Testing out Auto Paints & Primers on PP and PS plastic

 Sometimes a seemingly inconsequential circumstance (the case in point being my inability to find a specific hobby paint color i.e. Tamiya Mica Blue for some recently acquired car scale model kits) will kick off my inane hobby OCD behaviour. With so many miniature projects pending you might think I would just put sourcing the out-of-stock paint on the back burner and concentrate on the huge pile of ongoing projects. But no. Cue a search online for an alternative, resulting in a significantly cheaper yet not necessarily wholly ideal solution. Let me explain ...  

Spray Man (Subaru WRX OC2 Blue) automotive grade paint on a polystyrene spoon

 My quest for an alternative paint began with a search for an extremely specific hue i.e. the dark blue metallic hue that's iconic to the Subaru Impreza WRX STI. So my primary concern wasn't the type of paint available but more towards the color of the paint. Any worry of whether the paint is suitable for scale model kits became secondary to color accuracy. Subsequent research paid off in the way of automotive grade primers/paints as an alternative to the plastic-friendly hobby lacquer primers/paints. These are the Spray Man Automotive Grade Paints and Primers you see below.  

Spray Man Automotive Primers, Paint, and Clear Coat

 It has been quite a while since I used aerosol spray paint cans, and I was quickly reminded about how messy things could get while using a spray paint can. Naturally, I made a right mess of things and the cement floor at the front of the house now has Subaru WRX STI blue paint on it. Oops! Meanwhile, a unique feature of this particular brand of automotive spray can is that it comes with two different types of interchangeable nozzle. One sprays out a flat horizontally-shaped layer of paint while the other sprays out a circular-shaped layer of paint. The latter is what you would normally find on hobby spray paint cans. In this test, I used the flat-horizontal spray nozzle.  

Applying automotive grade paint via a spray can onto a primed plastic spoon

Cardboard boxes and pieces used to prevent paint over-spray from damaging the house ...  

... but unfortunately the missus won't be best pleased with the results of my overzealous testing

 On what surface were the automotive grade paints/primers tested on? Well for the tests to be effective and useful, the paints had to be sprayed onto plastic that were as close as possible to the types found in scale model kits. Unless you're using spare plastic sprues or parts from the model kit in question, it is almost impossible to 100% match the type plastic found in my test plastic spoons. For example, even though most model kits use Polystyrene (PS) molded parts, the characteristics of said parts differ from brand to brand e.g. some brands have softer PS parts than others.  

Plastic Recycling Symbols for Polypropylene (PP) and Polystyrene (PS)

 In my case, I have scale model kits of the Subaru Impreza WRX STI from two brands, namely Tamiya and Aoshima. As I understand it based on a perusal of plastic symbols found in the Japanese language box art and instructions, Tamiya uses mainly PS plastic while Aoshima uses PP plastic. For the closest comparison I could muster, I used PS and PP plastic spoons to mimic Tamiya and Aoshima molded parts respectively. [Caveat: While the spoons and molded parts may comprise similar types of plastic, their specific characteristics may differ slightly from one another.]   

Polypropylene and polystyrene plastic spoons I had saved from takeouts and visits to eateries

 Prior to achieving a successful outcome of sorts, there were plenty of failures along the way. The one common theme of said failures is the ineffectiveness of lacquer-based hobby primers be it Mr.Hobby Mr.Surfacer/Mr.Fine Surfacer or Tamiya Fine Surface Primer in withstanding the application of either an automotive grade filler primer or paint, when used in conjunction with PS plastic spoons. For automotive grade paints to work on PS plastic spoons, first an automotive plastic primer needs to be applied on the spoon, followed by an automotive filler primer. Once both primers have been applied, the automotive paints will adhere to the PS plastic spoon fairly smoothly.  

Experimenting with Hobby Primer and/or Auto Filler Primer/Plastic Primer on polystyrene spoons

Testing Auto Paints on Mr.Surfacer 1200, Tamiya Fine Surface Primer, and Auto Filler Primer

 Using the two-step priming process (i.e. automotive plastic primer followed by filler primer), the application of automotive grade paints also work when used in conjunction with PP plastic spoons. But there is a significant advantage to using PP plastic. As you can see (in the photos immediately above and below this paragraph) PS plastic spoons primed directly with automotive filler primers do not exhibit the necessary surface texture that allows the automotive grade paint to adhere properly.

However, when PP plastic spoons are sprayed with only hobby-grade primers or directly with automotive filler primers (sans plastic primer), they exhibit the required surface texture that allows the automotive grade paints to adhere perfectly to the PP plastic. I do not know the science behind this, but if I had to hazard a guess, I'd say that the PP plastic is strong enough to withstand the corrosive nature of the solvents that exist in an automotive grade paint/filler primer.  

Testing Auto Paints on Mr.Fine Surfacer 1500, and Auto Filler Primer/Auto Plastic Primer

 Even with the eventual success I achieved when using automotive grade paints on PS plastic, it does come with two important caveats though. First, the use of a plastic primer followed by an auto filler primer creates a surface that is sometimes not 100% smooth to the naked eye. I've yet to consistently and easily create smoothly primed surfaces using this two-step process. Maybe I'll perfect the technique in the future, at least I hope so. Second, having to first apply a plastic primer before a filler primer creates unnecessary thickness to the final paint coat. More so when you consider that a final clear coat will need to be applied for optimal results.   

Success with auto paints on polystyrene plastic spoons requires specific steps

Success with auto paints on polypropylene plastic spoons requires less stringent steps

 So at the end of it all, the choice of whether to use auto paints and primers on scale model kit plastic boils down to one thing. Is color accuracy paramount in your hobby project? If the answer is yes, then go for it. I believe it's a risk worth taking. If not, then I say you're better off with using hobby primers and paints, which are more benign on plastic parts. Then again, PP plastic seems to work well with automotive grade paints and primers. But very few scale model kits I know of actually use PP plastic for its molded parts. Even for Aoshima kits, I'm not entirely sure if all or just some parts are PP plastic. I'll know for sure only when I use the automotive grade primers and paints on the parts itself. That's a challenge for the future. As for now, it's time to end this post. Stay safe, and be well! 

Girl's Rider [Work-in-Progress: Denim Jeans Part 2/2, plus Initial Leather Work] - 1/12 scale miniature figurine

 After a brief divergence into the world of car scale model kits, it's back to the miniature female figurine. (That is, at least until I can get my hands on some auto paints and primers to test out on plastic.) As eluded to in a previous post, the Girl's Rider miniature female figurine's denim jeans required more work especially in terms of texture and contrast. So I set about doing just that, in addition to starting initial work on the figurine's leather accessories such as her gloves (not shown in this post), belt and boots. Results of both can be seen in the photos shown below.

Girl's Rider work-in-progress: denim and leather (front view, black background)

In general, the second phase of the denim jeans painting process involved ...

... adding more texture to the jeans (in order to increase realism) without dulling the contrast ...

... as well as increasing contrast by brightening up highlights especially on the jeans wrinkles.  

Girl's Rider work-in-progress: denim and leather (back view, black background)

A secondary aim of doing further work on the denim jeans was ...

... to reduce overall glossiness of the jeans either via texture or a matt clear coat ...

... of which the former (i.e. painting more texture) was my method of choice.

Photos of denim and leather against a black background were shot with the Canon EOS 650D & Tamron 90mm macro lens; with settings at f/16 aperture; 1/60sec shutter speed; and ISO-1600

 So what did I do to the denim jeans in this second phase? Firstly, I painted denim texture onto areas of the jean which I believed to be a bit too bare and plain. A byproduct of this step was the further reduction of gloss levels in the denim jeans. Even so, there is a likelihood I may add a final clear matt coat to further dull the glossiness levels. Secondly, I brightened up the highlights especially on the wrinkles of the denim jeans, thus slightly improving the contrast.   

Girl's Rider work-in-progress: denim and leather (front view, white background)

While overall glossiness of denim jeans has been reduced somewhat ...

... there is a possibility any residual glossiness may be further dulled down ...

... with a clear flat coat to be applied at the final stage of the painting process.

Girl's Rider work-in-progress: denim and leather (back view, white background)

Another way the glossiness of the denim jeans is being dulled ...

... is via an optical illusion whereby the leather boots/belt are painted with a shinier texture ...

... thus relegating the denim jeans in terms of glossiness level compared to the leather.

Photos of denim and leather against a white background were shot with the Canon EOS 650D & Tamron 90mm macro lens; with settings at f/16 aperture; 1/60sec shutter speed; and ISO-1600

 Meanwhile work finally began on the figurine's leather accessories which comprise her riding gloves, boots, and belt. With the aim of painting a new, red leather look, I used a Vallejo Model Color paint recipe comprising 70.950 Black, 70.828 Wood Grain, 70.981 Orange Brown, and 70.847 Dark Sand. This color recipe was used in moderation, meaning the painting technique was executed in a way that de-emphasizes scratch and scuff marks, both of which are more numerous in old leather.   

 Everything's relative in that the denim jeans don't look as shiny next to the leather belt and boots. Although the jeans still look a tad too glossy for my liking, they look much less shinier when are seen together with the figurine's leather accessories. So much so that at first I thought I had made the leather too shiny as I was painting from memory and not based on actual reference photos. However when I did finally did the necessary research to find online images of branded, new (and presumably polished) leather boots, I found that they did indeed look very shiny. In fact they reflect light to such an extent that the leather texture becomes completely obscured by the reflected light.     

Girl's Rider work-in-progress: denim and leather (front view, azure background)

At first I thought I had made the leather boots look too shiny ...

... but upon further research I realized that polished leather boots ...

... have the exact same 'glossiness profile' that you see in the photos here.

Girl's Rider work-in-progress: denim and leather (back view, azure background)

In terms of work on the leather accessories like the gloves (not shown), belt, and boots ...

... I am currently in two minds as to whether to leave them as they are ...

