Car undercarriage

[scalemodelworld]

After getting back into car builds, I've been trying to spice up the underside a bit. I usually just paint them semi-gloss black, but it feels like a "Yeah, whatever" colour. Not being a car enthusiast in real life, I don't know what colour I should be painting my undercarriage.

Should I just stick with semi-gloss black, or maybe metallic black?

And for more colourful detail, what about the steering components? Instructions always just say satin black, but again I find that boring. Any tips would be great.

[Erik Smith]

If you are going for a factory stock model, you will have to research each car specifically, as there are many variations to finishes. I like to paint the main undercarriage flat black. Then I use rub and buff and very lightly highlight raised areas. I then paint the other main parts (rear end, etc) a different sheen of black or metalizer. I also like to pick out small details and bolts in different colors. Just breaking up the monotony of black helps a lot.

Chances are, you will be the only one to notice it much. Most people look at the top of a car and don't have much concern for the underside - I still think its fun to detail, though.

Ill see if I can find a picture or two to post.

Here is one:

This one was just done with different metalizers:

And at the other end, here is a weathered chassis:

Edited January 9, 2013 by Erik Smith

[Tom Geiger]

As you can see, I like chassis detail. Funny thing, as I went though the albums of my built models, I didn't have chassis shots of many of them... and I went to a lot of work on those. The above chassis is on an AMT '55 Chevy pickup and was done to represent a working vehicle. Note that every vehicle has some degree of dirt and wear on the chassis. Even new cars on the lot have the start of toning on the exhaust system and rust on bare bolts. I also like to do some weathering, anything from a light dusting for a new car to bring out detail highlights like Erik did above.

For varying dark tones, collect different brands of black, semi gloss black, flat black etc. You'll find that when you put them next to one another, they vary in color and effect. You can also use Testors Metalizers, I like them without the fixative coat. There are also dark grays that work on chassis. I like the Testors Euro dark gray (I believe this once was called Panzer gray) because it's very dark, almost black. I've used this for bottom floor pans. You can also add different tones by using Testor Dullcote or semi gloss over any of the above. I also like the Poly S / Floquil weathering set that includes colors like "mud", "rust", "grimy black" and "dust". One brand of these is acrylic (preferred by me) and one is more enamel. The acrylic is easier to blend with water for weathering.

I also like to use earth tone pastel chalks. I bought a set at a hobby shop that is just the earth tones and that $10 box has lasted forever. I leave the sticks in the box and sand the sides of them to get dust to either brush on the model or to work onto the model with Testors Dullcote.

One suggestion I have is RESEARCH! I regularly go to eBay Motors to collect detail photos from the car ads. Some sellers post 20-50 photos and I'll often save an entire set on vehicles I'm interested in. Some put the cars on a lift and shoot several shots of the chassis. That's where you'll get the detail you need to build a killer chassis.

Here's an example of a reference shot. Not the greatest picture but what I had on hand. This is actually the Deora show car.

Even the parts photos are useful. What's the underside of a used tranny look like? Here ya go!

Hope this helps!

[scalemodelworld]

Thanks for the tips. I still don't own an airbrush, so things like highlighting and using the pastel dust seem a little out of reach for me. I do like the concept of colouring bolts and features, and I've tried doing that on my current model - a 1970 Mustang Boss.

[southpier]

http://straightlinemodeler.org/paintblack.html

you don't need an airbrush. develop your "dry brushing" skills.

http://www.finescale.com/~/media/import/files/pdf/1/0/e/dry-brushing.pdf

dry pigments are very forgiving. don't let the pictures in the magazines intimidate you! and when you get something you like, spray it with an afixative (Testor's Dullcoat is good - someone will come along with one better).

http://www.missing-lynx.com/rare_world/rw05.htm

and rust is good, yes?

http://www.rustall.com/

Edited January 10, 2013 by southpier

[Ace-Garageguy]

If you care at all about accuracy, research is critical. Google image searches can return many many photos of the info you want.

A fair generalization is that many full-frame vehicles have semi-gloss black frames, with the floor portions, being part of the body shell, painted body color. This holds true for older cars as well as recent pickups. Unibody cars often have the underside painted body color, again as it's a welded part of the body structure, and in more recent cost-conscious times, to save paint the undersides of the unibody shell will show a red, grey, black or green-gray primer, with overspray of the main body color around the edges.

[crazyjim]

A FAST friend turned me on to Rustoleum Texture finish paint (rattle can). I've been using three of the colors (off white, tan, black) for chassis paint. The stuff is almost like zolotone with several different colors in the paint. It may not be accurate, but I don't care because I like the paint.

[Tom Geiger]

. I still don't own an airbrush, so things like highlighting and using the pastel dust seem a little out of reach for me.

I don't use an airbrush. All my detail and weathering is done with rattle cans and brush type techniques. The detailing I do with pastel dust and Testors Dullcote paint is all by brush. It's kind of like doing water color painting.

[scalemodelworld]

Wow, thanks everyone. I'd heard of dry brushing, but like all "new" techniques, it looked like something I could never do. I'll get researching and by the looks of things, I'm about to improve my finishing!

