystyrene (PS). According to Wikipedia, is a synthetic aromatic hydrocarbon polymer made from the monomer styrene. (But you already knew that, right? 😉 ) The glues we use to join pieces of that synthetic aromatic hydrocarbon polymer made from the monomer styrene generally work by slightly melting the plastic, so when it is pressed against another piece, the two form a bond – almost as if they were one piece. 

However, resin won’t react to that same type of cement. Wikipedia explains what resins are made of using many, many, many big words, but suffice to say… it ain’t plastic. And that glue that works so well with PS won’t make a dent in typical modeling resins.

Of course, all of this is obvious if you’re an experienced builder. But to the new modeler, the key takeaway is “what type of material am I working with? And what agent will bond it best?” 

For polystyrene, glues such as Tamiya Extra Thin Cement, or Revell Contacta, work nicely. There are of course other brands. For resin, various “super glue” brands are often used, or two-part epoxy mixes. Some kits, such as Bandai’s Gunpla kits, may contain ABS plastic. While it may look a bit like PS, it may not react to the cements that work for polystyrene, so you may need to get glue that is made for ABS, such Deluxe Materials Plastic Magic.

Of course, there are many solvents and substances you can use to join your models together. Learn which ones work best for the material you are using, and it will make for a much happier build experience.

With your model’s glue needs sorted out, it’s time to look at…

The Paints We Use On The Stuff We Build

There are so many brands and types of paint for use in our hobby that it is quite astounding. Yet for all the brands and colors and bottle shapes, you will typically be able to sort them into three very loose categories – acrylics, enamels, and lacquers. 

Lacquers will generally be thinned and cleaned with products that are “hot” chemically. Meaning they can be quite odorous and toxic if breathed in. Some lacquers use actual lacquer (or cellulose) thinners as you might find used in the industrial painting side of things. Others use a variety of chemicals that while not as potent as cellulose thinners can still be very harmful to breathe. Brands such as Gaia Notes and Mr. Color use the latter type of thinner.

Enamels use, oddly enough, enamel thinners. They are quite odorous in my experience. Brands such as Humbrol, Model Master, and Tamiya have lines of enamel paints that are quite common for modeling use.

Acrylics can be a bit of an oddball category. While most of them are water-soluble,  a few, such as Tamiya acrylics, are actually solvent based. While modelers tend to generically refer to “acrylics” as anything water based, knowing the distinction between them is critical. So while brands such as Vallejo and Ammo of Mig thin nicely with water, Tamiya is better thinned with products more associated with lacquers, and even alcohol works.

NOTE: IN ALL CASES, MAKE SURE YOU WORK IN A WELL VENTILATED AREA, AND WHEN AIRBRUSHING ANY PAINT, USE A PROPER RESPIRATOR TYPE MASK.

For the new modeler, learning which paints work together – or against each other – is critical. If you are sticking to one type, such as acrylics, then adding paint over paint is normally fine. If you work with mixed paint types, it’s important to understand drying and curing times. Drying is generally a reference to the paint being touchable. If you touch it and you don’t stick to it or leave a fingerprint, it is dry. However, curing is different. Curing is the process by which a paint is not only dry, but fully hardened and bonded to the surface it’s on.

As a paint cures, it will go through a process of “gassing”, which, mush like the human body, releases chemicals into the air. (Only without the humorous sounds… 😉 ) Applying another paint over a layer that is still curing can lead to cracks in the top layer, or even weird swelling of the paint.

Additionally, adding a “hotter” paint on top of one that is less hot can lead to problems if applied to heavily. For example, you may be able to lightly airbrush lacquer paints over fully cured acrylics. But if you try heavily brushing them – it will possibly take up the acrylic paint.

Yet this very problem can be turned to our advantage. Many modeling products, such as enamel based weathering washes, can be applied over an acrylic gloss coat – which is generally impervious to enamels – and then unwanted portions of the wash can be easily wiped away.

Suffice to say… understanding the various types of paints, and how they interact, is critical to building your models. Take a look at the paints you use, what they are thinned with, and how they interact with other paints and materials, and plan your builds accordingly.

All The Other Stuff We Use On The Stuff We Build

We’ve examined the models and their materials, the  paints and their makeup, so what is left?

Roughly a gazillion items. 😉

Gloss coats, matt coats, washes, decals solutions, masking materials, floor polish, hairspray and even toothpaste may be applied to your models for a variety of purposes. Every one of these will have some level at which they will react with the materials that have been applied, or are being applied later. While it does not require a chemistry degree to sort out, asking some very basic questions can help you assess the materials you use:

  • What can it be thinned with? This will help you determine how “hot” the product is, and how it will affect adjoining layers of material.
  • What is the drying time? Some products can have others applied over them when they are fully dry. Others may require special consideration, so you need to combine that with…
  • What is the curing time? As noted above, dry does not equal cured. Understanding how those two work is critical.
  • Does one thing melt/dissolve another thing? This is sort of a catch-all question. While you may not fully understand why Tamiya’s solvent based acrylics and Ammo’s water based acrylics can both be acrylics (I don’t…), knowing that trying to do a panel line wash with lacquer paints thinned with cellulose thinner over an acrylic base will melt the paint and the plastic is handy information. Seek to grasp the “don’t try this at home” basics.

Knowing Is Half The Battle

Getting back to the early 80’s… as the fireball flashed gloriously, the gaps in my materials knowledge began to show.

While I did know that gas would burn, and that gas mixed with a volume of air would burn fantastically, I had not considered that the materials wasps are made of seemed to be temporarily immune to the effects of flaming petroleum. Though it would sit on them and burn nicely, the immediate effect during initial combustion was to simply enrage them. And as they took flight – now covered in flames – their discontentment was aimed squarely at my brother and I.

Discretion being the better part of valor, and running being the stuff of self-preservation, I quickly decided that the spectre of a horde of angry, flaming wasps attacking me was the signal to run away as fast as possible. I did have enough thought for my little brother to shout “RUN!”, but though only 7 years old, he was bright enough to recognize the problem also. 

So beat feet we did, making a hasty retreat.

The wasps of course pursued, intent on inflicting much harm to the interlopers of their wasply activities. As I looked over my shoulder, I could see them in… well…. hot pursuit. And gaining on us.

Thankfully, another piece of material knowledge that had slipped my mind was working on our favor. While flaming wasps can be quite a fright, flaming wasps whose wings have burned off lose much of their potency. One by one they began to drop, bowing to the basic aerodynamic principles of lift, thrust, drag, and weight. Essentially, as their wings burned off, the weight became to great to compensate for the lack of lift, and down they went. The little flaming pyres that marked their bodies dotted our driveway.

Reduced to walking, they were now easy prey to our stomping. And stomp we did. Laughing and congratulating each other in our great victory, we headed back down the driveway. Only to be confronted by some more gaps in materials knowledge.

It seems that spraying flaming gasoline on to the side of a house results in what is known as “idiot kids burning their house down”. Thankfully I was able to beat the flames back with my t-shirt and little brother, leaving only a bit of scorched paint. (On the house, not my brother.) Still, the materials lessons were not over.

When my mom found out about our escapade, she reintroduced me once again to the elementary principles of the interaction of a switch  and my backside. (Basic summary… some redness and inflammation will occur, as well as soreness.)

So whether it be in the quest to battle household pests, or in your models, thorough knowledge of the materials we use is quite critical. When you are armed with the right information, you can make good choices that result in excellent outcomes.

All the while avoiding flaming insects, burnt houses, and scorched backsides. 😉

Wasp photo is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. Photo by Joaquim Alves Gaspar.

 

2 comments

  1. Terrific article…I have lost sight of this just recently even after 40 years of modeling. A well thought out reminder post and much appreciated!

Leave a Reply

Your email address will not be published. Required fields are marked *