CRG Discussion Forum

Camaro Research Group Discussion => Originality => Topic started by: DavidS on January 06, 2012, 02:14:52 AM

Title: GM Heritage Center Documentation / Underbody color
Post by: DavidS on January 06, 2012, 02:14:52 AM
I am not sure if this info has been posted but these documents have a lot of GREAT info:

1967 http://gmheritagecenter.com/gm-heritage-archive/docs/Camaro/1967-Chevrolet-Camaro.pdf  (http://gmheritagecenter.com/gm-heritage-archive/docs/Camaro/1967-Chevrolet-Camaro.pdf)

1968 http://gmheritagecenter.com/gm-heritage-archive/docs/Camaro/1968-Chevrolet-Camaro.pdf  (http://gmheritagecenter.com/gm-heritage-archive/docs/Camaro/1968-Chevrolet-Camaro.pdf)

1969 http://gmheritagecenter.com/gm-heritage-archive/docs/Camaro/1969-Chevrolet-Camaro.pdf  (http://gmheritagecenter.com/gm-heritage-archive/docs/Camaro/1969-Chevrolet-Camaro.pdf)

For a long time, I have been curious about what color the underside of a 1969 Camaro should be.  There were quite a few postings that the color black on the underside of a Norwood car is the stuff of showcars.  After reading page 49 (as labeled on the page) "Exterior Paint Process", I would tend to agree that original undersides were primer color.
Title: Re: GM Heritage Center Documentation
Post by: 69Z28-RS on January 06, 2012, 05:31:21 AM
underside seems to be primer with areas of 'body color' overspray, as they sprayed the lower portions of the car body the underside got some body color..
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 06, 2012, 11:58:14 AM
Agreed.

I have a 69 Z/28 being restored and there were a few sections that had been repainted but it never had a complete repaint.  Here is the underside:

(http://img.photobucket.com/albums/v239/pratt1/z28/2011-09-27_09-52-43_356.jpg)

However, for judging, my understanding is that it should be black and not primer color.

Title: Re: GM Heritage Center Documentation
Post by: lakeholme on January 06, 2012, 01:20:23 PM
Especially the AMA charts. Same as the snail mail package you could request and same poor quality on a few pages, but it's great to have them downloadable. Thanks for sharing!
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 06, 2012, 03:57:10 PM
The question of what color to paint the underbody is not a trivial one for me.  My hope is to have the Z/28 as a judged trailer queen for a few years and then use the car for local driving and car show.  I am trying to have it restored as correctly as possible.  But if there is a deduction of points due to the underside not being black then I am not sure what to do  ???  ???  ???

The car will probably be ready for paint in a few weeks.

I have read through the GM info:
------------------------------------------------------------------------------------------
EXTERIOR PAINT PROCESS

1. RUSTPROOFING.  Assembled car bodies are chemically sprayed to clean and etch the metal surfaces for corrosion resistance and paint adhesion.  Unassembled sheet metal parts follow the same process.

2.  BODY AND SHEET METAL PRIMERS.  Four corrosion resistant primers, specially formulated are had sprayed on the body in areas where rust might develop.  Lower areas considered especially vulnerable are coated with another rust inhibiting compound.

3.  PRIMER COAT is applied to all outside and inside surfaces of front fenders and hoods.  The parts are mechanically dipped or flow-coated to insure coating in all seams and secluded areas, and baked at 390 degrees F for 30 minutes.  A coat of sealer is then applied by hand spray to all surfaces requiring another coat of lacquer.

4.  FLASH PRIMER AND PRIMER-SURFACER COATS.  An air-dry flash primer coat is hand sprayed on surfaces below the body belt line.  Then a gray primer-surfacer coat is hand sprayed on all outside surfaces of the body and oven baked for 45 minutes at 285 degrees F.

5.  INITIAL SANDING.  Power wet sanding, followed by hand sanding, is done on all body surfaces requiring lacquering.  This insures a smooth surface for the lacquer finish.  To remove the water, the body is wiped and run through an infra-red oven.

6.  LACQUERING.  Three coats of acrylic lacquer are spread on the exterior surfaces of the body and sheet metal parts to build up a finish of the required thickness for each color.

7.  INITIAL BAKING………….etc through step 11.
Title: Re: GM Heritage Center Documentation
Post by: JohnZ on January 06, 2012, 07:42:41 PM
<<The question of what color to paint the underbody is not a trivial one for me.  My hope is to have the Z/28 as a judged trailer queen for a few years and then use the car for local driving and car show.  I am trying to have it restored as correctly as possible.  But if there is a deduction of points due to the underside not being black then I am not sure what to do >>     



Have you read the Fisher Body Paint Shop portion of the First-Generation Camaro Assembly Process Report? Painting the underbody black is a typical restoration mistake.

http://www.camaros.org/assemblyprocess.shtml
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 06, 2012, 07:59:33 PM
Have you read the Fisher Body Paint Shop portion of the First-Generation Camaro Assembly Process Report? Painting the underbody black is a typical restoration mistake.

http://www.camaros.org/assemblyprocess.shtml

I did read that John and that's why I started researching this.  I believe you are absolutely correct.