[southpier]

there's 15 articles between the Tip and the Q&A departments here on the forum. do a search for "drybrushing" and it'll take you there

[Guest]

I never paint my chassis' flat black or semi gloss black anymore unless it's a curbside build. I used to, but like you said, it's a "yeah whatever" type deal. Like Bill said, do some research and see how the real cars look underneath. You'll be hard pressed to find a real car that has a flat/semi gloss black floor pan unless it's one that has been undercoated. Most cars have the chassis primered and sealed with body overspray on the edges. Newer cars have practically no overspray on the floor pans. It also depends on what type of build you're doing. Hot rods,street machines and customs usually have the floor pans painted body color. Stock or semi stock will have the primered chassis with overspray on the edges and the chassis (if separate) a semi gloss black.

Here's a few examples

Even though this was a curbside build, I decided to detail paint it

And for a comparison. Here's an old build that I painted flat black.

[Erik Smith]

You'll be hard pressed to find a real car that has a flat/semi gloss black floor pan unless it's one that has been undercoated. Most cars have the chassis primered and sealed with body overspray on the edges.

Actually, it is quite common to have a black undercarriage. Google "<insert car name here> undercarriage" and you will get results, most of which show a semi gloss undercarriage. I do both, but it's not hard to find black.

Camaro:

Charger:

Some other car:

56 Ford:

[Tom Geiger]

In the latest Scale Auto (Feb issue) there's a Letter To The Editor from Marty Kirk (I think I've seen that name on the board here) about over spray on chassis. He said that very few cars had over spray on the chassis from the factory. He says that we're taking that documentation from over restored cars, and that today's cars don't have it because the paint is controlled by robots not to waste valuable paint. See the pictures of Camaro and Challenger under carriages Erik posted right above here.

Quite frankly I've never seen over spray on any of my cars other than a Maaco repaint. Most of my '60s Valiants and Barracudas had the factory undercoat, which was a thick wrinkled finish in a dark green to brown color. The ones that didn't have it also had massive floor rust making me believe those left the factory in bare metal. I believe a lot of older cars had bare metal inside doors and panels too. The dealer undercoat cars are basically black spray can undercoat. My Dodge Caravan has a metal color floor pan, with factory undercoat in some key places. My Geo Tracker has the entire underside done in a heavy yellow plastic like coating.

I don't believe any US manufacturer of consumer grade vehicles concentrated much on the underside appearance.

[scalemodelworld]

Thanks to everyone for all the advice. I have a friend from work who's a bit of an expert on dry-brushing, so I'll get in touch with him in a few weeks and maybe get some lessons.

In the meantime, I decided to go with Flat Black as the main colour, with Metallic Black highlights, not to mention the Aluminium exhaust.

I know it's not awesome, but I'd be interested to hear what people think.

[David G.]

Looks good! Subtlety is the key, minor variations in tone and color can make a big difference.

You may want to add a bit of dust and dirt in the form of pastels- shades of black, tan and grey.

I built this Mustang a few years ago and weathered it as if it had seen just a few years of regular service. I used paint washes and artist's pastels.

You're off to a good start! Research and look at pictures online to fill your mind with the natural patterns of dirt and rust that occur as chassis age and soon this will be second nature to you.

David G.

[Art Anderson]

If you care at all about accuracy, research is critical. Google image searches can return many many photos of the info you want.

A fair generalization is that many full-frame vehicles have semi-gloss black frames, with the floor portions, being part of the body shell, painted body color. This holds true for older cars as well as recent pickups. Unibody cars often have the underside painted body color, again as it's a welded part of the body structure, and in more recent cost-conscious times, to save paint the undersides of the unibody shell will show a red, grey, black or green-gray primer, with overspray of the main body color around the edges.

Actually,

This generalization works only for cars manufactured in the robotic-painting era. In the decades before our modern era, car bodies for "body on frame" construction were painted by humans, using hand-held spray guns, the car bodies almost universally being moved into the spray painting booths in the factories on steel carts, the bodies themselves being positioned perhaps a foot or so above floor level. Depending on the car, and the simplicity (or complexity!) of it's styling, a crew of 2 or 3 painters did the work of adding the body color. Of course, prior to this step, from at least the middle 1950's forward, newly welded up car bodies were dipped in vats of primer (and by the 60's, rust inhibitors--such as they worked) first, baked dry, and then sanded smooth. This setup precluded painting the undersides of car bodies with color, but the painters, in "ducking down" to coat the underside of rocker panels, and when painting the firewall, did leave a swath of overspray on the outer sides and across the front of, the floorboards.

Automobile frames pretty much have been painted a semi-gloss black (and a cheap paint at that) before hitting the assembly line, as were other painted components, which meant that bolts and nuts (along with little brackets and clips for holding wiring, brake and fuel lines, and the like were raw metal (generally cadmium plated), and of course, gas tanks were galvanized sheet steel, with unpainted, raw steel exhaust systems.

The above painting process was, I believe, pretty much the case with unibody cars as well, certainly well into the 1970's (it sure was the case with my brand-new 1970 Barracuda!). One thing about unibody cars however: Depending upon whether or not subframing was welded onto the body shell (AMC, along with Chrysler and Ford's Falcon and Mustang) or bolted on (front subframing for certainly 1967-later Camaro's and Firebirds, along with the Nova). Bolt on front subframes more often than not were painted black, where welded on subframing generally got the same color as the outer surfaces of the body shell.

The first car I ever owned that had its undersides painted body color was my 1986 Plymouth Voyager, and I would suspect that this is very much the case today.

Art