Still baffled by so many unpainted parts on a 63-64 chassis

[Troy P.]

In 53-62 everything was subject to the chassis blackout process. 36 GM photos of 63 chassis assembly show it was blacked out. The top of my differential, which was protected by the mounting bracket had black paint. The factory assembly manual, Section 4 sheet 4, says to make sure the end of the driveshaft yoke that slides onto the output shaft of the transmission and past the tranny rear oil seal does not get painted. That implies the rest of the driveshaft was to be painted. The 63-64 TIMJG says the exhaust system was blacked out after installation in the chassis, but none of the other parts? The TIMJG says every cast and forged part on the chassis, driveline and suspension were not painted...except sometimes the steering box and front stabilizer bar were painted. Why sometimes?

It doesn't make sense to me that only the exhaust would be blacked out and not the rest of the parts that would rust, as it was done for the 10 prior years.

I have heard the theory that all the excellent GM chassis blackout photos are from pre-production cars and production cars were not blacked out. The evidence of that is...?

For our first major update of the 53-55 TIMJG I traveled across country at my own expense to inspect and document the lowest mileage cars I could find (including cars with 1800 and 3200 miles) to ensure we knew how they came from the factory. Has anyone done that for 63-64? I'm certain super low mileage cars still exist. I saw a split window in a collection with only 9000 miles and there are members who specialize in collecting low mileage cars.

Back in the day I was able to draw blueprints of 53-55 parts from GM archives. They always specified the finish for the parts. Has anyone done that for 63-64 chassis parts?

[Bob J.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

I think with Joe being the new 63-64 team leader many things will change for the better on items you mention.
I've heard his new JG comes out this summer. Be patient.
Bob Jorjorian

[Mark F.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

The guy to ask is Larry Galloway...he doesn't post or reply here often, but if you can ever reach him on the phone as I have, you're in for a treat !

He was there in St. Louis from August 1962 to sometime in 1967, so he saw the entire '63-'64 model year production.
He has written two books on C2 production; one of which focuses on '63s - both of which I have purchased and have read with great interest. I'd suggest you buy them and read them - they're very interesting and come from somebody who WAS there - not speculating on what might have happened.

Also, I have done considerable research on John Hinckley's C2 Assembly Process Presentations (available in the Database of Restoration Documents [DoRD] Sticky Post); his series of Assembly Articles in the Corvette Enthusiast magazine; and along w/ my own independent research I have done on the St. Louis Plant layouts during those years.

My question from a production standpoint is: "Where was the paint booth for painting the fully assembled Chassis before body drop ?" No plant layout I have ever seen has a paint booth anywhere near the Chassis line.

I too, have read about the pre-production chassis painting - and have seen those chassis in LIGHTED, VENTILATED PAINT BOOTHS.

I have to believe those pre-pub shots involved the transfer of fully-assembled chassis across the body shop floor over to the south of the plant to the main paint booths for that to have happened. Having worked in many automotive assembly plants, that certainly seems like something that would NOT pass muster for scaled-up production operations...but I wasn't there, so I have no onsite knowledge.

As for '53 to '62s - didn't those frames arrive at St. Louis already painted black - so additional blackout was not necessary except for mufflers ? I don't know...

As always, our Corvette hobby is full of mysteries

[Troy P.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

Thank you both for your replies. Good info for sure. To bad John is no longer with us. He was a frequent poster and super knowledgeable. I will see if I can contact Larry. Hopefully those updating the TIMJG have done so
I've spent 80 hours making those chassis parts bare steel and presentable but don't want to do any assembly until I know what NCRS thinks vs. what I think. It would have been way easier to paint them.

[Mark F.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

Thank you both for your replies. Good info for sure. Too bad John is no longer with us. He was a frequent poster and super knowledgeable. I will see if I can contact Larry. Hopefully those updating the TIMJG have done so...I've spent 80 hours making those chassis parts bare steel and presentable but don't want to do any assembly until I know what NCRS thinks vs. what I think. It would have been way easier to paint them.

Hi Troy,

Totally agree about John !

I came very close to getting something I really wanted when he told me he thought he had a plant layout he could share with me that had all the work stations identified.

He said, "All I have to do is find it !" alas, that was not to happen...

As a followup to my previous paint booth comments, the image below is from his C2 Assembly Process presentation. I think this image was originally in Pete Licastro's book "Birthplace of a Legend".