What is baffling is that it does not seem to be just a restoration mistake, but it is a widespread held belief that they should be black.  From very high end restoration places to judges.  However, it is documented both through you and through GM that the underside is  primer.  At that point, it's not a subjective issue.  It is GM documented, historian documented, and at least on my car is proven out by physical evidence.
Title: Re: GM Heritage Center Documentation
Post by: Mark on January 07, 2012, 01:38:30 PM
Coverage of the primer is also different from one plant to another, the bodys at norwood sat on trucks that rolled along tracks on the floor with the bottom of the body about 18" off the floor, while the bodys at LA hung from a ceiling mounted track which allowed more access to the underneath portions of the cars.   Your lucky if the center area under a Norwood car got anything more than a light dusting of primer.  Body color was not painted by humans, but by fixed and reciprocating spray heads along the sides and top of the spray booth.  Think of a car wash that sprays paint instead of water, no one painted the main body color by hand at the plant, except in the repair booth area to fix damage and or missed spots.  Stripes and blackout treatments were painted by hand later in the process.
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 07, 2012, 03:45:46 PM
Thanks Mark.  The information from you and JohnZ are very helpful in understanding how things should be restored. 

For incorrect black underbody restorations, I have two theories how it started:

Theory 1)  In the GM instructions, Step 1 (etching) and possibly Step 2 (rust inhibiting compound) left areas that were black.   This caused people restoring cars today to believe that the underside must have black. 

Theory 2) People believed that black looked better or was more durable than primer.  They started restoring cars this way and it became accepted practice.

Out of the huge number of restoration pictures I have seen, I have only seen one underbody that was primer color.
Title: Re: GM Heritage Center Documentation
Post by: 68Zproject on January 07, 2012, 04:52:04 PM
Just to clarify, what color is the primer on the underside?
Title: Re: GM Heritage Center Documentation
Post by: jeff68 on January 07, 2012, 05:11:11 PM
... I have two theories how it started...
A third could be that is was very common (at least in the rust belt) for dealers to undercoat cars.  The underbody on my car was completely covered in black undercoating.  It sure saved the floors, so I left it.  Not factory correct for judging, but 'as-delivered' correct.
Title: Re: GM Heritage Center Documentation
Post by: NoYenko on January 07, 2012, 06:51:43 PM
David Thanks for posting the links for the documents that kind of information is a tremendous asset to us restoring cars. I researched allot of original cars trying to understand how my car was originally painted. The assembly information that JohnZ provided really answered a lot of my questions but then I looked at other clues and other cars and had more unanswered questions. 35 years ago I worked for a shop that had more original low milage original Corvettes & muscle cars come thru the doors than any other shop that I can remember at that time. This ingrained me with a believe that originality & restoring it as it left the factory is most important to my restoration.
My car came out of Colorado, was covered underneath with oil, grease, and sandy dirt. All of witch saved the bottom of the car finish. After cleaning it I found really nice original BLACK paint. At the front of the tunnel and low on the firewall I see grey primer misting back OVER the black paint but just 6-12" back on the bottom of the floor. The firewall blackout paint is sprayed over the grey primer above this area. This same grey primer was found inside the car and under the vinyl top. Apparent that the factory didn't paint the entire roof if it was getting a vinyl top. In the trunk area I found red oxide primer on the top of the rear seat panel and near the lock support. At that point I didn't know how I was going the paint the bottom of the car. After cleaning I believe the bottom was painted black, the outside surfaces and in the trunk were painted red oxide primer, then the topside painted panels, and inside overspray, were painted grey filler primer. I will post a couple pictures showing what I found on a Norwood car built Nov 1968.
Title: Re: GM Heritage Center Documentation
Post by: NoYenko on January 07, 2012, 07:28:45 PM
A couple other related pictures. I can't understand why there is no paint under the one exhaust hanger and I would have thought the blackout paint on the rockers would have been painted after the front end was on but this picture shows a masked line over the Lemans blue on an area covered by the fender normally.
I have other pictures if you are looking for more.
I really enjoy these kind of posts, Thanks.
George
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 07, 2012, 09:44:45 PM
Wow!  NoYenko, I did not expect to see so much black primer.  When I look at the GM instructions, the last step with primer is step 4 and it is a gray primer.  If black primer was put on it would have been done earlier in step 2 when the instructions say 4 corrosion primers were put sprayed on by hand.

Jeff68, your 3rd theory sounds reasonable too.  

I have a 4th theory: There is too much variation considering 4 corrosion primers applied in GM instruction step 2 and the gray primer applied in step 4.  To make judging guidelines uniform and make the underbody look neat and tidy, everyone should paint their underside floor pans 30-percent gloss black (and add a little overspray).