... or add yet more leathery texture to them going forward.

Photos of denim and leather against an azure background were shot with the Canon EOS 650D & Tamron 90mm macro lens; with settings at f/16 aperture; 1/60sec shutter speed; and ISO-1600

 While I'm still at two minds whether to add more texture to the leather, there are other areas that need my attention. Specifically, the steel buckles on the belt and boots. Assuming I don't add any more texture to the leather pieces, then the accessories will be considered complete once the steel buckles are painted. Meanwhile, I'll be attempting the autopaint/primer on plastic test soon, in addition to the resurrection of two long neglected projects. One is the Star Wars Speeder Bike, which will be used in a vignette together with the Girl's Rider and Scout Trooper figurines. And two, is the Volkswagen Beetle, which I plan to complete first before starting a new car scale model kit project. So a lot to do. More importantly a newfound will to do them. So cheers. Stay safe, and be well.

First scale model kits bought in nearly a year

 If there is one thing the pandemic has taught me, well not so much taught as giving me a timely reminder that most miniature painters and scale modellers - yours truly included - have way more kits than time in which to complete them. Add economic concerns during the pandemic, and it was easy for me to take a step back from the acquisition side of the hobby to stay focused on working with what I already possess. But temptation to add to my collection has never truly left me. So with nearly a year into my self-imposed abstention, my will wavered and three scale model kits were acquired.      

My first new model kits in nearly a year - all of them are 1/24 scale Tamiya car kits

 One factor contributing to the new purchases was the 10% sale my local hobby store was offering. While it wasn't much, every little bit off helps in this wallet straining pandemic era. As you can see by now, the scale model car kits that caught my eye were Tamiya 1/24 scale versions of the Subaru BRZ, the Ford GT, and the Subaru Impreza used at the WRC (World Rally Championship) Rallye Monte Carlo 2005. You may have also noticed the trio of Tamiya scale model kits are in an iconic metallic blue. In fact, Tamiya recommends the LP-41 Mica Blue lacquer paint, which is a vibrant and deep shade of metallic blue. As luck would have it, I can't find any local hobby store with this color in stock. So none of the cars can be worked on anytime soon unless I find an alternative!  

Side box art showcasing all three Tamiya scale model kits namely ...

 For me, what makes a car brand attractive is that it has to have either a Rally, Formula One, and/or Endurance racing heritage. And of all of them, I feel that rallying is the most relatable motorsport seeing that rally cars are road legal cars based on mass production models affordable to the mass market. As such, it should be no surprise my all-time favorite cars are the Mitsubishi Lancer Evolution and the Subaru Impreza WRX STI, of which the former is sadly no longer in production. In real-life I drive a rebadged Mitsubishi Lancer (rebadged due to the country's car industry being protected from imports). And after more than 10 years, the family is contemplating getting a new car - specifically a subcompact crossover called the Subaru XV, which is technically a lifted Impreza hatchback. Like my cars, I tend to see people based on substance rather than style!   

... (from top to bottom) the Subaru BRZ, Ford GT, and Subaru Impreza WRC 2005

 First up in my latest scale model kit acquisition is the second generation Subaru BRZ coupe. It's powered by a 2.4-liter four-cylinder boxer engine that generates roughly 228 horsepower and a top speed of about 226 km/h. As Subaru's first rear-wheel drive sports car, the BRZ is a unique vehicle in Subaru's otherwise all-wheel-drive lineup that the Japanese company is famous for.   

Tamiya 1/24 scale Subaru BRZ (ZD8) car model kit

 Then there is the Ford GT, whose name is derived from the legendary Ford GT40. The latter is none other than the victor in a titanic battle between Ford and Ferrari during the 1966 24-hours of Le Mans. Based around a carbon fiber monocoque, the Ford GT can achieve a top speed of about 347 km/h on the back of its 647 horsepower 3.5-liter V6 engine. It's a supercar though, not a mass market one.

Tamiya 1/24 scale Ford GT car model kit

 Last but not least is yet another car from Subaru, this time it's a traditional all-wheel drive vehicle the company is more famous for. Fun Fact: the only other car company to use a boxer engine in this day and age is Porsche. Powered by a flat four-cylinder turbocharged 2-liter boxer engine, the Subaru Impreza WRC 2005 can achieve speeds of up to 257 km/h and generate up to 300 horsepower. It was the rally car driven by Petter Solberg in the Rallye Automobile de Monte-Carlo 2005.

Tamiya 1/24 scale Subaru Impreza WRC Monte Carlo 2005 car model kit

 All these vehicles will be build up and painted in the future either for my own collection (aka display pieces to promote commission work), or be put up for sale as fully completed projects. At the moment, I'm unable to source the iconic metallic blue lacquer paint from nearby local hobby shops. So what I'm going to do is try out automotive spray paints instead. If I can get my hands on these alternative paints then I'll be sure test them out and let you know the results in an upcoming post. On that note, I shall leave you with the words of James May ... peace and love, brothers and sisters!