Anyhow, the magenta rectangles show where the paint booths are in relation to the green outlined Chassis Line area.
Assuming the layout is correct for the way things looked for 1963 model year production, there's no way production could have maintained the output required if Chassis had to be rolled over to any of those paint booths; paint them; and then get them back over to the Body Drop station at the end of the Chassis Line.

I (as well as you ) would love to know what the logistics were to get those "black painted" Chassis photos in a paint booth and back for Body Drop.

I'd also like to know why they felt that was necessary...

Good luck on your quest - and let us know what you find out !
St. Louis Plant Layout Paint Booths highlighted_001.jpg

[Troy P.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

The frames for all years came to the assembly line painted. Why were they painted? Obviously to avoid rust. Not all the other parts of the chassis were painted when they were delivered to the line. So after the chassis was assembled it was blacked out on the line in 53-62. Why would it not be in 1963?

Why would only the exhaust system be blacked out? Why would just "some" of the steering boxes and lower half of the rag joint be painted? Why would only "some" of the sway bars be painted? Why would the assembly manual warn not to get paint on part of the driveshaft yoke if the driveshaft was not painted on the assembly line?

It seems that GM logically believed it would be harder to sell cars that had parts already rusting. (Keep in mind 63 was the first year for IRS and customers may well have been inclined to look under the car) Outside suppliers were told (per my experience looking at parts blueprints) to paint or plate parts to protect them. It also seems that GM maybe didn't paint parts they manufactured in house and protected them in the chassis blackout process.

Rather than wonder why they would blackout the chassis in 63, I believe a better question would be, "Why wouldn't they?"

BTW I am not suggesting the chassis was blacked out in 64 and later years. I have no knowledge of those years.

If one is to use factory layout to form an opinion it would be important to determine how the floor was laid out in 63 and not any other year. In anycase, I'm curious what "underbodies from basement" means in the floor plan. Is the "underbody" the body or the floor pan or the chassis? If its the assembled chassis it could have been blacked out in the basement before being flipped over upstairs.

[Mark F.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

The frames for all years came to the assembly line painted. Why were they painted?... Lots of Chassis were stacked outside subject to the elements...Obviously to avoid rust. ...

If one is to use factory layout to form an opinion it would be important to determine how the floor was laid out in 63 and not any other year. In anycase, I'm curious what "underbodies from basement" means in the floor plan. Is the "underbody" the body or the floor pan or the chassis? If its the assembled chassis it could have been blacked out in the basement before being flipped over upstairs.

Troy,

It is the floor pan Underbody Off-Line Subassembly: the job number was assigned from the run sheet and applied, bracket/reinforcement riveting for seat mounts, luggage stop panel, seat belt reinforcements, shifter hole reinforcement, console brackets, power window cup brackets, body mount bolt reinforcements, parking brake lever brackets, jack retainers, shoulder belt reinforcements, N03 brackets/holes/side filler panels/inner wheelhouse patch panels/jack brackets/rear bulkhead rework, convertible rear bulkhead rework and top frame brackets, quarter trim panel brackets, deck lid latch strikers, console screw brackets, tunnel heat insulator retainers, splash pan brackets, etc. Nearly 200 parts and rivets required.

The assembled Underbody panel was then sent up to main floor level and loaded/bolted to pedestals on steel body build truck.

[Duke W.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

Back in that era it was common to see surface rust on frames and chassis parts on new cars in the dealer lots, especially during the winter months. Cars were not expected to last more than 10 years or about 100K miles before major components like engines and transmissions gave out making the car uneconomical to repair. The same is true today except 15-20 years and 150K-300K is achieveable.

The "paint" applied by A. O. Smith on the frames was asphalt based, soluble in paint thinner, and not very durable. The "blackout" was rather haphazard and not expected to last much beyond customer delivery, especially during winter months in the snowbelt were salt application on roads was common.

Back in the day people said "Corvettes dont rust". That applies to the body, but not the frame and suspension parts, and we all know now that the frame kickup area and trailing arms are vulnerable and frames have literally rusted in half.