Also, I could not find specifics in JohnZ’s write up where black primer was put on.  

from JohnZ
---------------------
"Prime System: In the first prime booth, the entire body, inside and out, was manually sprayed with primer, and confined areas subject to corrosion were given a second coat of heavier primer material; this prime coat was then baked at 390F for 30 minutes. In the second prime booth, the instrument panel and rear of the shelf area (and the upper door and quarter areas of 1967-68 models) were painted interior color, and another coat of air-dry flash primer was sprayed from the belt line down. The interior color areas were masked, and the entire outer body was sprayed with gray primer-surfacer and the body was baked again at 285F for 45 minutes."

Based on the GM instructions and John’s write-up, I would expect the majority of the underbody to be gray primer.

68Zproject, you have the bottomline question:
what color is the primer on the underside?
Title: Re: GM Heritage Center Documentation
Post by: Mark on January 07, 2012, 10:02:28 PM
Black paint, or black phosphate coating?
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 07, 2012, 10:32:14 PM
I have a clearer idea on what you are saying now Mark when you wrote "Your lucky if the center area under a Norwood car got anything more than a light dusting of primer".    Step 4 gray primer was not a thorough application of primer.  Therefore when we look at the underside we are looking at whatever was put on in either Step 1 or Step 2.
Title: Re: GM Heritage Center Documentation
Post by: Oaklyss on January 08, 2012, 02:17:40 AM
My floors have lots of overspray. Where overspray was knocked off, its black under:
(http://i145.photobucket.com/albums/r206/OAKLYSS/69%20SS%20detail%20shots/DSC02716.jpg)

(http://i145.photobucket.com/albums/r206/OAKLYSS/69%20SS%20detail%20shots/DSC02715.jpg)

(http://i145.photobucket.com/albums/r206/OAKLYSS/wellandblackout.jpg)

Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 08, 2012, 03:06:23 AM
My floors have lots of overspray. Where overspray was knocked off, its black under:

It's black primer, correct?

Is your car a Norwood car?  What's the build date?

My car is a 01B, 2nd week of Jan 1969.
Title: Re: GM Heritage Center Documentation
Post by: Oaklyss on January 08, 2012, 03:13:08 AM
It's whatever GM put there ;D

O4A LA car. Original paint, the overspray is factory applied.
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 08, 2012, 03:27:06 AM
It's whatever GM put there ;D

HA!!!   :)

At first I thought that it's "Four corrosion resistant primers, specially formulated" and "hand sprayed".  But you don't see black all over the rest of the body.

However, when I read the rest of step 2 it states "Lower areas considered especially vulnerable are coated with another rust inhibiting compound."

So my best guess is that the black areas are "rust inhibiting compound".





Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 08, 2012, 05:15:33 AM
Maybe it's "hammerite" which came out in 1962 ?
Title: Re: GM Heritage Center Documentation
Post by: ChrisM on January 08, 2012, 05:53:36 AM
Maybe it's "hammerite" which came out in 1962 ?

Wow!  You may be on to something.  I googled that.  Hammerite is zinc phosphate based. 
Title: Re: GM Heritage Center Documentation
Post by: NoYenko on January 08, 2012, 02:52:35 PM
Many years ago we used GM restoration paint in Gal. cans for Corvette restorations. Currant # 1050104 available from dealer or other suppliers. I don't know if it still matches the paint from 30 years ago.
Maybe someone has recently used it and can give feed back.
George
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 08, 2012, 03:21:10 PM
At a place I used to work, we did material analysis with machines like this one:
http://www.helmut-fischer.de/independent/31/XAN_en.asp (http://www.helmut-fischer.de/independent/31/XAN_en.asp)
And this one:
http://www.helmut-fischer.de/independent/31/XUV773_en.asp (http://www.helmut-fischer.de/independent/31/XUV773_en.asp)
If I had samples of each and I could get a few favors at Fischer, a comparison could be made between black samples from a couple cars and Hammerite.

….or…..maybe I am nuts and should just go 30% gloss black and call it a day.
Title: Re: GM Heritage Center Documentation
Post by: bcmiller on January 08, 2012, 05:20:31 PM
David, if you have connections, I think that would be a worthwhile project.  I don't have a survivor car, but hopefully others would agree to submit samples for analysis.
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 08, 2012, 07:48:42 PM
I have connections and used to work at Fischer.  I would have to talk to my former boss and see if he would agree to some testing.  I don't think it would be a big deal for him though.

However, if JohnZ or anyone else knows what "another rust inhibiting compound" actually is, this might be resolved quickly.



Title: Re: GM Heritage Center Documentation
Post by: 68Zproject on January 08, 2012, 10:57:46 PM
Just to clarify, what color is the primer on the underside?

 
Black paint, or black phosphate coating?

Or whatever it's called.  The question for my LOS car would be; what color was underneath it before the exterior paints were applied?  And what was the color of the primer that was sprayed that "oversprayed" onto the bottom of the car?  From my reading, there should be a lot more of this on LOS cars as they were higher off the ground when sprayed.
Title: Re: GM Heritage Center Documentation
Post by: 68camaroz28 on January 08, 2012, 11:28:26 PM
I was just under a 68 Z/28 survivor this week observing things for our restoration and the only color other than the body overspray underneath was black. Our Oct. 69 Norwood car is a TN never undercoated Camaro and other than the Lemans Blue overspray it's all black. I honestly do not remember working on a car with a gray bottom but that does not mean they do not exist as I'm sure they do somewhere.
Title: Re: GM Heritage Center Documentation
Post by: JohnZ on January 08, 2012, 11:39:40 PM
I would have thought the blackout paint on the rockers would have been painted after the front end was on but this picture shows a masked line over the Lemans blue on an area covered by the fender normally.

The body was painted by Fisher, including the rocker blackout, in their Paint Shop; the front sheet metal was painted separately by Chevrolet, in their Paint Shop, including the continuation of the rocker blackout on the lower fender, before the front sheet metal was assembled to the body, as noted in the Assembly Manual in the Z21 and Z22 sections.
Title: Re: GM Heritage Center Documentation
Post by: 68Zproject on January 09, 2012, 12:18:50 AM
So John, do you know what the color of the bottom of the Camaro should be and what was this color made of?  And what was the color of the primer that was sprayed by hand that overspryed under the car?  Was this color more pronounced on LOS cars vs. NOR cars because of the height on the lines?
Title: Re: GM Heritage Center Documentation
Post by: NoYenko on January 09, 2012, 12:58:39 AM
JohnZ you never seize to amaze me with your knowledge & memory. There it is noted on page 453. I heard your pretty involved in NCRS, do you know if the Corvette guys are using the GM restoration paint, or how they feel about it?
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 09, 2012, 03:42:13 AM
So John, do you know what the color of the bottom of the Camaro should be and what was this color made of?  And what was the color of the primer that was sprayed by hand that overspryed under the car?  Was this color more pronounced on LOS cars vs. NOR cars because of the height on the lines?

Hopefully John can answer this and of course John would know much better than I would.

but going by the GM instructions, comments, and pictures of the cars posted, here is my conjecture:

step 2 - black primer and in vulnerable areas a black compound like Hammerite is applied by hand

step 4 - the entire body is painted in gray primer. Again, applied by hand.  Since in a NOR car the underbody is only 18" off the ground and not easily accessible, areas that recieved gray primer were inconsistent.  I have no idea about a LOS car but I would think they could easily end up with a lot more gray primer.

I started out believing that underbodies were supposed to be gray primer color and right now I believe they are mostly black with some sections that have gray primer.

Title: Re: GM Heritage Center Documentation
Post by: JohnZ on January 09, 2012, 03:53:57 PM
JohnZ you never seize to amaze me with your knowledge & memory. There it is noted on page 453. I heard your pretty involved in NCRS, do you know if the Corvette guys are using the GM restoration paint, or how they feel about it?

I don't recall the primer colors, although Van Nuys probably used a different formulation due to their environmental restrictions.

The GM Restoration paint (black) really didn't have much application on the Corvette, as the only black used on the body (other than exterior black) was the underhood blackout on the firewall, inner fenders, and underside of the hood; it was a flattened cheap black lacquer, sprayed after the final bake oven, which air-dried. On the exterior, Corvette used red oxide primer, then gray primer, then sealer, then color lacquer, and there was no paint of any kind on the underbody - just raw fiberglass.
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 09, 2012, 06:26:37 PM
I wonder if color pictures exist showing the underside on either the NOR or LOS assembly lines.

In John's terrific write-up, he has these two pictures:

#1
    (http://www.camaros.org/images/assembly/assembly-raise.jpg)

#2
    (http://www.camaros.org/images/assembly/assembly-final2.jpg)

#3    GM has this picture which is similar to picture #1 - Van Nyes (LOS) assembly line for 67 Camaros
    (http://img.photobucket.com/albums/v239/pratt1/67-camaro.jpg)

has anyone ever seen a color picture that is similar to picture #2 ?
Title: Re: GM Heritage Center Documentation
Post by: Steve Shauger on January 09, 2012, 07:24:04 PM
The underbodies on most of the original cars I've looked out are primarily (90%) black as the last "primer" and then have body color overspray over the black to varying degrees. Usually the upper areas such as over the axle and the tunnel areas have more grey primer, rather than black. That's typically what I have seen but in a few cases I have seen primarily grey primer on the lower areas and black primer in the tunnel and overaxle areas. What I recommend is closely examining the car prior to resto, document your findings with pictures and replicate what you have found during the restoration. The pics NOYENKO posted is typical of what I have seen and serve as a good reference.
Title: Re: GM Heritage Center Documentation
Post by: Steve Shauger on January 10, 2012, 05:06:56 PM
Heres a couple of pics. Ironically a few pics are from a Yenko we certified a few years ago.
Title: Re: GM Heritage Center Documentation
Post by: Steve Shauger on January 10, 2012, 05:15:28 PM
I believe the photos I posted show the grey primer was applied first and then the black . The black in most cases did not cover the "hard to reach upper areas" such as upper tunnel, over axle and lower firewall.
Title: Re: GM Heritage Center Documentation
Post by: DavidS on January 10, 2012, 05:45:18 PM
Great pictures Steve! 

