Subframe Crisis

[68camaroz28]

Hey Gary. Since my car has already been painted and I am doing everything backwards, I am leaning towards just painting the bottom black. Was think a 60% gloss. Considering the same for the subframe, firewall & inner fenders.

Research your thinking 60% gloss black Mike as I thought sub-frames, firewall, and underneath were 30% gloss black. That is what I have observed and noted. while many other components were in the 60% gloss black liike the inner fenders and a-arms.

[69Z28freak]

Hey Gary. Since my car has already been painted and I am doing everything backwards, I am leaning towards just painting the bottom black. Was think a 60% gloss. Considering the same for the subframe, firewall & inner fenders.

Research your thinking 60% gloss black Mike as I thought sub-frames, firewall, and underneath were 30% gloss black. That is what I have observed and noted. while many other components were in the 60% gloss black liike the inner fenders and a-arms.

Hey Chick, last time I painted the subframe firewall and inner fenders, SEM Trim Black and I was not crazy about the result. I was told that it is about 30% gloss. However. Having an original paint Z/28 in my garage, shows me that SEM Trim black does not look like the original finishes on this particular car. Even though the paint is 43 years old, it still has a deeper black look and a bit of a sheen.

I am going to try to match the finishes as on the original car.

Her is the original paint on the bottom of my car. It was covered for 43 years with undercoating, and when I removed the undercoating the original paint was revealed. Obviously different light affects how it looks when the picture is taken, so perhaps these pictures are not the best representation. However in person, there is a noticeable difference between all of the finishes. I will take a look at your build thread for a reference.



Here is a picture of what I am thinking of going with on the bottom of my car.





Here is the current finish on my car with SEM Trim Black

[69Z28-RS]

Here are a few photos of my original '69 Z28 floorpan, after a bit of cleaning in this last year; it's not perfectly cleaned, but it's clean enough that one can see the various paints which hit the floor (before lying on my back for a few weeks cleaning with simple green, water, etc, it was 'dirt'... .   
This car was never undercoated and spent it's entire life in the north Alabama area; it was driven regularly for 10 yrs or so, but since then has been in my conditioned garage.   As you can see, it has areas of black, gray and color (orange) depending on where the overspray from body painting could reach.

[69Z28-RS]

A few more photos of my original floor since someone had asked me a few months ago to post some, and I'd never taken the time to reduce photo size til now.

[Mike S]

 Those pictures are one heck of a fine example of what an original undercarriage finish is instead of the all black show paint jobs.

Mike

[69Z28freak]

My car had virtually no overspray, at least after I removed the undercoating. However when I dropped the tank, it was grey underneath. So what was the black colour? A primer of finish paint? Just curious what the paint sequence was, since I have black everywhere except under the tank.

[69Z28-RS]

JohnZ could probably respond to how the factory did it, but on mine it *seemed* to be 'black underneath'.. and it seemed to be a high quality tough black.  I suspect that was the corrosion protection for the basic body, then the gray and/or brown primers (probably overspray during body paint), and then the orange overspray... with also some 'black overspray from when they painted the rockers and firewall..  That's just my guess from what I observed while cleaning under my floor.

[69Z28freak]

JohnZ could probably respond to how the factory did it, but on mine it *seemed* to be 'black underneath'.. and it seemed to be a high quality tough black.  I suspect that was the corrosion protection for the basic body, then the gray and/or brown primers (probably overspray during body paint), and then the orange overspray... with also some 'black overspray from when they painted the rockers and firewall..  That's just my guess from what I observed while cleaning under my floor.

Sounds about right to me Gary. You car looks great underneath. The original paint Z28 in our shop has no other color present except black underneath. Noi trace of any primer yet, but I have not looked under the gas tank yet. For the most part all of the black looks the same, however I could be wrong since its all black.

[Mike S]

The under body finish was been discussed in detail a few times and has led to some interesting facts. It seems the color of the primer varied from year to year with the color ranging from gray dominant to black dominant and some owners reported red. Which plant (NOR vs. LOS) likely had differences too in the color though I doubt it mattered what was used.
This URL explains the body paint process especially the underbody in the Paint Shop Operations section: http://camaros.org/assemblyprocess.shtml#fisher

Mike

[lynnbilodeau]

Mine was NOT black underneath.  Very dark gray back to the axle then much lighter gray.  I duplicated it using Sherwin Williams Q seal mixed with a bit of RM black lacquer.  It is a much tougher finish than straight lacquer.  For the lighter gray axle back, I just didn't add any black lacquer.
Not sure why the two colors.   Also the only place on mine where overspray was clearly evident was forward of the rear axle.  Must have had some really high pressure guns going.  I painted with hvlp so my overspray didn't reach that far.  Because my car is black, the overspray on the front 2/3 would barely show anyway.

Funny that it would have shown up there because whoever painted mine missed part of the lower tail panel completely with top coat.

[BillOhio]

My car had 2 colors of primer. Lighter gray in front foot area and the top of the tunnel. I did a lot of looking for paint and used sikkens rally black. Turned out gorgeous. I wanted a paint that would use hardener and a good sheen. Its a little pricey but very pleased

[69Z28-RS]

...
Funny that it would have shown up there because whoever painted mine missed part of the lower tail panel completely with top coat.

The lower the painter got to get under the valence and rockers, the more overspray there would be on the floor....

[Sauron327]

There are many threads on here with photos and info about the various undercarrage colors, and why they vary in hue and coverage. You'll also find that a person did not shoot the car's color, it was automated.

[lynnbilodeau]

You'll also find that a person did not shoot the car's color, it was automated.

Yeah, I thought about that as I was typing.  Regardless of how it was done, someone or something missed a quite a bit of area on the bottom of the tail panel.

[69Z28-RS]

There are many threads on here with photos and info about the various undercarrage colors, and why they vary in hue and coverage. You'll also find that a person did not shoot the car's color, it was automated.

What year did chevrolet begin using automated robots for painting car bodies?