How To: Weathering an Athearn Southern Pacific GP40x

[tom mann]

I’ve always liked this model mainly due to the interesting experimental HT-B trucks. The real GP40x is quite uncommon with only 23 produced (and only 10 had HT-B trucks), but fortunately there are a few photos on the Internet including nicely weathered SP models.  Fortunately, we can weather the same number:


The end result will look something like this:






Over the next day I'll post some in-progress photos and some helpful tricks and hints.  Stand by!

[tom mann]

This is how the model looks out of the box. Athearn does a nice job detailing these, and the build quality is very nice.



I've removed the couplers, since I'll replace them with most excellent Sergents.

First step is to fade everything using a light tan color, essentially a glaze that transform the toy-like plastic grey.  You don't want to overdo it, but you can exaggerate slightly since subsequent steps will involve black washes to bring out detail and shade the gray.  In this case, I used Polly Scale Aged White.  Don’t use a cool white, because you’ll end up with a model that looks like it is covered in frost, and the red nose will look pink.  There is already some nice information about how to thin paint for an optimal glaze in other threads.



Note: this photo was taken using the same environment and camera's color temperature (5000k)

[tom mann]

Paint the trucks next.  I decided that a warm medium brown would look best, so I mixed some Polly Scale Dirt with Rust (1:1) and sprayed this on without too much thinner (since I wanted a slight texture).  If I were using Vallejo paints, I would use Earth and Rust.  Another option is M. Graham’s Transparent Oxide Orange as it is pretty close to Rust.

What about the wheels? You can disassemble them and paint the wheel surface.  I've done this and used an automotive primer for maximum adhesion.  Or, you can paint them still assembled. This is what I like now, since I have a finer airbrush and I can use Vallejo's primers on the wheel first.   I run the engine around on a track to change the position of the wheel so it is not masked by the truck.

I also used a little bit of the same Dirt/Rust mixture along the bottom frame and on the top.



At this point, we don't need the airbrush anymore! 

[Scottl]

I love watching this unfold.  Even at this early stage, the results are excellent. 

[central.vermont]

Tom,
You do such wonderful work but there is one thing that really bothers me and it has nothing to do with what you have done. It's an Athearn complaint that I have and it pertains to the lights. They are the most ugly things about their models. I mean look at the way they stick out like bullets!!!  They make this nice model but are still stuck with 70's tooling on the lights.  Why don't they retool these damn things! It really sticks out........literally.

Well keep up the great work, that was just a rant I had to let out. 

Jon          Stepping down from the soap box.

I’ve always liked this model mainly due to the interesting experimental HT-B trucks. The real GP40x is quite uncommon with only 23 produced (and only 10 had HT-B trucks), but fortunately there are a few photos on the Internet including nicely weathered SP models.  Fortunately, we can weather the same number:

Over the next day I'll post some in-progress photos and some helpful tricks and hints.  Stand by!

[tom mann]

I mean look at the way they stick out like bullets!!! 

Yep, the number one request is for Athearn to start using LEDs!

[Smike]

This is a thread stuff with awesome. This will help me break down and start spraying some of my $100 n scale engine...

[tom mann]

Let anything you've painted with the airbrush dry overnight.

I use about a 1/3" flat synthetic brush to apply glazes (or washes).  I like to match up the width of the brush to features of what I'm painting - hood doors in this case.  In this example, I'm using Winsor & Newton Water Soluble Oils that can be thinned with water and have no odors.

I start with Burnt Umber on the trucks and fuel tank. Mix a little paint with some water; the mix should resemble a thin soup - you really are essentially just coloring water.  What you've created is a "glaze".  Apply with the brush, working top down.



Make sure the glaze is thick enough to settle into crevices, like the truck details:


For the subtle streaking on the fuel tank, dab the corner/edge of your brush (already wet with the glaze mixture) into the paint and collect a pinhead-sized amount. This will leave more paint pigment on one edge as you work the brush from the top of the tank to the bottom.


Take care with the oils.  If you work too aggressively, the oils will remove some of the airbrushed layer (note:  this may be an effect you want in some instances). 

Next, I use Ivory Black on the body, applied in the same way.  This gets the color fairly close to the actual locomotive example.



The oils will take some time to dry, so anything can be corrected later on.  This is a huge advantage over acrylics.

[Scottl]

Do you have a preference for the manufacturer of the oils you use?

[tom mann]

Do you have a preference for the manufacturer of the oils you use?

I wrote Liquitex above, but I really mean Winsor & Newton.  The colors work just fine to simulate different types of rust.  I can't say I tried other brands.  W&S was the first to market with water solubles and I purchased my tubes 10 years ago when I think there was no other choice!

[Scottl]

Thanks.  I could not find Liquitex oils at Michael's recently, that clarifies it.  The oils are very effective to my eye.

[tom mann]

Coming up tomorrow:  how to use oil paints to get that texture effect on the trucks!

[ednadolski]

Great thread Tom.  I'm really enjoying the step-by-step treatment, thanks for taking the time to do this.   

Ed

[Smike]

Tom keep it up, solid gold here. One question on the oil wash, when applying over large area's on n scale how's the effect?  I find that on n scale up close I've never been happy with my washes, (mostly uneven) but I'll admit I never used water soluble oils for this.

Thanks!

[davefoxx]

Good stuff, Tom.  Thanks for documenting this, so we can follow along.  I'm looking forward to seeing how you modeled the "char" on the long hood and lettering.

DFF