C2 & C3 Build sheet properties / forensics

[Dan Pepper]

I recently contacted a forensic document specialist to ask about ressurrecting faded text on tank stickers. I would like to provide him more info about the properties of the origian stickers:

What transfer technique (mechanical process, carbon sheets, etc.?) was used to print the multiple part forms?

What was the specific type & weight of paper used?

Also, what type of was glue used to affix them to gas tanks (water based, chemical based, etc.)

Anybody have this information or know where I might find it?

(And no, I'm not trying to recrecreate 'original' build sheets...)

Thanks!

[Joe L.]

Re: C2 & C3 Build sheet properties / forensics

Dan-----

I can provide some of the information.

The multiple sheets were made using CARBON PAPER between the sheets in some sort of "snap-apart set" (probably like a Moore Business Forms type of thing).

The paper was quite thin. I would say that it's about 12 or 14 pound paper. Certainly, it wasn't heavier than 16 pound.

I believe that the adhesive used to affix these papers to the top of the fuel tank was a neoprene solvent type cement (i.e. like 3M weatherstrip cement). I'm not sure about this, though. I don't think that it was the same as the water soluble cement used for the window sticker, but it's possible that it was.

[Tom R.]

Re: C2 & C3 Build sheet properties / forensics

Dan & Joe:

It's essential to differentiate time periods when discussing build sheets because data processing changed the methods as 60 methods transitioned into 70 technologies. 1973 marked a significant change in what showed up on tanks. The factory went from Corvette Order Copy to Corvette manifest...from portrait style to landscape style...from a sales document to a factory production document.

By late 70's, the factory was using the multi-part preprinted forms which I can recall from other manufacturing work was light weight. At the St Louis plant...we've been able to account for at least seven copies. But, I've handled 78 original build sheets and they are pretty sturdy and I would venture to say at least 20 pound. In fact the attach photo shows such a document tucked into a 78 Pace Car strut bracket than when removed...reeked of differntial fluid. It was pretty firm with virtually no wear.

[Mike M.]

Re: C2 & C3 Build sheet properties / forensics

If you provided him a sample, shouldn't HE be providing US with these details?
H. a. N. D.

[Joe L.]

Re: C2 & C3 Build sheet properties / forensics

Tom------

The later style build sheets were thicker paper and they were not produced from a multi-sheet carbon set. The build sheet that I have for my 1969 is a thin paper and not heavier than 16 pound stock. I'd say it's a lot lighter---like, maybe, 12 pound stock. This type of paper stock is typical of multi-part forms which use carbon paper between each sheet of the set. It's especially true of carbon sets with many sheets. It's a very practical thing; if the paper were too thick, you'd never get the impression to go through to the last forms in the set.

I believe that this sort of form was used at least through 1972.

[Dan Pepper]

Re: C2 & C3 Build sheet properties / forensics

The forensic service is very expensive - $350/hr. (yes, that's hour...). These are professionals who are hired as expert witnesses. The lab uses CSI- type chemical & photo techniques to decipher altered, imprinted or obliterated type. The intent is to gather information to present up-front to hopefully alieviate "spending" too much time narrowing methods for detecting/ressurrecting faded type. That is unless the "us" in your email suggests you might want to kick-in to help determine the best process/technique to use!

[Kevin M.]

[Dan Pepper]

Re: C2 & C3 Build sheet properties / forensics

Good point, Kevin. I've already mentioned if they could devise techniques that works, this group could keep their lab very busy. I'll keep you guys informed should anything positive comes of this.

[Warren F.]

Re: C2 & C3 Build sheet properties / forensics

I believe there is also a change of color print on Corvette Order Copies in the '68 thru '72 era. Original '68,'69,'70 docs seem to be black print. '71 & '72 seem to be a blue color, due to the back of the Corvette Order Copy being carbon backed, and earlier sheets not.