1969 Z/28 firewall crayon marks, question?

[1968 Z28]

Bill,
your the man, great pics. So I know you see the Camaros at shows with all the paint dabs and crayon marks all over everything after it has the finish paint, (ex: engine compartment) . I have the "PTB" stamps on my firewall, but would any 69 camaro have left the factory with crayon marks on the black paint on the firewall, or were the crayon marks only and always used before paint?

and a follow up question: why do you see front license plate brackets with out the license plate but then a white "X" in crayon?

Examples of the crayon on paint build number on my 1968 07C.....

     Firewall...
                   

     Valence...
                   

     Spare tire...
                     

[william]

Our '67 Z/28 had 258 inside the lower grille panel. Vintage road test photos of ZL1 #3 show 718 written on the trans cross member.

[69Z28-RS]

When I removed my front clip, I found the number '18' hand written on the side of the cowl 'shoulder' under the driver side fender.  I've no idea what that means, but I cleaned the crud off the area without removing the number written ON the painted surface... see photo.

[Bryan302]

Thanks William and Bill.  Great Information!  If I were to use my portable blasting pot for the soda blasting, are there any special nozzles or tips designed for soda or fine material?  Does the air pressure used make a difference?  Are the grease penscil marks etched enough that you don't have to worry about removing them, even with using soda, or is this a babied process?

As Austin stated, there has been a lot of recreations to the firewalls on restored cars.  And now, especially after seeing the options found by these markings, color codes, etc.  It seems to me the best choice is to document the markings with digital photos for the restored album of what you had and where, and be done with it.  Paint the firewall back like it was, install your PBT back in the same spot, and don't add something the car didn't roll off the line with!  But, I see the beauty of this as documentation that you didn't have if you didn't find you build sheet under the back seat, which I didn't!

I think it would be cool to start a registry of these findings to see just how in depth it was.  (official CRG project addition request) How many options have been found on one firewall?  Has anyone found NC8 or JL8, etc.  It appears there has been interior and exterior options found, what determined why it needed to be there and other options were not?  What if the body was to be a heavily optioned car, how would that work out?

Why did the assembly line need to do this?  Was the build sheet not with the body yet?

Thanks,
Bryan

[BillOhio]

I used soda in a portable blaster and it worked fine. Make sure you have a good water filter. It doesn't get into metal and leaves a nice surface. When soda hits something, it turns to fine dust and blows away.I didn't clean mine until I was ready to paint. I sprayed acetone until it was running down firewall. Cleaned it off good.

[firstgenaddict]

Thanks William and Bill.  Great Information!  If I were to use my portable blasting pot for the soda blasting, are there any special nozzles or tips designed for soda or fine material?  Does the air pressure used make a difference?  Are the grease penscil marks etched enough that you don't have to worry about removing them, even with using soda, or is this a babied process?

As Austin stated, there has been a lot of recreations to the firewalls on restored cars.  And now, especially after seeing the options found by these markings, color codes, etc.  It seems to me the best choice is to document the markings with digital photos for the restored album of what you had and where, and be done with it.  Paint the firewall back like it was, install your PBT back in the same spot, and don't add something the car didn't roll off the line with!  But, I see the beauty of this as documentation that you didn't have if you didn't find you build sheet under the back seat, which I didn't!

I think it would be cool to start a registry of these findings to see just how in depth it was.  (official CRG project addition request) How many options have been found on one firewall?  Has anyone found NC8 or JL8, etc.  It appears there has been interior and exterior options found, what determined why it needed to be there and other options were not?  What if the body was to be a heavily optioned car, how would that work out?

Why did the assembly line need to do this?  Was the build sheet not with the body yet?

Thanks,
Bryan

The majority of them were written on the bare metal firewall, yes they could be seen under the black firewall paint, however few were blatantly visible even though the restoration graffiti vandals think otherwise.

[JohnZ]

Why did the assembly line need to do this?  Was the build sheet not with the body yet?

Thanks,
Bryan

The build sheet (Broadcast Copy) was a Chevrolet document, and didn't exist until the body was shipped from Fisher Body and received and checked in at the Chevrolet Body Bank. Fisher Body had their own build document (the UOIT) that only addressed Fisher Body content in their Trim Shop.

On the Chevrolet side, components that were built/processed/subassembled in off-line areas and conveyor-delivered to the main line for installation almost always had the sequence number marked on the part (or had a Broadcast Copy taped to the part) to keep the feeder lines in sequence with the main line and to be able to verify that the correct part matched up with the correct car before installing it. A feeder line "out of sequence" with the main line was a disaster, and almost always  resulted in a line stop.

Nobody on the Chevrolet side paid any attention to the VIN number, as they weren't necessarily in sequence; the location of the car in the system after the Body Bank was only described by the "sequence number", at the top left corner of the Broadcast Copy, and that's the number you frequently see written on parts. The car was physically "locked in sequence" from the Chevrolet Body Bank to the end of the line.

[BULLITT65]

Ok So these previous posts where Jerry G. found the number 22 on various parts on his car, your saying the very next car down the line that was "locked in sequence" would have had parts on it with 23 written on the body valance and spare tire? But may have not been the next vin number after Jerrys. And on Garys car if he found the number 18 then other original parts should have this same number on it?

[william]

I have a broadcast copy for an LA Z/28 with this typed notation at the bottom:

PHYSICAL SEQ FOR THE FOLLOWING JOBS WILL BE 658, 660, 659, 661 BROADCAST ARE IN THIS ORDER.

[BULLITT65]

ok, are those cars coming down the line, or are those the sequence (jobs) for the next few pieces that got put on that car?

[69Z28-RS]

Austin,

The cars/bodies were 'notated' by 'sequence number' on the production line.   This sequence number which might have gone from 001 thru 999 for example, went in sequence, then began again.  The sequence string was long enough that two cars with the same number would never be on the line at the same time.  The sequence number only had relevance for that car and for that day that it was in production.   That number is irrespective of VIN number or body number or any other number. 

(I think I've seen similar sequence numbers written in large numerals in magic marker on the build sheets in the Corvette assembly plant...)

[JohnZ]

I have a broadcast copy for an LA Z/28 with this typed notation at the bottom:

PHYSICAL SEQ FOR THE FOLLOWING JOBS WILL BE 658, 660, 659, 661 BROADCAST ARE IN THIS ORDER.

That happened occasionally - result of a release screwup in the Body Bank; as long as everyone involved "got the message", they could deal with it, but it was a huge PITA and distracted everyone from their primary focus.

[JohnZ]

Austin,

The cars/bodies were 'notated' by 'sequence number' on the production line.   This sequence number which might have gone from 001 thru 999 for example, went in sequence, then began again.  The sequence string was long enough that two cars with the same number would never be on the line at the same time.  The sequence number only had relevance for that car and for that day that it was in production.   That number is irrespective of VIN number or body number or any other number.

That's correct.  :-)

[Stingr69]

I have found "RGRN" on the firewall on my 10A "Rally Green" car.  The Interior paint color abbreviation was also written in crayon on the rear bulkhead. On this car it was "LG7" for "Light Green" interior paint/color with "X77" trim level. The crayon marks on the fire wall told Fisher Body what color to paint on the outside of the body and the rear bulkhead crayon marks told Fisher what color to paint on the inside of the shell to match the interior trim color.

This rear bulkhead marking style was used on cars built before X-Codes were being embossed on the Trim Tag.

-Mark.

[Oaklyss]

Here's an example of crayon bleed-thru on my firewall (all original paint). The "72" for Hugger Orange is seen here. Restored cars look wrong with the crayon on top of the paint, and nobody seems to be able to write as smooth as the factory workers could: