Factory undercoating on a '72

[tfiv]

The exterior of mine have been walnut shell blasted. They had only paint on the outside.

[Guru]

Tom,

On this picture, it's hard to tell if the underside of the floorpan was painted black over body color silver and has faded over time, or if it was originally left body color silver without a black ovecoat:

Attachment 74821

I was under the strong impression that 72 cars had the underside of the floorpan painted black over the body colour.

Also, would you mind giving the car's chassis number (via PM if you prefer)?

I'm trying to make sure I get it right on my 72S (Chassis 0871) and I suddenly got nervous looking at this pic!

Thanks very much, Guru

[tfiv]

Hi Guru, I was never all black. It looks like they just reached under and sprayed the outer parts and didn't worry about the center. You can see the contours that stick down have black paint indicating the car was not up in the air very far when the spraying was done. Everything you see here was preserved by nice layer of grime. My washer is low pressure, it doesn't take off paint.

[vipergruen]

On the brochure for My72 there's a picture of a car being treated with the undercoating. It seems to me that the undercoating was applied by brush by a couple of guys on the already painted shell.

Attachment 74872

Andrea

[Tom F.]

Andrea,

I believe that the photo of the men with the brushes is earlier, when they used a bituminous undercoating, applied by brush. By 72, they were using a PVC undercoating with a spray gun. The body color paint was applied after the PVC. As the pictures of tfiv's car show, they saved on paint wherever possible, leaving the PVC on the insides of the bumpers and the bottom of the floor pan almost naked. The black paint on tfiv's car was applied as the final step in finishing the body, to mask the areas where body color paint would seem out of place, such as below the rocker panel trim, inside the the wheel wells and behind the front grilles.

There have been some other threads on where the black paint was applied, but tfiv's pictures take the cake. Tom from Oregon, I hope that you'll post more.

By the way, I think that the correct PVC material is availiable from Wurth. It's "Underbody Seal Beige," and I bought some from Stoddard not long ago.

Tom F from Massachusetts

[edmayo]

From what I have seen on all the cars that I deal with, and pictures that I have studied I agree with Tom F 100%. It seems they were slowly figuring out what steps they could eliminate to save money? Realize the first 911's were done just like a 356, same undercoat, same method, then they started changing materials and methods and soon we get to the 73 model year where they decide to not put black over the body colored undercoat anymore in the engine compartment. Why go that extra step, leave it body color. Then eventually they stopped blacking out the wheel wells. The next thing ya know they'll start cooling with water.....oh wait, they've already done that

[911T1971]

On the brochure for My72 there's a picture of a car being treated with the undercoating. It seems to me that the undercoating was applied by brush by a couple of guys on the already painted shell.

Attachment 74872
Andrea

Andrea, this 72 Brochure is using photos from the 1970 (and again 1971) factory brochure. So its either on 69MY or 70MY cars.
My 71 just looks like that, with original undercoat, slightly faded to grey.

Tom,
On this picture, it's hard to tell if the underside of the floorpan was painted black over body color silver and has faded over time, or if it was originally left body color silver without a black ovecoat:

The brown residue might be a rust proof spray, long gone and faded to brown.
Still, its interesting that the factory left it almost unpainted but still blacked out the wheel wells.
In 70/71 they did have problems with 2.2l cars which undercoat cracked but to see the 72 floorpan almost naked is new to me.
Is this 72 100% original and never restored , never received any touch-up's ?

[vipergruen]

Karim, you're right, I was just wondering where I had already seen that photo, and indeed is the same in the earlier brochures.

Tom F, I agree with you, the undercoating in the photos is not brush-applied.

Andrea

[gsjohnson]

My original 72T looks the same as tfiv's pics that he posted, with one exception. My wheel wells show body color in several places. They are not solid black as his pics depict.

[robmog]

tom,
i agree the bottom is not black but is the bottom body color?
the underside of my car was brownish grey, no sign of body color anywhere.
wheelwells and engine compartment are black.
i stripped the bottom by hand and was vigilant, i never saw anything other than black primer on metal then undercoat. i assumed any other paint had worn off.