It would be great if what the pictures show could be matched against the GM instructions.  Is it possible that the gray primer in step 4 went on over black primer in step 2?



Title: Re: GM Heritage Center Documentation / Underbody color
Post by: firstgenaddict on February 06, 2012, 04:48:13 PM
The drop offs and rear rails extensions are gray as well.
04C Norwood

(http://inlinethumb34.webshots.com/47713/2390722000059464720S600x600Q85.jpg)

(http://inlinethumb04.webshots.com/1539/2368492000059464720S600x600Q85.jpg)

(http://inlinethumb23.webshots.com/47254/2031049130059464720S600x600Q85.jpg)

(http://inlinethumb63.webshots.com/48382/2474035010059464720S600x600Q85.jpg)


Title: Re: GM Heritage Center Documentation / Underbody color
Post by: Hans L on February 06, 2012, 09:12:37 PM
Pictures of my '69 Van Nuys 04B underside as well as the factory green firewall - go figure.   Whatever the paint material was (primar or paint), the underside was clearly black throughout with significant body color overspray.  The car is an original SoCal car - never spending anytime outside of the area.  I found no signs of non-factory undercoating anywhere. 

Regarding the green firewall - my only guess is they ran out of black paint that day and dark green was the closest alternative. 

Title: Re: GM Heritage Center Documentation / Underbody color
Post by: firstgenaddict on May 21, 2014, 05:23:25 PM
Pictures of my '69 Van Nuys 04B underside as well as the factory green firewall - go figure.   Whatever the paint material was (primar or paint), the underside was clearly black throughout with significant body color overspray.  The car is an original SoCal car - never spending anytime outside of the area.  I found no signs of non-factory undercoating anywhere.  

Regarding the green firewall - my only guess is they ran out of black paint that day and dark green was the closest alternative.  
If your car is dark green then the firewall just got sprayed with body color... there was an original 68 Sequoia green car with complete Sequoia green firewall.

Title: Re: GM Heritage Center Documentation / Underbody color
Post by: Hans L on May 22, 2014, 11:32:31 PM

Regarding the green firewall - my only guess is they ran out of black paint that day and dark green was the closest alternative. 
If your car is dark green then the firewall just got sprayed with body color... there was an original 68 Sequoia green car with complete Sequoia green firewall.


69 69 Cortez Silver Car.   I've seen a few others LA Cars, same build week (Daytona Yellow & another silver LA car) that also had the green fire wall.  It's metallic as well!

Hans
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: firstgenaddict on May 23, 2014, 03:42:26 AM
That would be great to see the judges looking at an unrestored Daytona Yellow car with a Green firewall...

Ford during the 30's-40's used left overs of paint, mixed it all together and used it to dip parts for shipment to dealers etc, most of the time it was black or dark brown, I am sure there were short instances of some off colors.
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: janobyte on May 23, 2014, 10:38:34 AM
I'll post some pics of mine before it gets covered up . Red Oxide final before bare metal--liberal from mid car back/frame rails.traces of gray was in the tunnel/front.Black--body color overspray/liberal---undercoat. Took it down with water based stripper, which pretty much allowed 1 layer at a time to come off. The Ash Gold weeped . Almost half the underbody had body color overspray on the driver's side,very little on the pass. My bodyman went with another supplier for the GM blackout, suppose to be higher quality---very happy with the shade. Guy doing my car wanted to replicate the overspray underneath ,I'm out on that.
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: NoYenko on May 23, 2014, 10:27:14 PM
Since this thread was brought up again I thought I would post some pictures of my floor after painting. I had found black on the bottom with grey primer overspray on the front 20". The slightly duller firewall blackout paint sprayed over the grey primer on the firewall vertical surface. The sides of the floor and rear frame rails received body color overspray. I could not figure out how to accurately reproduce the grey paint runs found at the firewall to floor seam so I didn't do that. George
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: NoYenko on May 23, 2014, 10:46:15 PM
Couple more shots.
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: Mike S on May 23, 2014, 11:08:59 PM
George,

  Did you spray the car? If so, approximately what spray fan size did you use and how much overlap did you do under the rockers with the blue coat to get that factory look?

