I want to paint it yellow

[Kentuckian]

This is the Kato steeple cab which is cast in orange plastic. I want to turn it UPish yellow, or safety yellow. What is the most efficient way to do this? I haven’t had much luck with coverage using acrylic yellows in the past. I do have an airbrush.

[johnb]

I would use a white primer

[mplsjct]

Agreed, white or light gray primer first, then apply the yellow

I have been using acrylics for over 20 years, couldn’t stand the smell of Floquil and Scalecoat, but that is another story.

[bbussey]

Decant a spray can of Krylon or Rustoleum yellow of your choice, then airbrush it.  Make sure it's one that is safe for plastics.  Most of the paints of both brands now have primer in it and it will cover.  Plus, the paint is thin and it leaves a beautiful finish.

[nkalanaga]

Scalecoat yellow will probably cover it, if you want to use a "traditional" paint, and would be easier than trying to get paint out of a spray can.  They make a primer, or you can use my favorite for undercoating yellow, UP Hopper Gray, a very light gray.

[bbussey]

This is decanted Rustoleum “Sun Yellow” which is a pale yellow airbrushed over Mr Surfacer 1200 oxide red primer. It covered in one coat.



This is decanted Rustoleum “Caterpillar Yellow” airbrushed over Mr Surfacer 1000 gray primer. It also covered in one coat. Note that it also covered the blue painter's masking tape that the radiators are adhered to on the paint stick with no bleed-through.



It’s not difficult to decant paint. Just need a plastic straw cut in half with a large enough diameter to cover the spray nozzle and a paint bottle, then let it de-gas for a day.

[thomasjmdavis]

If you want to stay with acrylics or waterborne paints, I have had good success with Badger's primer that they market under the name Stynylrez (which I'm told is a contraction of styrene-vinyl-resin - the various things it is designed to stick to, although I've also found it sticks better to brass and nickel silver than any other acrylic product I've tried).  They refer to it as an acrylic polyurethane, and it dries to a hard shell.  And it is available in bottles from 2oz to a quart.
https://badgerairbrush.com/Stynylrez.asp

I've been buying it from a company called USAAirbrush, which carries Badger's whole line of airbrushes and paints, and is branching out into other brands.  The one caveat is that, like the rest of the world, they are experiencing occasional supply chain issues, and so you may want to call to be sure they have what you want in stock (my most recent couple orders took several weeks as they waited for restock on some of the paints I wanted).  The upside is that they run frequent sales and specials, and their pricing on paint is always at a healthy discount. And the paint is always "fresh", at least in my experience.
https://usaairbrushsupply.com/

[Doc Frankenfield]

going way back to my automotive mural / custom paint days:
I used to use rattle can colors sprayed into a cup and then sprayed from the airbrush.
Back then my weapon of choice was Krylon but that product has been taken over and deleted by Rust-oleum.
 You can probably get a fair match at an Auto parts store and us that technique.

[Frank Amato]

If you want to stay with acrylics or waterborne paints, I have had good success with Badger's primer that they market under the name Stynylrez 

This is my go-to primer, using my trusty old Paasche H airbrush at 20 PSI!

  Frank

[thomasjmdavis]

Back then my weapon of choice was Krylon but that product has been taken over and deleted by Rust-oleum.
 

Krylon is owned by Sherwin Williams. And by all accounts, remains one of the largest manufacturers of aerosol paints in the world. 

https://corporate.sherwin-williams.com/our-company/brands.html (scroll down)

[peteski]

Krylon is owned by Sherwin Williams. And by all accounts, remains one of the largest manufacturers of aerosol paints in the world. 

https://corporate.sherwin-williams.com/our-company/brands.html (scroll down)

So Rust-Oleum then is owned by RPM (the other large manufacturers of paints that also has/had many of the hobby lines of paint).

[bbussey]

Krylon is owned by Sherwin Williams. And by all accounts, remains one of the largest manufacturers of aerosol paints in the world. 

https://corporate.sherwin-williams.com/our-company/brands.html (scroll down)

I think he meant that Rustoleum has replaced Krylon as his preference. I like Rustoleum also, a lot. While it blows out of the spray can like an open fire hydrant, it goes on smooth as glass from an airbrush. It’s super-thin and doesn’t obscure any model detail.

[thomasjmdavis]

I think he meant that Rustoleum has replaced Krylon as his preference. I like Rustoleum also, a lot. While it blows out of the spray can like an open fire hydrant, it goes on smooth as glass from an airbrush. It’s super-thin and doesn’t obscure any model detail.

OK, sorry if I misinterpreted.  It does make sense that Rustoleum would work better as an airbrush paint, since Krylon sets up so fast that it would gum up an airbrush if you took 30 seconds between sprays.

[bbussey]

I've been using it for non-railroad-specific colors for a few months now.  Cleans up with acetone.  No fuss, other than having to decant it.  The Caterpillar yellow was my first experience with it, and I was stunned at how thin the paint is and how thoroughly it covers with a single coat.

[robert3985]

One of the problems with spraying yellow over yellow/orange/red plastic is that the model retains its translucent look...because it IS translucent.  I have a bunch of old GoldenWest UP CA-3/CA-4 caboose models (which were the foundation of the Centralia Car Shops/Intermountain CA-3/CA-4 UP caboose line) that were molded in semi-translucent yellow plastic.  MTL's "Wood cabooses" are also molded in yellow plastic for their UP Armour Yellow painted ones, and are semi-translucent.  Early Intermountain PFE reefer kits had the same problem, with reefer orange over a translucent orange plastic body.

Sooo...I prime any model I'm going to paint with yellow paint with flat aluminum first...mainly because it's more opaque than mere "primer".

The most opaque Armour Yellow I've used (also the most accurate color) is Scalecoate II's "UP Yellow", which is really great in my Paasche VL airbrushes, and cleans up easily with paint thinner.

The other Armour Yellow that I like, and sometimes use if I'm in a hurry, is True-Color Armour Yellow...which cleans up easily with Acetone.  I spray it full strength at 25psi with a #2 tip in my Paasche VL as per True-Color's recommendations.

These two brands are what I'm using for my custom paint jobs now, weathering with my ample supply of Pollyscale weathering colors. 

For decal-sealing gloss and semi-gloss over the decals, I'm using rattle-can Tamiya paint.

For Flat finish over decals, I'm still using Dullcote, which I have a good stock of. I don't use it much, preferring a glossy or semi-glossy finish on my motive power.

Photo (1) - Here's a photo of one of my Goldenwest Models superdetailing projects using flat aluminum as my primer, then airbrushing Scalecoat II for my Armour Yellow, Mineral Red and Loco Black...nice, opaque look with the yellow.


Cheerio!
Bob Gilmore