How did the factory paint our trucks?

[LongBox]

I'm still working on cleaning up my 69, and I've been machine polishing the various panels. I notice that the paint on the cowl panel is much thinner than the paint on the fenders, hood and doors. Were these trucks painted before assembly? Why would the cowl panel have thinner paint than the other panels? And, should the underside of the engine hood be painted body colour, or black?

The other question I have is what type of paint was used on the inner fenders and rad support? Was it glossy black, semi gloss, or flat black?

Any insight into this would be appreciated.

[Alex V.]

Black surfaces are most appropriately painted what Krylon used to call "semi-flat black", #1613. IIRC it became "satin" black in more recent times, but the last Krylon I sprayed wasn't worth the cap on top of it so someone else will have to chime in with better options.

[special-K]

Panel painted

Black under hood

Semi-gloss/satin/low gloss/whatever you want to call it

Restoration paint suppliers offer a chassis black. That is right for all these areas. I have used low gloss black engine enamel. Whatever brand Advanced Auto sells, Dupli-Color? The last can I bought they went and changed the name to semi-gloss. I guess it's the same, probably just some marketing BS

paint can get thinner on top surfaces because the sun is harder on them and when waxing or polishing there is more pressure placed on them. Edges/ridges go first from that.

[Keith Seymore]

Here are some squarebody assembly pics, which include some of the paint shop:

http://www.73-87.com/7387info/Assembly%20Line.htm

'67-72 pickups would have used the same process.

The operator is standing beside the vehicle, spraying (mostly horizontally) as required. As a result leading edges and the upper/lower areas get a little less paint coverage than the areas directly in front of him, because it takes more effort to reach high or bend over.

Front end sheetmetal was painted separately from the cab/box carrier (in some cases in a different area of the plant). The cowl panel was typically placed on a small fixture that went along with the hood and fenders.

K

[LongBox]

Wow, thanks for the great replies. The cowl on my truck is definitely coated more thinly than the fenders/doors and even the hood. The sun has damaged the paint on the engine hood more than the other panels, except the cowl, but for 47 year-old paint, it ain't bad.

This truck is not the one I really want, but it is so original, that painting it seems to be the wrong thing to do. The original owner did paint the underside of the hood with a glossy black, not sure why, but wish he had left it alone.

Still trying to decide which way to go on this.

[special-K]

Keith, how big a batch do they work with in each color?

[Keith Seymore]

Originally Posted by special-K

Keith, how big a batch do they work with in each color?

They used to do just one at a time (one of one color, followed by another color) but it got to be cost prohibitive to purge the lines for each color changeover.

In more modern times they batch them in quantities of four or five or six in a row, but there are limits to how many they can do. The UAW does not allow too many of certain options in a row (like A/C, or sunroofs, or manual trans) due to line side work load balance and "color" is one of those items.

K

[special-K]

Originally Posted by Keith Seymore

They used to do just one at a time (one of one color, followed by another color) but it got to be cost prohibitive to purge the lines for each color changeover.

In more modern times they batch them in quantities of four or five or six in a row, but there are limits to how many they can do. The UAW does not allow too many of certain options in a row (like A/C, or sunroofs, or manual trans) due to line side work load balance and "color" is one of those items.

K

That fits when I ordered my '92. I had it all spec'd out and wanted it Woodland Green, the fleet green, but am not a fleet account. GM said they would, but I had to wait till they had orders for at least 5 others in that color. That made me very happy and I was fine with however long it took. It took 6 weeks to start my truck. Then, once on the line it must have been sidelined (does that happen?) a time or two because it ended up taking almost 6 months to be completed. Nearer the end my dealers would call to say my truck should be coming soon. They have a list of vehicles ordered that gets updated weekly(?) or whatever, and when a vehicle drops off the list it means it has advanced toward shipping. You know all this better than me. This happened a few times, then would show back on the list. I figured my truck had a few exceptions from the norm, plus this was the late-92 first production of the 6.5TD only installed in regular cab heavy duty 2500s, 3500s and 3500HDs. I figure other fleet trucks wouldn't be SLEs, have turbo diesels, bucket seats, 5spd manual, all the camper/trailer/off road pkgs, and probably not a lot of K3500 SRWs. I only know how it was on my end, you know your end. I'm pretty sure my truck was one of a kind and waiting never bothered me. I feel I got a factory custom and left it "as built".

[SCHRUMGMC]

That is neat. I wonder if the 55-59 trucks were done the same

[Keith Seymore]

Originally Posted by SCHRUMGMC

That is neat. I wonder if the 55-59 trucks were done the same

Pretty much.

The process hasn't changed all that much since the 1930's. The manufacturers took advantage of the slow time during the depression to re-vamp the process into the body/chassis build breakup that we still use today.

K