Correct Horn Fasteners

[JohnZ]

All of the hood latch support bolts are #3960314, including the bolt for the R.H. horn; the L.H. horn used #3846202. All are black phosphate.

I respectfully disagree, because I have 5 documented cars (4 unrestored and one needing restoration), all produced from 9B to 10C (of 68) that were built with the horns secured with zinc plated bolts with serrated washers. My point to Mike was that 10c is the lastest built car I have found . Just an FYI, but all examples were built at Norwood.

I don't disagree - the horn bolts may have been changed under a local Engineering deviation to the zinc variety to improve grounding, but it's unusual that the A.I.M. sheet was never revised to reflect the change if it was indeed permanent - it shows both horn bolts as black phosphate, although different part numbers.

[IZRSSS]

Each of my horns has a different fastener...go figure? One exactly like Chicks with an S on the head (Zinc), and this one with an anchor on the head and I'm pretty sure... is black phosphate.
 

[68camaroz28]

Marty, that anchor bolt sure looks like a zinc coating under the captured washer... When was your Camaro built?

[IZRSSS]

12A LA Build...
Is a Black Phosphate finish baked into the metal? If so, you are probably correct. If it is BP It shouldn't have lost its color right? 

[68camaroz28]

12A LA Build...
Is a Black Phosphate finish baked into the metal? If so, you are probably correct. If it is BP It shouldn't have lost its color right? 

Phosphate is a chemical process and not a baked on process. No I do not think it should have lost its color like the thread and underside show if it was a phosphate bolt originally. I have taken rusted bolts and upon removing the rust (evaporust) it is nomally quite evident to still see the dark gray phosphate appearance. Your bolt Marty appears to have been coated with something while it was in place (threaded in) hence the upper portion of thread and underside so zinc looking. Maybe someone sprayed some coating on it while it was threaded into something other than the car? Just my thoughts!?!?

[IZRSSS]

Maybe someone sprayed some coating on it while it was threaded into something other than the car? Just my thoughts!?!?

I think your probably spot on...I think I'll hire you to find my cars owner...

[1968 Z28]

12A LA Build...
Is a Black Phosphate finish baked into the metal? If so, you are probably correct. If it is BP It shouldn't have lost its color right?  

Phosphate is a chemical process and not a baked on process. No I do not think it should have lost its color like the thread and underside show if it was a phosphate bolt originally. I have taken rusted bolts and upon removing the rust (evaporust) it is nomally quite evident to still see the dark gray phosphate appearance. Your bolt Marty appears to have been coated with something while it was in place (threaded in) hence the upper portion of thread and underside so zinc looking. Maybe someone sprayed some coating on it while it was threaded into something other than the car? Just my thoughts!?!?

Hi Chick....A word on EvapoRust.  Leave the metal in long enough and the EvapoRust will deposit its own layer of phosphate.  I have taken bolts and scrubbed and buffed them until they were down to the bare metal....put them back into the EvapoRust, and leave them there for awhile and they will come out with a back coating on them.

In some of their literature they even state that this will happen.

[69Z28-RS]

I've noticed the same thing..  chemically, I doubt there's a huge difference in the makeup of 'Evaporust' and 'the phosphating' solution sold by Plametto enterprises....