1970 Chevelle undercarriage(chassis) factory primer color?

[crowe-t]

Does anyone know what color primer was used on the undercarriage(floor) of a 1970 Chevelle?

I know the chassis rails are black.  

Is the primer light gray, dark gray, red...?

Edited December 13, 2017 by crowe-t

[Classicgas]

Typically they were light gray, but the factory was notorious for using whatever was available.

[Snake45]

30 minutes ago, Classicgas said:

Typically they were light gray, but the factory was notorious for using whatever was available.

That's my impression, too. For model use, I'd go with whatever medium primer gray you have on hand. And remember, body color overspray on the primer, but NOT on the frame. 

[crowe-t]

I've read that the primer color depends on where the cars were built.  It could be red or gray.  

I'd still like to see some pictures of this.  As of now I'm going with the gray primer.  I kind of like the look of the gray primer more anyway since I'm painting it Champagne Gold.  I think the Champagne Gold overspray will look better on the gray primer.

[crowe-t]

I found pictures of the underside floor pan of a 1970 Chevelle that was restored to it's exact look when new.  

The green body color seems to be only on the floors and the cross braces have red primer on them.  I was expecting to see the green body color overspray on the sides.  

Has anyone seen this before?

[crowe-t]

This 1970 Chevelle's under side floors are red primer with the body color overspray.  Both this Chevelle and the one in the previous post were done by the same restoration shop.

 

[crowe-t]

I got this picture from another restoration shop.  The cars built in Atlanta had gray primer with a slight hint of green in it.  

I think for my current build I might go with the red oxide primer.  

[Snake45]

Interesting. I always think of the red primer as more of a Ford thing, but I guess these are tendencies or likelihoods rather than absolutes.

[Model Carnage]

The red and green floorpan is totally wrong. The one showing 90% grey primer underneath is wrong. Restorers who have never been inside an automobile factory IMAGINE that bodies came out of the paint shop with lots of primer showing underneath. In reality, GM vehicles of the 1960s right up through the 1990s have pretty good topcoat coverage underneath. Even the car bodies painted by robots. People who been under a lot of GM cars and light trucks know this. When the bodies were painted manually, the guys intentionally blew color under the body except on Corvettes. The paint bots were programmed to do the same. So GM cars & light trucks from the 1960s-up should have mostly body color underneath with the exception of the top of the transmission/driveshaft tunnel and places on unibody cars where the 'frame rails' threw a shadow.

BTW, the half painted bellhousing and the unpainted bellhousing on the other is wrong. Bellhousings from iron-block Chevy engines at least from the mid-1960s-up were completely painted engine color, even the transmission face, while the bellhousing was attached to the engine.  Again, ask someone who has lived working on original cars. Incorrectly restoring a car like these pretend experts does not change history.

 

 

 

 

Edited December 14, 2017 by Model Carnage

[crowe-t]

13 minutes ago, Model Carnage said:

The red and green floorpan is totally wrong. The one showing 90% grey primer underneath is wrong. Restorers who have never been inside an automobile factory IMAGINE that bodies came out of the paint shop with lots of primer showing underneath. In reality, GM vehicles of the 1960s right up through the 1990s have pretty good topcoat coverage underneath. Even the car bodies painted by robots. People who been under a lot of GM cars and light trucks know this. When the bodies were painted manually, the guys intentionally blew color under the body except on Corvettes. The paint bots were programmed to do the same. So GM cars & light trucks from the 1960s-up should have mostly body color underneath with the exception of the top of the transmission/driveshaft tunnel and places on unibody cars where the 'frame rails' threw a shadow.

BTW, the half painted bellhousing and the unpainted bellhousing on the other is wrong. Bellhousings from iron-block Chevy engines at least from the mid-1960s-up were completely painted engine color, even the transmission face, while the bellhousing was attached to the engine.  Again, ask someone who has lived working on original cars. Incorrectly restoring a car like these pretend experts does not change history.

 

 

 

 

These pictures below are correct?

There seems to be more of the blue body color over the red oxide primer and the bell housing is painted the engine color.

Edited December 14, 2017 by crowe-t

[Model Carnage]

Those pics are from a 1968-72 GM A-body. The all-orange bellhousing is correct. I say there should be a lot more body color over that red primer. Should be almost completely body color except the transmission tunnel and along the rocker panel sills where the sill threw a shadow.  Somebody went to great pains to blow black paint on the backside of the rocker sills on the black & grey floorpan. What were they thinking? Self-proclaimed and clueless experts. 

The primer color was chosen by an engineer in each individual plant. I've seen a lot of dark grey, even under white topcoat. There were 2 painters in the paint booth,  each blowing acrylic lacquer on their side of the body as is moved thru the paint booth.  They intentionally blew paint under the body from both sides and behind.  Even the floorpans under the carpet have a lot of body color on them. Oh, it's thin coverage but you see hardly any primer. So as a rule, GM cars and light trucks of the era had pretty good BODY COLOR coverage underneath. Even after they started painting them with robots. The firewalls got painted last. A big piece of plastic draped over the body around the cowl and the firewall painted semigloss black.  The bottom of the firewall not masked so the black fades into the underbody color down there. The black firewalls ended about the same time they switched from lacquer to 2-stage urethane in the late 1980s. 

[Mike Chernecki]

My '70 Chevelle has a grey undercarriage. All original and has not been repainted.

Edited December 14, 2017 by Mike Chernecki

[crowe-t]

54 minutes ago, Mike Chernecki said:

My '70 Chevelle has a grey undercarriage. All original and has not been repainted.

Do you have a picture of your '70 Chevelle's undercarriage?

[Mike Chernecki]

36 minutes ago, crowe-t said:

Do you have a picture of your '70 Chevelle's undercarriage?

Somewhere, I would need to look for them. 

[gtx6970]

On 12/13/2017 at 11:12 PM, crowe-t said:

I've read that the primer color depends on where the cars were built.  It could be red or gray.  

I'd still like to see some pictures of this.  As of now I'm going with the gray primer.  I kind of like the look of the gray primer more anyway since I'm painting it Champagne Gold.  I think the Champagne Gold overspray will look better on the gray primer.

If it in fact applies to GM cars I have no idea.

 

But I know for a fact Mopars of the same era were grey ,,,EXCEPT LA plant built cars. They were black

[1972coronet]

I , too , am thinking : Plant variations . Local suppliers would supply different primers ; the aforementioned Chrysler Los Angeles (City of Commerce) Assembly Plant employing black vs. the typical grey . Makes me wonder if the General Motors Los Angeles (South Gate) Plant also used different coloured primers ? Granted , that was a B-Body facility (think : full-sized cars) , so that ostensibly wouldn't affect the A-bodies . Maybe the Fremont plant used red oxide ?

[espo]

This is an interesting topic and I think the only way to know for sure would be to find phots taken when these cars were new. Unfortunately most of the undercarriage pictures I have ever seen from that era were in black and white so it would be difficult at best to know for sure. The photos shown here are great examples of what I've seen from many professional restoration shops. That said they always look just a little to perfect to my eye. I wonder if the shops are basing their painting based on what they found in their initial cleaning of the body or what. My contention is that when these cars were coming down the assembly line they were just the next build as they reached each station on the line. The people on the line were responsible for a set task and had a limited time to do it. As long as the shinny top side looked good that was good enough. They really weren't considered as anything special at the time. As mentioned, in the paint booth you would have at least two different people on opposite sides spraying paint. That in it's self would mean some inconsistency in paint coverage. So now say one of them has a cold and sneezes. That side has a little less coverage than the other side. My feeling is that the restoration shops are striving for what they feel is the perfect as assembled look and in fact the look is too perfect and not truly reflective of what these cars looked like when new.  So I would just paint your model they way it looks best to you and have fun doing it.   

[Snake45]

This thread perfectly illustrates why many of us just paint our whole chassis semigloss/matte/flat black and get on with our lives. 

[Classicgas]

From a friend of mine that is very knowledgeable about GM cars of the 60's and 70's.

Chassis would be semi gloss black. Floor pans would be primerish/steel 

[crowe-t]

Did the body color affect what color primer was used or was the primer color dependent on what plant they were built in?

I'm painting an AMT 1970 Chevelle in Autumn Gold code 58 which is a 1970 Chevelle color.  Would gold have a gray primer or red?

[Classicgas]

It would depend on the plant and what primer was on hand.

[crowe-t]

3 hours ago, Classicgas said:

It would depend on the plant and what primer was on hand.

So the body color had no effect on what color primer was used?

[R.D.F.]

On 12/13/2017 at 5:17 PM, crowe-t said:

Does anyone know what color primer was used on the undercarriage(floor) of a 1970 Chevelle?

I know the chassis rails are black.  

Is the primer light gray, dark gray, red...?

On my real 70 when I bought it brand new was black.

Here's something to read:

https://www.chevelles.com/forums/12-body-shop/372047-correct-color-floor-pan-1970-chevelle.html

Edited February 26, 2019 by R.D.F.

[crowe-t]

Now I'm trying to figure out what color primer should be under Autumn Gold. 

[Ron Hamilton]

I have looked under several unrestored Pontiacs of the period at a restoration shop. The floors were satin black, with body color overspray, where the width of overspray varied from plant to plant. When I went to the Baltimore Plant in 1970, I saw Chevrolet Chevelles and Monte Carlos that were painted that way.