Thanks,
Mike
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: NoYenko on May 23, 2014, 11:50:35 PM
Mike, I did not spray it but ill try to find out the answer. The car was painted Ohare Auto Body in Bensenville IL. I thought they did an outstanding job, other than covering up most of the lightly stamped date codes. But I can be slightly anal sometimes. George
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: janobyte on May 24, 2014, 12:38:18 AM
Very pretty under your car George. Blue works :D.....Ash Gold does not >:(

What you wrote falls exactly in line what I found under my Z. Wondered why the gray ? ( and front 20% pretty accurate)

under my tank (trunk) was barely any coverage what so ever ,had the car sat out over the years , it would have long since rotted away. presented almost as bare metal with very lite surface rust.

Looks like you pretty much nailed what it might have looked like before the undercoating.
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: Scott69Z on January 02, 2015, 02:44:56 AM
No Yenko did you use base clear to reproduce the overspray? It looks fantastic I would like to reproduce the overspray on my floor just not sure how to go about it.
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: NoYenko on January 02, 2015, 01:43:03 PM
Scott, I had the paint store mix up some single stage paint and sprayed it on with an Air Brush so I could have better control of the spray pattern. Happy New Years, guys. George
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: Oaklyss on January 03, 2015, 02:29:12 AM
So good to see overspray being properly sprayed on the underbody!

Now here is the proper rocker black-out on original paint car, mistakes and all:

(http://i145.photobucket.com/albums/r206/OAKLYSS/69%20SS%20detail%20shots/ec193a4e-5bb8-4328-8a63-bbcbd7ed4e4c_zps03a3a0c5.jpg) (http://s145.photobucket.com/user/OAKLYSS/media/69%20SS%20detail%20shots/ec193a4e-5bb8-4328-8a63-bbcbd7ed4e4c_zps03a3a0c5.jpg.html)

(http://i145.photobucket.com/albums/r206/OAKLYSS/69%20SS%20detail%20shots/wellandblackout_zpsf045e8f1.jpg) (http://s145.photobucket.com/user/OAKLYSS/media/69%20SS%20detail%20shots/wellandblackout_zpsf045e8f1.jpg.html)

(http://i145.photobucket.com/albums/r206/OAKLYSS/69%20SS%20detail%20shots/rockerblackout.jpg) (http://s145.photobucket.com/user/OAKLYSS/media/69%20SS%20detail%20shots/rockerblackout.jpg.html)

(http://i145.photobucket.com/albums/r206/OAKLYSS/69%20SS%20detail%20shots/passengerrocker.jpg) (http://s145.photobucket.com/user/OAKLYSS/media/69%20SS%20detail%20shots/passengerrocker.jpg.html)

(http://i145.photobucket.com/albums/r206/OAKLYSS/69%20SS%20detail%20shots/leftrearrocker.jpg) (http://s145.photobucket.com/user/OAKLYSS/media/69%20SS%20detail%20shots/leftrearrocker.jpg.html)

Title: Re: GM Heritage Center Documentation / Underbody color
Post by: 68 RS/SS Ragtop on October 13, 2015, 11:38:41 AM
I've read though this a few times and am trying to summarize as this would apply to may car which is at the "paint the underside stage". So, the consensus here is 68 Norwood car would have a gray primer bottom with primer showing through approximately 20% of the final black corrosion coat. The 20% is made up of around the lower firewall, tunnel, over the rear axle and toward the rear valence/and back end under the gas tank. Instead of spraying a Hammerite coating, if I were to spray a 30% gloss black coat to simulate, then after that, sprayed color and let the color overspray fall where it may, it should be on track as showing something considered technically correct. (Or at least an acceptable attempt :)  )
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: cook_dw on October 13, 2015, 11:56:36 AM
Here are pics of the underside of my L78 car.  NOR 03D   I am currently doing a preservation of it and have been working on cleaning the underside of the car.  Over 25hrs to this point and nowhere near complete.  I think George nailed it on replicating the look.. 

These are the before pics.

(http://i1310.photobucket.com/albums/s649/cook_dw/1968%20Rallye%20Green%20L78%20Camaro/IMG_4009_zps3nwhiahh.jpg)

(http://i1310.photobucket.com/albums/s649/cook_dw/1968%20Rallye%20Green%20L78%20Camaro/IMG_4053_zpsiij5t3b6.jpg)

(http://i1310.photobucket.com/albums/s649/cook_dw/1968%20Rallye%20Green%20L78%20Camaro/IMG_4054_zpsvfxoehtz.jpg)

http://i1310.photobucket.com/albums/s649/cook_dw/1968%20Rallye%20Green%20L78%20Camaro/IMG_4055_zpscgjp1zxl.jpg

(http://i1310.photobucket.com/albums/s649/cook_dw/1968%20Rallye%20Green%20L78%20Camaro/IMG_4056_zpsedf3cgee.jpg)



Here are the afters on areas

(http://i1310.photobucket.com/albums/s649/cook_dw/1968%20Rallye%20Green%20L78%20Camaro/IMG_4070_zpsvzyrri8t.jpg)