Duke

[Troy P.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

Yes, rust is the answer why any part was plated or painted. (But still wonder after restoring 5 cars why some fasteners were natural and not cad or phosphate.) The frame is an obvious example that everyone agrees with was painted to protect from rust. But everyone also agrees (apparently per the TIMJG) with the brake drums, brake backing plates, a-arms, rear crossmember, rear springs, differential mount plate, fuel tank straps, trailing arms, etc being painted as well. Were all those parts left outside for weeks too? Or were they indoors with all the other parts the TIMJG says were not painted or plated? Just guessing they were indoors. If so, why were they painted black and not others?

It looks to me that all the parts said not to be painted were castings or forgings that were made by GM and not an outside supplier. That might be a big clue as to why they arrived on the assembly line without paint.

If you have ever been to a plant where castings and forgings are done, especially back in the day, they are dark and VERY dirty. Then, from looking at all those parts laid out on my shop floor, I see everyone, except the coil springs which I don't think GM made, required machining after casting or forging. The machining required spraying with oil to keep the parts and tooling cool and lubricated. So putting two and two together, my theory is those plants did not have the capability to clean and paint parts. That was far from their main jobs.

If GM was concerned about selling cars without rusting before the sale they may have solved that via chassis blackout once assembled, like they did 53-62. The fact that the parts were oily could explain why the paint didn't stick well, along with cheapy paint used, and thus find parts some suspect were never painted. On the other hand, maybe GM was smart enough to figure the oil would protect them and they didn't need paint.

Having been a major contributor to 2 TIMJG updates (not 63-64) I know they have errors. My suspicion why it is said that the steering box and sway bar were only "sometimes" painted is that some contributor had proof positive that they were painted but that didn't match the thinking of whoever had the final say on the TIMJG update. So "sometimes" was used to solve that. My other key thought on the chassis blackout or not question is the process could apply only to 63 or even only to early 63 and not to 64. The manual covers both years and it is certainly possible the process changed...especially after IRS was no longer such a new thing buyers wanted to see under the car.

[Alan D.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

So a little from John;
"I'm with you, Michael - that gooey/sticky "chassis black" paint (originally P/N 3686683, "Underbody Protective Coating") was used for many years at St. Louis, both in the basement for the '63-'64 rear suspension, and at the end of the Chassis Line, just prior to Body Drop, for chassis blackout. Engineering-specified coverage reduced dramatically in '65 with the introduction of disc brakes, to little more than the outside of the mufflers."

Also there exists 64 pictures of the rear suspension being chassis black, but I do not write the rules.


The material was sprayed from 55-gallon drums adjacent to the line with Johnstone pumps mounted in the drums, with airless spray guns; there was NEVER any sort of "mitting" - that "legend" persists in spite of the fact that it never happened.

Chevrolet-Buffalo used the same material to paint the steering linkage, and it never dried there either - it was still sticky at the toe-in pit at St. Louis.

[Jack M.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

Why would only the exhaust system be blacked out?

Was the blackout paint ONLY applied as a rust preventative... or was it also done for visual & cosmetic purposes?
Since the C2 blackout was significantly reduced in later years, at that point, it seemz mainly for visual aspects.
(their primary focus was hiding the outer visible SIDES of the muffler, to obtain a 'cleaner' side image)

If you haven't already, consider reviewing the many original C2 undercarriage/chassis images in Noland's book.

[Troy P.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

The problem as I understand it, from a factory originality point of view, is it is theorized the many photos in Noland's book and available on the web were preproduction. (There is also a series of something like 32 1963 chassis photos on the web.) The TIMJG describes all cast and forged parts as natural and not painted as shown in the photos. That thinking prevails for judging purposes. But doesn't seem correct to me.

I have prepared all those parts as natural. But before I start assembly I want to make sure which direction will be NCRS correct in the future.

[Alan D.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

Just follow the JG, leave them natural. At some point the JG will catch up with facts and it will easy enough to blackout those natural parts, but not the opposite. Those of us who support the extensive 63/64 blackout are in the wood shed, so just follow what they want.

[Troy P.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

Problem is the parts are well preserved with several applications of a spray oil so they won't rust. It will be very difficult to degrease them on the car so the paint will stick. Off the car I can soak them in a tumbler tank with degreaser and then detergent. That's my quandary.

[Bob J.]

Re: Still baffled by so many unpainted parts on a 63-64 chassis

Troy, suspension parts and exhaust were not painted with paint.
The coating was more like asphalt undercoat, but grainy, not lumpy.
Mineral spirits or gunk washed it off.
It was not the same as blackout paint,like on fiberglass under the hood.
Bob Jorjorian