under body brackets and mounts

[Donald S.]

hi all i am ready to prime and paint all the under bodyt mounts and brackets i know the bird cage color zinc chromate green , but its all the rest when i cleaned and readied the brackets for paint i could not determine the origional color the shifter boot retainer looks like it was also painted with zinc green but the seat mounts look like they were black and no visible paint on the body and seat belt mounts . and what about the clips that hold the insulation in the tunnel .... help please . thanks Don .

[Joe C.]

Re: under body brackets and mounts

Don,

If your body is a St. Louis assembly, then the underbody "steels" were dipped in a dilute gloss black coating (same as the seat frames), except for the rear seat mount plates, which were unpainted, or "natural". Same applies to the radiator mount, rear bulkhead stiffener, front header brace.

If your body was a Smith assembly, then all of the above were zinc chromate, except for the rear seat mount plates, which were also unpainted.

In all cases, don't forget that rivets were added after paint.

As far as the clips for the tunnel insulation, I'm not certain. Reproductions are black, but they may have been unpainted originally.

Joe

[Donald S.]

Re: under body brackets and mounts

thanks joe .. yes it is a st louis car built in july the two rear seat mounts that are natural were not rivited in to the body correct ??? mine were not and were definatly a lot rustier than any thing else under the car ... so its good to know they were natural .. thanks again Don .

[Joe C.]

Re: under body brackets and mounts

thanks joe .. yes it is a st louis car built in july the two rear seat mounts that are natural were not rivited in to the body correct ??? mine were not and were definatly a lot rustier than any thing else under the car ... so its good to know they were natural .. thanks again Don .

Correctamundo!

[John H.]

Re: under body brackets and mounts

the two rear seat mounts that are natural were not rivited in to the body correct ???

The four unpainted reinforcements for the rear seat track-to-floor attachments were originally riveted to the floor pan - see the Assembly Manual, Section 1-Bolt/Weld, Sheet B2, item #6 (and rivets, #7).

[Gary B.]

Underbody seat mount reinforcements; some not riveted

John,

I think this is one of those cases where the AIM differs from actual practice. The outboard underbody seat mount reinforcements on my '66 were not riveted in place. The inner ones were. (Or maybe it was vice versa.) I've heard similar reports from several other owners or '66s, so when I confirm the specifics with my notes when I find them, one set will go back on w/o rivets when I get to that stage of things.

Gary

[John H.]

Re: under body brackets and mounts

Gary -

More answers to this one would be interesting; all four of mine are riveted to the floor pan. The seats were the last item installed in the car before it was shipped (the car was on wheels, and had been through roll-test, toe-in, water-test, etc.), and it would have been extremely difficult and inconvenient to install the rear seat track-to-floor bolts if the seat installer had to reach blind under the car (especially with sidepipes) to position the outer plates while installing the bolt from the inside, and would have been impossible to position the inboard plates.

[Donald S.]

Re: under body brackets and mounts

those two outboard seat mounting reinforcments were not riveted on when i unbolted the seat they fell on the ground and when the floor was striped and cleaned there was no evidence of there ever being holes drilled in the floor pan for rivets ...Don

[Gary B.]

Under body brackets and mounts

Don,

What you describe is identical to my experience. i just check under my '66 to refresh my memory and it is the outboard seat mounts that were never riveted.

Gary

[Alan D.]

Re: Under body brackets and mounts

Same with my 64 - its simple (one man job) to hold the outboard plate when securing the seat. Such a method would save a rivet and the operation during production so seems reasonable.

[Gary B.]

Re: under body brackets and mounts

Joe,

You mention a "dilute gloss black coating". When judging I find that more than a few of my co-judges either want to take a deduct or make a note for gloss black paint on such items, as well as specifically for A-arms. Even though the 66 TIM&JG specifically calls out for a gloss finish on the A-arms. The 66 TIM&JG is silent on the underbody reinforcement plates. To avoid the potential deduct or confrontation at the least, I'm repainting several items semi-gloss instead of gloss black since a semi-gloss sheen doesn't seem to cause a problem with the judges in my experience.

Gary

[Joe C.]

Re: under body brackets and mounts

First photo is of the passenger (right) side, rear inboard seat bracket installed on the floorpan. Next to it is it's neighbor's, the drivers' side nut plate after rivets were drilled out and removed from the car.

I have no such similar photo of the rear outboard nut plates, but I can tell you that they has no holes for rivets. They simply have 2 threaded holes to accept the outer rear, seat bracket bolts. I did a very thorough job of sealing all openings in the birdcage/floorpan, etc. with black urethane windshield bedding compound before reassembly. I used a judicious amount to fasten the outboard nut plates to the floorpan, which also served to seal any openings. The second photo is the best I can do for the outboard nut plates. If you look closely, you'll see that there are no rivets apparent here! I just now went to the garage to check and, indeed, those outer nut plates are not riveted to the floorpan.

The third photo is my best attempt at zooming in on the area above the left side, rear outboard nut plate.

Corvette was built 5/18/65.

[Joe C.]

Re: under body brackets and mounts

Joe,

You mention a "dilute gloss black coating". When judging I find that more than a few of my co-judges either want to take a deduct or make a note for gloss black paint on such items, as well as specifically for A-arms. Even though the 66 TIM&JG specifically calls out for a gloss finish on the A-arms. The 66 TIM&JG is silent on the underbody reinforcement plates. To avoid the potential deduct or confrontation at the least, I'm repainting several items semi-gloss instead of gloss black since a semi-gloss sheen doesn't seem to cause a problem with the judges in my experience.

Gary

Gary,

There is always controversy over the degree of sheen in all black parts. There is similar controversy concerning the convertible top frame. IIRC, the TIM&JG calls for semi-gloss black paint. There, again, when I restored mine, it looked to be the same, dilute gloss black coating that I found on my seat frames. I have heard the same testimony from many others, as you probably have, too. Oddly, the Manual correctly calls for "gloss black" seat frames. Since most small parts were dipped, then why not make the reasonable assumption that these parts were all dipped in vats of the same, or similar product. In most cases, aesthetics was not the primary concern, so much as corrosion inhibition was. Lacking any accurate testimony from period line workers, all that we can do is use our best judgment based on what we perceive in unrestored original Corvettes. Unfortunately, time has not been kind to many components. Although some components might appear to have an original looking surface finish, the patina of time has changed them to varying degrees.

Joe

[John H.]

Re: under body brackets and mounts

I think we inadvertently have an "apples and oranges" discussion going on; the rear seat track attachment is totally different between '63-'66 and '67. The '63-'66 cars use a shoe-and-plate arrangement on TOP of the floor pan, with the inboard nut-plate riveted to the underbody, and the outboard nut plate is NOT riveted, and has no rivet holes in it (I expect that the outboard shoe-and-plate, nut plate, and bolts were installed in the Body Shop).

The '67 redesigned rear seat track attachment only uses bolts from above driven through the floor pan into the nut-plate on the bottom, which was riveted to the underbody.

[Joe C.]

Re: under body brackets and mounts

John,

Is your Corvette a 1967?