(http://i1310.photobucket.com/albums/s649/cook_dw/1968%20Rallye%20Green%20L78%20Camaro/IMG_4067_zpsdtvc9hn8.jpg)

(http://i1310.photobucket.com/albums/s649/cook_dw/1968%20Rallye%20Green%20L78%20Camaro/IMG_4072_zpsjbupslmv.jpg)

(http://i1310.photobucket.com/albums/s649/cook_dw/1968%20Rallye%20Green%20L78%20Camaro/IMG_4074_zpsidoxp1dr.jpg)

(http://i1310.photobucket.com/albums/s649/cook_dw/1968%20Rallye%20Green%20L78%20Camaro/IMG_4082_zpsvavczwsk.jpg)




More can be seen here.

http://www.yenko.net/ubbthreads/ubbthreads.php/topics/622058/all/preservation-project-green-mac (http://www.yenko.net/ubbthreads/ubbthreads.php/topics/622058/all/preservation-project-green-mac)
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: NoYenko on October 13, 2015, 12:20:17 PM
Darrel, Great pictures of a nice original car
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: 69Z28-RS on October 13, 2015, 01:58:50 PM
Darrel,

What are you using to clean the underside of the car?  Are you using an abrasive of any kind? or just detergents and water?
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: cook_dw on October 13, 2015, 02:19:34 PM
Citrus Degreaser and oven cleaner on heavy areas but do not leave the oven cleaner on for long periods of time..  Once clean I am going back over it with Mequiars #7 polish.  Honestly if it wasnt for the car being as original as it is; it would have been easier to just restore it but thats not how I roll..   8)   ::)   ;D
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: 69Z28-RS on October 13, 2015, 02:24:51 PM
Citrus Degreaser and oven cleaner on heavy areas but do not leave the oven cleaner on for long periods of time..  Once clean I am going back over it with Mequiars #7 polish.  Honestly if it wasnt for the car being as original as it is; it would have been easier to just restore it but thats not how I roll..   8)   ::)   ;D

You are correct that 'restoring' it would be easier..  I know it to be a fact..  :) 
PS.  I used simple green diluted, and then rinsed and dried and it took off the dirt/grime and left original surfaces.. (I laid under mine for a few weeks of nights as well).. :)
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: BillOhio on October 13, 2015, 04:41:53 PM
I will add a couple pictures from the bottom of my car. The burgandy over spray showed up well. Lighter grey was in tunnel and footwells.
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: BillOhio on October 13, 2015, 04:44:16 PM
More pics
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: ko-lek-tor on January 24, 2016, 12:43:26 AM
BillOhio in another post regarding paint stripes fading into the cowl(http://www.camaros.org/forum/index.php?topic=14083.0), which the topic went to underside overspray,  I had some pics of my Yellow car's, Nor3E, underside to share, but for reference sake because no one would do a search for this topic and expect to end up in a cowl paint page and not to hi-jack that thread. This must of been cleaning out the paint gun on the bottom side of the car day. Look past the rust and scale, it is an Ohio car that sat out a lot.
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: ko-lek-tor on January 24, 2016, 12:44:48 AM
more
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: crowe-t on October 07, 2019, 05:02:40 AM
I found this picture in this attached link.  It shows light gray primer on the bottom with black in the transmission tunnel and under the rear axle and body overspray.

Is this correct for a '68 Camaro?

https://www.chevydiy.com/how-to-paint-your-chevy-camaro-restoration-guide/
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: 69Z28-RS on October 07, 2019, 12:42:58 PM
I can't respond re '68 Camaro underbody, but the photo and description is very similar to how my '69 (Sept '69 Norwood) Camaro is  on the underside.
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: crowe-t on October 07, 2019, 01:55:03 PM
Do you know why there's black in the transmission tunnel?
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: 169INDY on October 07, 2019, 02:45:09 PM
Is this correct for a '68 Camaro?

LOS OR NOR built Car ??

JIM
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: 69Z28-RS on October 07, 2019, 03:34:57 PM
Do you know why there's black in the transmission tunnel?

Based on where the black was (uncovered by any other paint), the 'black' seems to be the anti-corrosion coating, applied to the entire car after thorough cleaning but before any primer or paint.  I believe it is the result of the 'phosphating' step as described in JohnZ's paint shop description (excerpted here and referenced below)
..   
"The Paint Shop is broken down into phosphate, prime, sealing, and color departments; the body was suspended from an overhead conveyor with hooks at the firewall and at the ends of the rear frame rails through the phosphate system, and was transferred to a steel carrying truck before the prime system that carried it through the rest of the Paint Shop and through the Trim Shop.
Phosphate System: The raw body shell passed through a seven-stage phosphate system, where it went through a series of enclosed high-pressure hot spray stages where it was washed to remove all the oils and debris from stamping, welding, brazing, soldering, and grinding operations, then the body was coated with a hot iron phosphate solution which "etched" the metal and provided "teeth" for paint adhesion. The final stage was a de-ionized hot water rinse and blow-off, followed by a drying oven on the way to the prime booth.

Prime System: In the first prime booth, the entire body, inside and out, was manually sprayed with primer, and confined areas subject to corrosion were given a second coat of heavier primer material; this prime coat was then baked at 390F for 30 minutes. In the second prime booth, the instrument panel and rear of the shelf area (and the upper door and quarter areas of 1967-68 models) were painted interior color, and another coat of air-dry flash primer was sprayed from the belt line down. The interior color areas were masked, and the entire outer body was sprayed with gray primer-surfacer and the body was baked again at 285F for 45 minutes. The cowl vent panel was hung in the side window opening on wire hooks all the way through the paint process."

John's full description is found here:     http://www.camaros.org/assemblyprocess.shtml
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: crowe-t on October 07, 2019, 09:11:56 PM
I can't respond re '68 Camaro underbody, but the photo and description is very similar to how my '69 (Sept '69 Norwood) Camaro is  on the underside.

Can you post some pictures of your '69 Camaros underside?
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: 69Z28-RS on October 08, 2019, 03:40:44 AM
My car has never been on a roll over rack, so I don't have a 'full floor photo'.  All my photos were taken laying on the floor under the jacked up car.   I've posted them before, so you might look for my previous posts on the subject... (I did look on my computer tonight, but with 1000's of photos I was unable to find them quickly and I don't have time to look further)...
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: crowe-t on October 08, 2019, 05:12:06 AM
Does anyone have a picture or pictures of a '68 Camaro's undercarriage? 

Did a '68 Camaro's undercarriage have gray primer or just the black and body overspray?

Was the transmission tunnel of a '68 Camaro black or gray primer?
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: 69Z28-RS on October 08, 2019, 10:54:25 PM
My car has never been on a roll over rack, so I don't have a 'full floor photo'.  All my photos were taken laying on the floor under the jacked up car.   I've posted them before, so you might look for my previous posts on the subject... (I did look on my computer tonight, but with 1000's of photos I was unable to find them quickly and I don't have time to look further)...

OK ..  I spent a couple of hours today wading thru my old posts to find the ones where I posted photos of my floor...   See the thread at:
http://www.camaros.org/forum/index.php?topic=10627.msg81153#msg81153

Title: Re: GM Heritage Center Documentation / Underbody color
Post by: crowe-t on October 09, 2019, 12:33:37 AM
My car has never been on a roll over rack, so I don't have a 'full floor photo'.  All my photos were taken laying on the floor under the jacked up car.   I've posted them before, so you might look for my previous posts on the subject... (I did look on my computer tonight, but with 1000's of photos I was unable to find them quickly and I don't have time to look further)...

OK ..  I spent a couple of hours today wading thru my old posts to find the ones where I posted photos of my floor...   See the thread at:
http://www.camaros.org/forum/index.php?topic=10627.msg81153#msg81153

Thanks for the link!

Does the black in the transmission tunnel go under the front floor pans like that picture I posted above with the yellow overspray?
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: 69Z28-RS on October 09, 2019, 02:01:22 AM
Did you read the link on the production process by John Hinckley? 

IMO, the black was EVERYWHERE since that was the Phosphating/rust prevention step, PRIOR to primer of any kind, and prior to paint of course.   First was the phosphating (rust prevention) - everywhere, Then the gray primer (heavier in some spots than others) and almost totally lacking in the rear portion of the driveshaft tunnel, heavy where the gas tank was going, and heavy gray primer in the transmission portion of the tunnel (and probably down from the firewall - prior to the body paint on the body and firewal... everything else on the floor was 'overspray from priming/painting the body, and the 'last overspray' under the floor would have been the black from the rocker blackout for those cars that got it...

I wasn't there when they painted these cars, but based on John's description of the overall process- and there's no one better to describe how the plant functioned on these cars! ... and what I observed when cleaning under my car, that is what I think they did.  Of course, there could also be variations from plant to plant (Norwood and LA), and possibly variations during the year and from car to car?

The overall 'thing' I learned was that there was NO attention for 'pretty' detail UNDER the car.  All the paint/coatings/overspray/etc UNDER the car came from 1) GM/Fisher's attempt to rustproof and seal the body shell, And 'residue' from the body paint process...  Buyers didn't inspect UNDER the car prior to purchase...
Title: Re: GM Heritage Center Documentation / Underbody color
Post by: 169INDY on October 09, 2019, 02:04:18 AM
Does anyone have a picture or pictures of a '68 Camaro's undercarriage? 

Did a '68 Camaro's undercarriage have gray primer or just the black and body overspray?

Was the transmission tunnel of a '68 Camaro black or gray primer?


Yes, I have some (Dec 1967) build 68 limited angle shots in my GILMORE Z build thread, Keep in Mind this is a LOS Z28 and has tons of body color around the underbody as described as a result of the Method Mark mentions.

JIM